From 7e8931c3c2a8c58c3434d1949449242e28c9235c Mon Sep 17 00:00:00 2001
From: Dan Freeman <dfreeman@salsify.com>
Date: Mon, 21 Nov 2022 15:25:40 +0100
Subject: [PATCH 1/6] Drop `hbs` support in `ember-template-imports`

---
 .../-private/dsl/integration-declarations.d.ts               | 5 -----
 .../-private/environment/index.ts                            | 2 +-
 .../-private/environment/transform.ts                        | 2 +-
 3 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/packages/environment-ember-template-imports/-private/dsl/integration-declarations.d.ts b/packages/environment-ember-template-imports/-private/dsl/integration-declarations.d.ts
index 603ab19bb..979954531 100644
--- a/packages/environment-ember-template-imports/-private/dsl/integration-declarations.d.ts
+++ b/packages/environment-ember-template-imports/-private/dsl/integration-declarations.d.ts
@@ -31,8 +31,3 @@ type EELLinkTo = typeof Globals.LinkTo;
 declare module '@ember/routing' {
   export interface LinkTo extends EELLinkTo {}
 }
-
-import 'ember-template-imports';
-declare module 'ember-template-imports' {
-  export function hbs(contents: TemplateStringsArray): unknown;
-}
diff --git a/packages/environment-ember-template-imports/-private/environment/index.ts b/packages/environment-ember-template-imports/-private/environment/index.ts
index cdb179191..735c9a7bc 100644
--- a/packages/environment-ember-template-imports/-private/environment/index.ts
+++ b/packages/environment-ember-template-imports/-private/environment/index.ts
@@ -14,7 +14,7 @@ export default function emberTemplateImportsEnvironment(
 
   return {
     tags: {
-      'ember-template-imports': {
+      '@glint/environment-ember-template-imports/-private/tag': {
         hbs: {
           typesModule: '@glint/environment-ember-template-imports/-private/dsl',
           specialForms: {
diff --git a/packages/environment-ember-template-imports/-private/environment/transform.ts b/packages/environment-ember-template-imports/-private/environment/transform.ts
index 30178308a..feae6589c 100644
--- a/packages/environment-ember-template-imports/-private/environment/transform.ts
+++ b/packages/environment-ember-template-imports/-private/environment/transform.ts
@@ -94,7 +94,7 @@ function addTagImport(f: ts.NodeFactory, sourceFile: ts.SourceFile): ts.SourceFi
           f.createImportSpecifier(false, f.createIdentifier('hbs'), f.createIdentifier(GLOBAL_TAG)),
         ])
       ),
-      f.createStringLiteral('ember-template-imports')
+      f.createStringLiteral('@glint/environment-ember-template-imports/-private/tag')
     ),
     ...sourceFile.statements,
   ]);

From ce5a668fd134f84a4bd6e23999cac7f100e7d577 Mon Sep 17 00:00:00 2001
From: Dan Freeman <dfreeman@salsify.com>
Date: Mon, 21 Nov 2022 15:27:05 +0100
Subject: [PATCH 2/6] Stop using deprecated TS AST builders

TypeScript had to rework a few bits of their AST in light
of how decorators shook out for stage 3.
---
 .../-private/environment/transform.ts                          | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/packages/environment-ember-template-imports/-private/environment/transform.ts b/packages/environment-ember-template-imports/-private/environment/transform.ts
index feae6589c..b4bc6ede2 100644
--- a/packages/environment-ember-template-imports/-private/environment/transform.ts
+++ b/packages/environment-ember-template-imports/-private/environment/transform.ts
@@ -85,7 +85,6 @@ function repairAncestry(node: ts.Node, parent: ts.Node = node.parent): ts.Node {
 function addTagImport(f: ts.NodeFactory, sourceFile: ts.SourceFile): ts.SourceFile {
   return f.updateSourceFile(sourceFile, [
     f.createImportDeclaration(
-      [],
       [],
       f.createImportClause(
         false,
@@ -163,8 +162,6 @@ function buildStaticBlockForTemplate(
   template: ts.TaggedTemplateExpression
 ): ts.Node {
   return f.createClassStaticBlockDeclaration(
-    [],
-    [],
     f.createBlock([f.createExpressionStatement(template)])
   );
 }

From 8aa5429e49348f7040fb391ae1b8eff266049ec5 Mon Sep 17 00:00:00 2001
From: Dan Freeman <dfreeman@salsify.com>
Date: Mon, 21 Nov 2022 17:09:58 +0100
Subject: [PATCH 3/6] Use `<template>` in tests that reference the ETI
 environment

---
 .../core/__tests__/cli/build-watch.test.ts    | 130 ++++---
 packages/core/__tests__/cli/build.test.ts     | 329 ++++++++----------
 .../core/__tests__/cli/incremental.test.ts    |  26 +-
 .../test-utils/src/composite-project.ts       |   1 +
 4 files changed, 225 insertions(+), 261 deletions(-)

diff --git a/packages/core/__tests__/cli/build-watch.test.ts b/packages/core/__tests__/cli/build-watch.test.ts
index ef16c472d..95bd12325 100644
--- a/packages/core/__tests__/cli/build-watch.test.ts
+++ b/packages/core/__tests__/cli/build-watch.test.ts
@@ -4,7 +4,7 @@ import { stripIndent } from 'common-tags';
 import stripAnsi = require('strip-ansi');
 import { afterEach, beforeEach, describe, expect, test } from 'vitest';
 
-import { Project, BASE_TS_CONFIG, INPUT_SCRIPT, setupCompositeProject } from '@glint/test-utils';
+import { Project, BASE_TS_CONFIG, INPUT_SFC, setupCompositeProject } from '@glint/test-utils';
 
 const BUILD_WATCH_TSCONFIG = {
   ...BASE_TS_CONFIG,
@@ -56,7 +56,6 @@ describe('CLI: watched build mode typechecking', () => {
       let code = stripIndent`
         import '@glint/environment-ember-template-imports';
         import Component from '@glimmer/component';
-        import { hbs } from 'ember-template-imports';
 
         type ApplicationArgs = {
           version: string;
@@ -65,14 +64,14 @@ describe('CLI: watched build mode typechecking', () => {
         export default class Application extends Component<{ Args: ApplicationArgs }> {
           private startupTime = new Date().toISOString();
 
-          public static template = hbs\`
+          <template>
             Welcome to app v{{@version}}.
             The current time is {{this.startupTime}}.
-          \`;
+          </template>
         }
       `;
 
-      project.write(INPUT_SCRIPT, code);
+      project.write(INPUT_SFC, code);
 
       let watch = project.buildWatch({ reject: true });
       let output = await watch.awaitOutput('Watching for file changes.');
@@ -85,7 +84,6 @@ describe('CLI: watched build mode typechecking', () => {
       let code = stripIndent`
         import '@glint/environment-ember-template-imports';
         import Component from '@glimmer/component';
-        import { hbs } from 'ember-template-imports';
 
         type ApplicationArgs = {
           version: string;
@@ -94,15 +92,15 @@ describe('CLI: watched build mode typechecking', () => {
         export default class Application extends Component<{ Args: ApplicationArgs }> {
           private startupTime = new Date().toISOString();
 
-          public static template = hbs\`
+          <template>
             Welcome to app v{{@version}}.
             The current time is {{this.startupTime}}.
             <p>Unclosed tag.
-          \`;
+          </template>
         }
       `;
 
-      project.write(INPUT_SCRIPT, code);
+      project.write(INPUT_SFC, code);
 
       let watch = project.buildWatch({ reject: false });
       let output = await watch.awaitOutput('Watching for file changes.');
@@ -111,7 +109,7 @@ describe('CLI: watched build mode typechecking', () => {
 
       let stripped = stripAnsi(output);
       let error = stripped.slice(
-        stripped.indexOf('index.ts'),
+        stripped.indexOf('index.gts'),
         stripped.lastIndexOf(`~~~${os.EOL}`) + 3
       );
 
@@ -123,7 +121,6 @@ describe('CLI: watched build mode typechecking', () => {
       let code = stripIndent`
         import '@glint/environment-ember-template-imports';
         import Component from '@glimmer/component';
-        import { hbs } from 'ember-template-imports';
 
         type ApplicationArgs = {
           version: string;
@@ -135,14 +132,14 @@ describe('CLI: watched build mode typechecking', () => {
         export default class Application extends Component<{ Args: ApplicationArgs }> {
           private startupTime = new Date().toISOString();
 
-          public static template = hbs\`
+          <template>
             Welcome to app v{{@version}}.
             The current time is {{truncate this.startupTime 12}}.
-          \`;
+          </template>
         }
       `;
 
-      project.write(INPUT_SCRIPT, code);
+      project.write(INPUT_SFC, code);
 
       let watch = project.buildWatch();
       let output = await watch.awaitOutput('Watching for file changes.');
@@ -151,15 +148,15 @@ describe('CLI: watched build mode typechecking', () => {
 
       let stripped = stripAnsi(output);
       let error = stripped.slice(
-        stripped.indexOf('index.ts'),
+        stripped.indexOf('index.gts'),
         stripped.lastIndexOf(`~~~${os.EOL}`) + 3
       );
 
       expect(output).toMatch('Found 1 error.');
       expect(error.replace(/\r/g, '')).toMatchInlineSnapshot(`
-        "index.ts:17:36 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
+        "index.gts:16:36 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
 
-        17     The current time is {{truncate this.startupTime 12}}.
+        16     The current time is {{truncate this.startupTime 12}}.
                                               ~~~~~~~~~~~~~~~~"
       `);
     });
@@ -168,7 +165,6 @@ describe('CLI: watched build mode typechecking', () => {
       let code = stripIndent`
         import '@glint/environment-ember-template-imports';
         import Component from '@glimmer/component';
-        import { hbs } from 'ember-template-imports';
 
         type ApplicationArgs = {
           version: string;
@@ -177,14 +173,14 @@ describe('CLI: watched build mode typechecking', () => {
         export default class Application extends Component<{ Args: ApplicationArgs }> {
           private startupTime = new Date().toISOString();
 
-          public static template = hbs\`
+          <template>
             Welcome to app v{{@version}}.
             The current time is {{this.startupTime}}.
-          \`;
+          </template>
         }
       `;
 
-      project.write(INPUT_SCRIPT, code);
+      project.write(INPUT_SFC, code);
 
       let watch = project.buildWatch({ reject: true });
 
@@ -193,14 +189,14 @@ describe('CLI: watched build mode typechecking', () => {
 
       await pauseForTSBuffering();
 
-      project.write(INPUT_SCRIPT, code.replace('this.startupTime', 'this.startupTimee'));
+      project.write(INPUT_SFC, code.replace('this.startupTime', 'this.startupTimee'));
 
       output = await watch.awaitOutput('Watching for file changes.');
       expect(output).toMatch('Found 1 error.');
 
       await pauseForTSBuffering();
 
-      project.write(INPUT_SCRIPT, code);
+      project.write(INPUT_SFC, code);
 
       output = await watch.awaitOutput('Watching for file changes.');
       expect(output).toMatch('Found 0 errors.');
@@ -236,7 +232,6 @@ describe('CLI: watched build mode typechecking', () => {
 
     let mainCode = stripIndent`
       import Component from '@glimmer/component';
-      import { hbs } from 'ember-template-imports';
       import A from '@glint-test/a';
       import B from '@glint-test/b';
 
@@ -247,45 +242,42 @@ describe('CLI: watched build mode typechecking', () => {
       export default class Application extends Component<{ Args: ApplicationArgs }> {
         private startupTime = new Date().toISOString();
 
-        public static template = hbs\`
+        <template>
           Welcome to app v{{@version}}.
           The current time is {{this.startupTime}}.
           <A/>
           <B/>
-        \`;
+        </template>
       }
     `;
 
     let aCode = stripIndent`
-      import { hbs } from 'ember-template-imports';
       import C from '@glint-test/c';
 
-      const A = hbs\`Hello! <C />\`;
+      const A = <template>Hello! <C /></template>;
       export default A;
     `;
 
     let bCode = stripIndent`
-      import { hbs } from 'ember-template-imports';
-      const B = hbs\`Ahoy!\`;
+      const B = <template>Ahoy!</template>;
       export default B;
     `;
 
     let cCode = stripIndent`
-      import { hbs } from 'ember-template-imports';
 
       const add = (a: number, b: number) => a + b;
 
-      const C = hbs\`{{add 123 456}}\`;
+      const C = <template>{{add 123 456}}</template>;
       export default C;
     `;
 
     beforeEach(async () => {
       projects = await setupCompositeProject();
 
-      projects.main.write(INPUT_SCRIPT, mainCode);
-      projects.children.a.write(INPUT_SCRIPT, aCode);
-      projects.children.b.write(INPUT_SCRIPT, bCode);
-      projects.children.c.write(INPUT_SCRIPT, cCode);
+      projects.main.write(INPUT_SFC, mainCode);
+      projects.children.a.write(INPUT_SFC, aCode);
+      projects.children.b.write(INPUT_SFC, bCode);
+      projects.children.c.write(INPUT_SFC, cCode);
     });
 
     afterEach(async () => {
@@ -315,29 +307,29 @@ describe('CLI: watched build mode typechecking', () => {
           await pauseForTSBuffering();
 
           projects.main.write(
-            INPUT_SCRIPT,
+            INPUT_SFC,
             mainCode.replace('{{this.startupTime}}', '{{this.startupTime}')
           );
 
           output = await watch.awaitOutput('Parse error');
           let stripped = stripAnsi(output);
           let error = stripped.slice(
-            stripped.indexOf('index.ts'),
+            stripped.indexOf('index.gts'),
             stripped.lastIndexOf(`~~~${os.EOL}`) + 3
           );
           expect(error).toMatchInlineSnapshot(`
-            "index.ts:15:32 - error TS0: Parse error on line 3:
+            "index.gts:14:32 - error TS0: Parse error on line 3:
             ...s {{this.startupTime}.    <A/>    <B/>
             -----------------------^
             Expecting 'CLOSE_RAW_BLOCK', 'CLOSE', 'CLOSE_UNESCAPED', 'OPEN_SEXPR', 'CLOSE_SEXPR', 'ID', 'OPEN_BLOCK_PARAMS', 'STRING', 'NUMBER', 'BOOLEAN', 'UNDEFINED', 'NULL', 'DATA', 'SEP', got 'INVALID'
 
-            15     The current time is {{this.startupTime}.
+            14     The current time is {{this.startupTime}.
                                               ~~~~~~~~~~~"
           `);
 
           await pauseForTSBuffering();
 
-          projects.main.write(INPUT_SCRIPT, mainCode);
+          projects.main.write(INPUT_SFC, mainCode);
 
           output = await watch.awaitOutput('Watching for file changes.');
           expect(output).toMatch('Found 0 errors.');
@@ -353,16 +345,16 @@ describe('CLI: watched build mode typechecking', () => {
 
           await pauseForTSBuffering();
 
-          projects.children.a.write(INPUT_SCRIPT, aCode.replace('<C />', '<C>'));
+          projects.children.a.write(INPUT_SFC, aCode.replace('<C />', '<C>'));
 
           output = await watch.awaitOutput('Watching for file changes.');
           let stripped = stripAnsi(output);
           let error = stripped.slice(
-            stripped.indexOf('index.ts'),
+            stripped.indexOf('index.gts'),
             stripped.lastIndexOf(`;${os.EOL}`) + 1
           );
           expect(error).toMatchInlineSnapshot(`
-            "index.ts:4:22 - error TS0: Unclosed element \`C\`: 
+            "index.gts:3:28 - error TS0: Unclosed element \`C\`: 
 
             |
             |  <C>
@@ -370,12 +362,12 @@ describe('CLI: watched build mode typechecking', () => {
 
             (error occurred in 'an unknown module' @ line 1 : column 7)
 
-            4 const A = hbs\`Hello! <C>\`;"
+            3 const A = <template>Hello! <C></template>;"
           `);
 
           await pauseForTSBuffering();
 
-          projects.children.a.write(INPUT_SCRIPT, aCode);
+          projects.children.a.write(INPUT_SFC, aCode);
 
           output = await watch.awaitOutput('Watching for file changes.');
           expect(output).toMatch('Found 0 errors.');
@@ -391,27 +383,27 @@ describe('CLI: watched build mode typechecking', () => {
 
           await pauseForTSBuffering();
 
-          projects.children.c.write(INPUT_SCRIPT, cCode.replace('456}}', '456}'));
+          projects.children.c.write(INPUT_SFC, cCode.replace('456}}', '456}'));
 
           output = await watch.awaitOutput('Parse error');
           let stripped = stripAnsi(output);
           let error = stripped.slice(
-            stripped.indexOf('index.ts'),
+            stripped.indexOf('index.gts'),
             stripped.lastIndexOf(`~~~${os.EOL}`) + 3
           );
           expect(error).toMatchInlineSnapshot(`
-            "index.ts:5:25 - error TS0: Parse error on line 1:
+            "index.gts:3:31 - error TS0: Parse error on line 1:
             {{add 123 456}
             -------------^
             Expecting 'CLOSE_RAW_BLOCK', 'CLOSE', 'CLOSE_UNESCAPED', 'OPEN_SEXPR', 'CLOSE_SEXPR', 'ID', 'OPEN_BLOCK_PARAMS', 'STRING', 'NUMBER', 'BOOLEAN', 'UNDEFINED', 'NULL', 'DATA', got 'INVALID'
 
-            5 const C = hbs\`{{add 123 456}\`;
-                                      ~~~"
+            3 const C = <template>{{add 123 456}</template>;
+                                            ~~~"
           `);
 
           await pauseForTSBuffering();
 
-          projects.children.c.write(INPUT_SCRIPT, cCode);
+          projects.children.c.write(INPUT_SFC, cCode);
 
           output = await watch.awaitOutput('Watching for file changes.');
           expect(output).toMatch('Found 0 errors.');
@@ -429,24 +421,24 @@ describe('CLI: watched build mode typechecking', () => {
 
           await pauseForTSBuffering();
 
-          projects.main.write(INPUT_SCRIPT, mainCode.replace('<A/>', '<A @foo="bar" />'));
+          projects.main.write(INPUT_SFC, mainCode.replace('<A/>', '<A @foo="bar" />'));
 
           output = await watch.awaitOutput('Watching for file changes.');
           let stripped = stripAnsi(output);
           let error = stripped.slice(
-            stripped.indexOf('index.ts'),
+            stripped.indexOf('index.gts'),
             stripped.lastIndexOf(`~~~${os.EOL}`) + 3
           );
           expect(error).toMatchInlineSnapshot(`
-            "index.ts:16:5 - error TS2554: Expected 0 arguments, but got 1.
+            "index.gts:15:5 - error TS2554: Expected 0 arguments, but got 1.
 
-            16     <A @foo=\\"bar\\" />
+            15     <A @foo=\\"bar\\" />
                    ~~~~~~~~~~~~~~~~"
           `);
 
           await pauseForTSBuffering();
 
-          projects.main.write(INPUT_SCRIPT, mainCode);
+          projects.main.write(INPUT_SFC, mainCode);
 
           output = await watch.awaitOutput('Watching for file changes.');
           expect(output).toMatch('Found 0 errors.');
@@ -462,24 +454,24 @@ describe('CLI: watched build mode typechecking', () => {
 
           await pauseForTSBuffering();
 
-          projects.children.a.write(INPUT_SCRIPT, aCode.replace('<C />', '<C @foo="bar" />'));
+          projects.children.a.write(INPUT_SFC, aCode.replace('<C />', '<C @foo="bar" />'));
 
           output = await watch.awaitOutput('Watching for file changes.');
           let stripped = stripAnsi(output);
           let error = stripped.slice(
-            stripped.indexOf('index.ts'),
+            stripped.indexOf('index.gts'),
             stripped.lastIndexOf(`~~~${os.EOL}`) + 3
           );
           expect(error).toMatchInlineSnapshot(`
-            "index.ts:4:22 - error TS2554: Expected 0 arguments, but got 1.
+            "index.gts:3:28 - error TS2554: Expected 0 arguments, but got 1.
 
-            4 const A = hbs\`Hello! <C @foo=\\"bar\\" />\`;
-                                   ~~~~~~~~~~~~~~~~"
+            3 const A = <template>Hello! <C @foo=\\"bar\\" /></template>;
+                                         ~~~~~~~~~~~~~~~~"
           `);
 
           await pauseForTSBuffering();
 
-          projects.children.a.write(INPUT_SCRIPT, aCode);
+          projects.children.a.write(INPUT_SFC, aCode);
 
           output = await watch.awaitOutput('Watching for file changes.');
           expect(output).toMatch('Found 0 errors.');
@@ -495,24 +487,24 @@ describe('CLI: watched build mode typechecking', () => {
 
           await pauseForTSBuffering();
 
-          projects.children.c.write(INPUT_SCRIPT, cCode.replace('123', '"hello"'));
+          projects.children.c.write(INPUT_SFC, cCode.replace('123', '"hello"'));
 
           output = await watch.awaitOutput('Watching for file changes.');
           let stripped = stripAnsi(output);
           let error = stripped.slice(
-            stripped.indexOf('index.ts'),
+            stripped.indexOf('index.gts'),
             stripped.lastIndexOf(`~~~${os.EOL}`) + 3
           );
           expect(error).toMatchInlineSnapshot(`
-            "index.ts:5:21 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
+            "index.gts:3:27 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
 
-            5 const C = hbs\`{{add \\"hello\\" 456}}\`;
-                                  ~~~~~~~"
+            3 const C = <template>{{add \\"hello\\" 456}}</template>;
+                                        ~~~~~~~"
           `);
 
           await pauseForTSBuffering();
 
-          projects.children.c.write(INPUT_SCRIPT, cCode);
+          projects.children.c.write(INPUT_SFC, cCode);
 
           output = await watch.awaitOutput('Watching for file changes.');
           expect(output).toMatch('Found 0 errors.');
diff --git a/packages/core/__tests__/cli/build.test.ts b/packages/core/__tests__/cli/build.test.ts
index 6d8c7bceb..f72b44ccd 100644
--- a/packages/core/__tests__/cli/build.test.ts
+++ b/packages/core/__tests__/cli/build.test.ts
@@ -10,6 +10,7 @@ import {
   CompositeProject,
   INDEX_D_TS,
   INPUT_SCRIPT,
+  INPUT_SFC,
   INPUT_TEMPLATE,
   setupCompositeProject,
 } from '@glint/test-utils';
@@ -29,7 +30,6 @@ describe('CLI: single-pass build mode typechecking', () => {
       let code = stripIndent`
         import '@glint/environment-ember-template-imports';
         import Component from '@glimmer/component';
-        import { hbs } from 'ember-template-imports';
 
         type ApplicationArgs = {
           version: string;
@@ -38,14 +38,14 @@ describe('CLI: single-pass build mode typechecking', () => {
         export default class Application extends Component<{ Args: ApplicationArgs }> {
           private startupTime = new Date().toISOString();
 
-          public static template = hbs\`
+          <template>
             Welcome to app v{{@version}}.
             The current time is {{this.startupTime}}.
-          \`;
+          </template>
         }
       `;
 
-      project.write(INPUT_SCRIPT, code);
+      project.write(INPUT_SFC, code);
 
       let checkResult = await project.build({ reject: false });
 
@@ -58,7 +58,6 @@ describe('CLI: single-pass build mode typechecking', () => {
       let code = stripIndent`
         import '@glint/environment-ember-template-imports';
         import Component from '@glimmer/component';
-        import { hbs } from 'ember-template-imports';
 
         type ApplicationArgs = {
           version: string;
@@ -67,22 +66,22 @@ describe('CLI: single-pass build mode typechecking', () => {
         export default class Application extends Component<{ Args: ApplicationArgs }> {
           private startupTime = new Date().toISOString();
 
-          public static template = hbs\`
+          <template>
             Welcome to app v{{@version}}.
             The current time is {{this.startupTime}}.
             <p>Unclosed tag.
-          \`;
+          </template>
         }
       `;
 
-      project.write(INPUT_SCRIPT, code);
+      project.write(INPUT_SFC, code);
 
       let checkResult = await project.build({ reject: false });
 
       expect(checkResult.exitCode).toBe(1);
       expect(checkResult.stdout).toEqual('');
       expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-        "src/index.ts:15:5 - error TS0: Unclosed element \`p\`: 
+        "src/index.gts:14:5 - error TS0: Unclosed element \`p\`: 
 
         |
         |  <p>
@@ -90,7 +89,7 @@ describe('CLI: single-pass build mode typechecking', () => {
 
         (error occurred in 'an unknown module' @ line 4 : column 4)
 
-        15     <p>Unclosed tag.
+        14     <p>Unclosed tag.
                
         "
       `);
@@ -100,7 +99,6 @@ describe('CLI: single-pass build mode typechecking', () => {
       let code = stripIndent`
         import '@glint/environment-ember-template-imports';
         import Component from '@glimmer/component';
-        import { hbs } from 'ember-template-imports';
 
         type ApplicationArgs = {
           version: string;
@@ -112,23 +110,23 @@ describe('CLI: single-pass build mode typechecking', () => {
         export default class Application extends Component<{ Args: ApplicationArgs }> {
           private startupTime = new Date().toISOString();
 
-          public static template = hbs\`
+          <template>
             Welcome to app v{{@version}}.
             The current time is {{truncate this.startupTime 12}}.
-          \`;
+          </template>
         }
       `;
 
-      project.write(INPUT_SCRIPT, code);
+      project.write(INPUT_SFC, code);
 
       let checkResult = await project.build({ reject: false });
 
       expect(checkResult.exitCode).toBe(1);
       expect(checkResult.stdout).toEqual('');
       expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-        "src/index.ts:17:36 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
+        "src/index.gts:16:36 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
 
-        17     The current time is {{truncate this.startupTime 12}}.
+        16     The current time is {{truncate this.startupTime 12}}.
                                               ~~~~~~~~~~~~~~~~
         "
       `);
@@ -175,7 +173,6 @@ describe('CLI: single-pass build mode typechecking', () => {
       beforeEach(async () => {
         let rootCode = stripIndent`
           import Component from '@glimmer/component';
-          import { hbs } from 'ember-template-imports';
           import A from '@glint-test/a';
           import B from '@glint-test/b';
 
@@ -186,10 +183,10 @@ describe('CLI: single-pass build mode typechecking', () => {
           export default class Application extends Component<{ Args: ApplicationArgs }> {
             private startupTime = new Date().toISOString();
 
-            public static template = hbs\`
+            <template>
               Welcome to app v{{@version}}.
               The current time is {{this.startupTime}}.
-            \`;
+            </template>
           }
         `;
 
@@ -209,10 +206,10 @@ describe('CLI: single-pass build mode typechecking', () => {
           export default C;
         `;
 
-        projects.main.write(INPUT_SCRIPT, rootCode);
-        projects.children.a.write(INPUT_SCRIPT, aCode);
-        projects.children.b.write(INPUT_SCRIPT, bCode);
-        projects.children.c.write(INPUT_SCRIPT, cCode);
+        projects.main.write(INPUT_SFC, rootCode);
+        projects.children.a.write(INPUT_SFC, aCode);
+        projects.children.b.write(INPUT_SFC, bCode);
+        projects.children.c.write(INPUT_SFC, cCode);
       });
 
       test('passes a valid composite project', async () => {
@@ -271,15 +268,14 @@ describe('CLI: single-pass build mode typechecking', () => {
             export default C;
           `;
 
-          projects.children.a.write(INPUT_SCRIPT, aCode);
-          projects.children.b.write(INPUT_SCRIPT, bCode);
-          projects.children.c.write(INPUT_SCRIPT, cCode);
+          projects.children.a.write(INPUT_SFC, aCode);
+          projects.children.b.write(INPUT_SFC, bCode);
+          projects.children.c.write(INPUT_SFC, cCode);
         });
 
         test('for invalid TS', async () => {
           let rootCode = stripIndent`
             import Component from '@glimmer/component';
-            import { hbs } from 'ember-template-imports';
             import A from '@glint-test/a';
             import B from '@glint-test/b';
 
@@ -292,23 +288,23 @@ describe('CLI: single-pass build mode typechecking', () => {
             export default class Application extends Component<{ Args: ApplicationArgs }> {
               private startupTime = new Date().toISOString();
 
-              public static template = hbs\`
+              <template>
                 Welcome to app v{{@version}}.
                 The current time is {{this.startupTime}}.
                 {{A}}, {{B}}
-              \`;
+              </template>
             }
           `;
 
-          projects.main.write(INPUT_SCRIPT, rootCode);
+          projects.main.write(INPUT_SFC, rootCode);
 
           let checkResult = await projects.main.build({ reject: false });
           expect(checkResult.exitCode).toBe(2);
           expect(checkResult.stdout).toEqual('');
           expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-            "src/index.ts:6:5 - error TS2322: Type 'number' is not assignable to type 'string'.
+            "src/index.gts:5:5 - error TS2322: Type 'number' is not assignable to type 'string'.
 
-            6 let x: string = 123;
+            5 let x: string = 123;
                   ~
             "
           `);
@@ -321,7 +317,6 @@ describe('CLI: single-pass build mode typechecking', () => {
         test('for invalid template syntax', async () => {
           let rootCode = stripIndent`
             import Component from '@glimmer/component';
-            import { hbs } from 'ember-template-imports';
             import A from '@glint-test/a';
             import B from '@glint-test/b';
 
@@ -332,21 +327,21 @@ describe('CLI: single-pass build mode typechecking', () => {
             export default class Application extends Component<{ Args: ApplicationArgs }> {
               private startupTime = new Date().toISOString();
 
-              public static template = hbs\`
+              <template>
                 Welcome to app v{{@version}}.
                 The current time is {{this.startupTime}}.
                 <p>Unclosed!
-              \`;
+              </template>
             }
           `;
 
-          projects.main.write(INPUT_SCRIPT, rootCode);
+          projects.main.write(INPUT_SFC, rootCode);
 
           let checkResult = await projects.main.build({ reject: false });
           expect(checkResult.exitCode).toBe(2);
           expect(checkResult.stdout).toEqual('');
           expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-            "src/index.ts:16:5 - error TS0: Unclosed element \`p\`: 
+            "src/index.gts:15:5 - error TS0: Unclosed element \`p\`: 
 
             |
             |  <p>
@@ -354,7 +349,7 @@ describe('CLI: single-pass build mode typechecking', () => {
 
             (error occurred in 'an unknown module' @ line 4 : column 4)
 
-            16     <p>Unclosed!
+            15     <p>Unclosed!
                    
             "
           `);
@@ -368,7 +363,6 @@ describe('CLI: single-pass build mode typechecking', () => {
         test('for a template type error', async () => {
           let rootCode = stripIndent`
             import Component from '@glimmer/component';
-            import { hbs } from 'ember-template-imports';
             import A from '@glint-test/a';
             import B from '@glint-test/b';
 
@@ -381,23 +375,23 @@ describe('CLI: single-pass build mode typechecking', () => {
             export default class Application extends Component<{ Args: ApplicationArgs }> {
               private startupTime = new Date().toISOString();
 
-              public static template = hbs\`
+              <template>
                 Welcome to app v{{@version}}.
                 The current time is {{this.startupTime}}.
                 {{double A}}
-              \`;
+              </template>
             }
           `;
 
-          projects.main.write(INPUT_SCRIPT, rootCode);
+          projects.main.write(INPUT_SFC, rootCode);
 
           let checkResult = await projects.main.build({ reject: false });
           expect(checkResult.exitCode).toBe(2);
           expect(checkResult.stdout).toEqual('');
           expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-            "src/index.ts:18:14 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
+            "src/index.gts:17:14 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
 
-            18     {{double A}}
+            17     {{double A}}
                             ~
             "
           `);
@@ -413,7 +407,6 @@ describe('CLI: single-pass build mode typechecking', () => {
         beforeEach(async () => {
           let rootCode = stripIndent`
             import Component from '@glimmer/component';
-            import { hbs } from 'ember-template-imports';
             import A from '@glint-test/a';
             import B from '@glint-test/b';
 
@@ -424,10 +417,10 @@ describe('CLI: single-pass build mode typechecking', () => {
             export default class Application extends Component<{ Args: ApplicationArgs }> {
               private startupTime = new Date().toISOString();
 
-              public static template = hbs\`
+              <template>
                 Welcome to app v{{@version}}.
                 The current time is {{this.startupTime}}.
-              \`;
+              </template>
             }
           `;
 
@@ -441,9 +434,9 @@ describe('CLI: single-pass build mode typechecking', () => {
             export default C;
           `;
 
-          projects.main.write(INPUT_SCRIPT, rootCode);
-          projects.children.b.write(INPUT_SCRIPT, bCode);
-          projects.children.c.write(INPUT_SCRIPT, cCode);
+          projects.main.write(INPUT_SFC, rootCode);
+          projects.children.b.write(INPUT_SFC, bCode);
+          projects.children.c.write(INPUT_SFC, cCode);
         });
 
         describe('for invalid TS', () => {
@@ -454,7 +447,7 @@ describe('CLI: single-pass build mode typechecking', () => {
               export default A;
             `;
 
-            projects.children.a.write(INPUT_SCRIPT, aCode);
+            projects.children.a.write(INPUT_SFC, aCode);
           });
 
           test('build from the main project', async () => {
@@ -463,7 +456,7 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(2);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "../a/src/index.ts:2:15 - error TS2363: The right-hand side of an arithmetic operation must be of type 'any', 'number', 'bigint' or an enum type.
+              "../a/src/index.gts:2:15 - error TS2363: The right-hand side of an arithmetic operation must be of type 'any', 'number', 'bigint' or an enum type.
 
               2 const A = 2 * C;
                               ~
@@ -481,7 +474,7 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(2);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "src/index.ts:2:15 - error TS2363: The right-hand side of an arithmetic operation must be of type 'any', 'number', 'bigint' or an enum type.
+              "src/index.gts:2:15 - error TS2363: The right-hand side of an arithmetic operation must be of type 'any', 'number', 'bigint' or an enum type.
 
               2 const A = 2 * C;
                               ~
@@ -498,13 +491,12 @@ describe('CLI: single-pass build mode typechecking', () => {
           beforeEach(async () => {
             let aCode = stripIndent`
               import C from '@glint-test/c';
-              import { hbs } from 'ember-template-imports';
 
-              const A = hbs\`{{C}\`;
+              const A = <template>{{C}</template>;
               export default A;
             `;
 
-            projects.children.a.write(INPUT_SCRIPT, aCode);
+            projects.children.a.write(INPUT_SFC, aCode);
           });
 
           test('build from the main project', async () => {
@@ -513,13 +505,13 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(2);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "../a/src/index.ts:4:17 - error TS0: Parse error on line 1:
+              "../a/src/index.gts:3:23 - error TS0: Parse error on line 1:
               {{C}
               ---^
               Expecting 'CLOSE_RAW_BLOCK', 'CLOSE', 'CLOSE_UNESCAPED', 'OPEN_SEXPR', 'CLOSE_SEXPR', 'ID', 'OPEN_BLOCK_PARAMS', 'STRING', 'NUMBER', 'BOOLEAN', 'UNDEFINED', 'NULL', 'DATA', 'SEP', got 'INVALID'
 
-              4 const A = hbs\`{{C}\`;
-                                ~
+              3 const A = <template>{{C}</template>;
+                                      ~
               "
             `);
 
@@ -534,13 +526,13 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(2);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "src/index.ts:4:17 - error TS0: Parse error on line 1:
+              "src/index.gts:3:23 - error TS0: Parse error on line 1:
               {{C}
               ---^
               Expecting 'CLOSE_RAW_BLOCK', 'CLOSE', 'CLOSE_UNESCAPED', 'OPEN_SEXPR', 'CLOSE_SEXPR', 'ID', 'OPEN_BLOCK_PARAMS', 'STRING', 'NUMBER', 'BOOLEAN', 'UNDEFINED', 'NULL', 'DATA', 'SEP', got 'INVALID'
 
-              4 const A = hbs\`{{C}\`;
-                                ~
+              3 const A = <template>{{C}</template>;
+                                      ~
               "
             `);
 
@@ -554,14 +546,13 @@ describe('CLI: single-pass build mode typechecking', () => {
           beforeEach(async () => {
             let aCode = stripIndent`
               import C from '@glint-test/c';
-              import { hbs } from 'ember-template-imports';
 
               const double = (n: number): number => n * 2;
-              const A = hbs\`{{double C}}\`;
+              const A = <template>{{double C}}</template>;
               export default A;
             `;
 
-            projects.children.a.write(INPUT_SCRIPT, aCode);
+            projects.children.a.write(INPUT_SFC, aCode);
           });
 
           test('build from the main project', async () => {
@@ -570,10 +561,10 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(2);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "../a/src/index.ts:5:24 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
+              "../a/src/index.gts:4:30 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
 
-              5 const A = hbs\`{{double C}}\`;
-                                       ~
+              4 const A = <template>{{double C}}</template>;
+                                             ~
               "
             `);
 
@@ -588,10 +579,10 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(2);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "src/index.ts:5:24 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
+              "src/index.gts:4:30 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
 
-              5 const A = hbs\`{{double C}}\`;
-                                       ~
+              4 const A = <template>{{double C}}</template>;
+                                             ~
               "
             `);
 
@@ -606,7 +597,6 @@ describe('CLI: single-pass build mode typechecking', () => {
         beforeEach(async () => {
           let rootCode = stripIndent`
             import Component from '@glimmer/component';
-            import { hbs } from 'ember-template-imports';
             import A from '@glint-test/a';
             import B from '@glint-test/b';
 
@@ -617,10 +607,10 @@ describe('CLI: single-pass build mode typechecking', () => {
             export default class Application extends Component<{ Args: ApplicationArgs }> {
               private startupTime = new Date().toISOString();
 
-              public static template = hbs\`
+              <template>
                 Welcome to app v{{@version}}.
                 The current time is {{this.startupTime}}.
-              \`;
+              </template>
             }
           `;
 
@@ -635,9 +625,9 @@ describe('CLI: single-pass build mode typechecking', () => {
             export default C;
           `;
 
-          projects.main.write(INPUT_SCRIPT, rootCode);
-          projects.children.a.write(INPUT_SCRIPT, aCode);
-          projects.children.c.write(INPUT_SCRIPT, cCode);
+          projects.main.write(INPUT_SFC, rootCode);
+          projects.children.a.write(INPUT_SFC, aCode);
+          projects.children.c.write(INPUT_SFC, cCode);
         });
 
         describe('for invalid TS', () => {
@@ -647,7 +637,7 @@ describe('CLI: single-pass build mode typechecking', () => {
               export default B;
             `;
 
-            projects.children.b.write(INPUT_SCRIPT, bCode);
+            projects.children.b.write(INPUT_SFC, bCode);
           });
 
           test('build from the main project', async () => {
@@ -656,7 +646,7 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(2);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "../b/src/index.ts:1:7 - error TS2322: Type 'string' is not assignable to type 'number'.
+              "../b/src/index.gts:1:7 - error TS2322: Type 'string' is not assignable to type 'number'.
 
               1 const B: number = 'ahoy';
                       ~
@@ -674,7 +664,7 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(1);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "src/index.ts:1:7 - error TS2322: Type 'string' is not assignable to type 'number'.
+              "src/index.gts:1:7 - error TS2322: Type 'string' is not assignable to type 'number'.
 
               1 const B: number = 'ahoy';
                       ~
@@ -690,13 +680,12 @@ describe('CLI: single-pass build mode typechecking', () => {
         describe('for invalid template syntax', () => {
           beforeEach(async () => {
             let bCode = stripIndent`
-              import { hbs } from 'ember-template-imports';
-              const usage = hbs\`{{123}\`;
+              const usage = <template>{{123}</template>;
               const B = 'ahoy';
               export default B;
             `;
 
-            projects.children.b.write(INPUT_SCRIPT, bCode);
+            projects.children.b.write(INPUT_SFC, bCode);
           });
 
           test('build from the main project', async () => {
@@ -705,13 +694,13 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(2);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "../b/src/index.ts:2:21 - error TS0: Parse error on line 1:
+              "../b/src/index.gts:1:27 - error TS0: Parse error on line 1:
               {{123}
               -----^
               Expecting 'CLOSE_RAW_BLOCK', 'CLOSE', 'CLOSE_UNESCAPED', 'OPEN_SEXPR', 'CLOSE_SEXPR', 'ID', 'OPEN_BLOCK_PARAMS', 'STRING', 'NUMBER', 'BOOLEAN', 'UNDEFINED', 'NULL', 'DATA', got 'INVALID'
 
-              2 const usage = hbs\`{{123}\`;
-                                    ~~~
+              1 const usage = <template>{{123}</template>;
+                                          ~~~
               "
             `);
 
@@ -726,13 +715,13 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(1);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "src/index.ts:2:21 - error TS0: Parse error on line 1:
+              "src/index.gts:1:27 - error TS0: Parse error on line 1:
               {{123}
               -----^
               Expecting 'CLOSE_RAW_BLOCK', 'CLOSE', 'CLOSE_UNESCAPED', 'OPEN_SEXPR', 'CLOSE_SEXPR', 'ID', 'OPEN_BLOCK_PARAMS', 'STRING', 'NUMBER', 'BOOLEAN', 'UNDEFINED', 'NULL', 'DATA', got 'INVALID'
 
-              2 const usage = hbs\`{{123}\`;
-                                    ~~~
+              1 const usage = <template>{{123}</template>;
+                                          ~~~
               "
             `);
 
@@ -745,14 +734,13 @@ describe('CLI: single-pass build mode typechecking', () => {
         describe('for a template type error', () => {
           beforeEach(async () => {
             let bCode = stripIndent`
-              import { hbs } from 'ember-template-imports';
               const double = (n: number) => n * 2;
-              const Usage = hbs\`{{double "hello"}}\`;
+              const Usage = <template>{{double "hello"}}</template>;
               const B = 'ahoy';
               export default B;
             `;
 
-            projects.children.b.write(INPUT_SCRIPT, bCode);
+            projects.children.b.write(INPUT_SFC, bCode);
           });
 
           test('build from the main project', async () => {
@@ -761,10 +749,10 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(2);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "../b/src/index.ts:3:28 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
+              "../b/src/index.gts:2:34 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
 
-              3 const Usage = hbs\`{{double \\"hello\\"}}\`;
-                                           ~~~~~~~
+              2 const Usage = <template>{{double \\"hello\\"}}</template>;
+                                                 ~~~~~~~
               "
             `);
 
@@ -779,10 +767,10 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(1);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "src/index.ts:3:28 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
+              "src/index.gts:2:34 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
 
-              3 const Usage = hbs\`{{double \\"hello\\"}}\`;
-                                           ~~~~~~~
+              2 const Usage = <template>{{double \\"hello\\"}}</template>;
+                                                 ~~~~~~~
               "
             `);
 
@@ -797,7 +785,6 @@ describe('CLI: single-pass build mode typechecking', () => {
         beforeEach(() => {
           let rootCode = stripIndent`
             import Component from '@glimmer/component';
-            import { hbs } from 'ember-template-imports';
             import A from '@glint-test/a';
             import B from '@glint-test/b';
 
@@ -808,10 +795,10 @@ describe('CLI: single-pass build mode typechecking', () => {
             export default class Application extends Component<{ Args: ApplicationArgs }> {
               private startupTime = new Date().toISOString();
 
-              public static template = hbs\`
+              <template>
                 Welcome to app v{{@version}}.
                 The current time is {{this.startupTime}}.
-              \`;
+              </template>
             }
           `;
 
@@ -826,9 +813,9 @@ describe('CLI: single-pass build mode typechecking', () => {
             export default B;
           `;
 
-          projects.main.write(INPUT_SCRIPT, rootCode);
-          projects.children.a.write(INPUT_SCRIPT, aCode);
-          projects.children.b.write(INPUT_SCRIPT, bCode);
+          projects.main.write(INPUT_SFC, rootCode);
+          projects.children.a.write(INPUT_SFC, aCode);
+          projects.children.b.write(INPUT_SFC, bCode);
         });
 
         describe('for invalid TS', () => {
@@ -837,7 +824,7 @@ describe('CLI: single-pass build mode typechecking', () => {
               const C: number = 'world';
               export default C;
             `;
-            projects.children.c.write(INPUT_SCRIPT, cCode);
+            projects.children.c.write(INPUT_SFC, cCode);
           });
 
           test('built from the main project', async () => {
@@ -846,7 +833,7 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(2);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "../c/src/index.ts:1:7 - error TS2322: Type 'string' is not assignable to type 'number'.
+              "../c/src/index.gts:1:7 - error TS2322: Type 'string' is not assignable to type 'number'.
 
               1 const C: number = 'world';
                       ~
@@ -864,7 +851,7 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(1);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "../c/src/index.ts:1:7 - error TS2322: Type 'string' is not assignable to type 'number'.
+              "../c/src/index.gts:1:7 - error TS2322: Type 'string' is not assignable to type 'number'.
 
               1 const C: number = 'world';
                       ~
@@ -882,7 +869,7 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(1);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "src/index.ts:1:7 - error TS2322: Type 'string' is not assignable to type 'number'.
+              "src/index.gts:1:7 - error TS2322: Type 'string' is not assignable to type 'number'.
 
               1 const C: number = 'world';
                       ~
@@ -898,13 +885,12 @@ describe('CLI: single-pass build mode typechecking', () => {
         describe('for invalid template syntax', () => {
           beforeEach(() => {
             let cCode = stripIndent`
-              import { hbs } from 'ember-template-imports';
-              const Bad = hbs\`{{123}\`;
+              const Bad = <template>{{123}</template>;
               const C = 'world';
               export default C;
             `;
 
-            projects.children.c.write(INPUT_SCRIPT, cCode);
+            projects.children.c.write(INPUT_SFC, cCode);
           });
 
           test('built from the main project', async () => {
@@ -913,13 +899,13 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(2);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "../c/src/index.ts:2:19 - error TS0: Parse error on line 1:
+              "../c/src/index.gts:1:25 - error TS0: Parse error on line 1:
               {{123}
               -----^
               Expecting 'CLOSE_RAW_BLOCK', 'CLOSE', 'CLOSE_UNESCAPED', 'OPEN_SEXPR', 'CLOSE_SEXPR', 'ID', 'OPEN_BLOCK_PARAMS', 'STRING', 'NUMBER', 'BOOLEAN', 'UNDEFINED', 'NULL', 'DATA', got 'INVALID'
 
-              2 const Bad = hbs\`{{123}\`;
-                                  ~~~
+              1 const Bad = <template>{{123}</template>;
+                                        ~~~
               "
             `);
 
@@ -934,13 +920,13 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(1);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "../c/src/index.ts:2:19 - error TS0: Parse error on line 1:
+              "../c/src/index.gts:1:25 - error TS0: Parse error on line 1:
               {{123}
               -----^
               Expecting 'CLOSE_RAW_BLOCK', 'CLOSE', 'CLOSE_UNESCAPED', 'OPEN_SEXPR', 'CLOSE_SEXPR', 'ID', 'OPEN_BLOCK_PARAMS', 'STRING', 'NUMBER', 'BOOLEAN', 'UNDEFINED', 'NULL', 'DATA', got 'INVALID'
 
-              2 const Bad = hbs\`{{123}\`;
-                                  ~~~
+              1 const Bad = <template>{{123}</template>;
+                                        ~~~
               "
             `);
 
@@ -955,13 +941,13 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(1);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "src/index.ts:2:19 - error TS0: Parse error on line 1:
+              "src/index.gts:1:25 - error TS0: Parse error on line 1:
               {{123}
               -----^
               Expecting 'CLOSE_RAW_BLOCK', 'CLOSE', 'CLOSE_UNESCAPED', 'OPEN_SEXPR', 'CLOSE_SEXPR', 'ID', 'OPEN_BLOCK_PARAMS', 'STRING', 'NUMBER', 'BOOLEAN', 'UNDEFINED', 'NULL', 'DATA', got 'INVALID'
 
-              2 const Bad = hbs\`{{123}\`;
-                                  ~~~
+              1 const Bad = <template>{{123}</template>;
+                                        ~~~
               "
             `);
 
@@ -974,14 +960,13 @@ describe('CLI: single-pass build mode typechecking', () => {
         describe('for a template type error', () => {
           beforeEach(() => {
             let cCode = stripIndent`
-              import { hbs } from 'ember-template-imports';
               const double = (n: number) => n * 2;
-              const useDouble = hbs\`{{double "hello"}}\`;
+              const useDouble = <template>{{double "hello"}}</template>;
               const C = 'world';
               export default C;
             `;
 
-            projects.children.c.write(INPUT_SCRIPT, cCode);
+            projects.children.c.write(INPUT_SFC, cCode);
           });
 
           test('built from the main project', async () => {
@@ -990,10 +975,10 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(2);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "../c/src/index.ts:3:32 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
+              "../c/src/index.gts:2:38 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
 
-              3 const useDouble = hbs\`{{double \\"hello\\"}}\`;
-                                               ~~~~~~~
+              2 const useDouble = <template>{{double \\"hello\\"}}</template>;
+                                                     ~~~~~~~
               "
             `);
 
@@ -1008,10 +993,10 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(1);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "../c/src/index.ts:3:32 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
+              "../c/src/index.gts:2:38 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
 
-              3 const useDouble = hbs\`{{double \\"hello\\"}}\`;
-                                               ~~~~~~~
+              2 const useDouble = <template>{{double \\"hello\\"}}</template>;
+                                                     ~~~~~~~
               "
             `);
 
@@ -1026,10 +1011,10 @@ describe('CLI: single-pass build mode typechecking', () => {
             expect(checkResult.exitCode).toBe(1);
             expect(checkResult.stdout).toEqual('');
             expect(stripAnsi(checkResult.stderr)).toMatchInlineSnapshot(`
-              "src/index.ts:3:32 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
+              "src/index.gts:2:38 - error TS2345: Argument of type 'string' is not assignable to parameter of type 'number'.
 
-              3 const useDouble = hbs\`{{double \\"hello\\"}}\`;
-                                               ~~~~~~~
+              2 const useDouble = <template>{{double \\"hello\\"}}</template>;
+                                                     ~~~~~~~
               "
             `);
 
@@ -1068,7 +1053,6 @@ describe('CLI: --build --clean', () => {
     let code = stripIndent`
       import '@glint/environment-ember-template-imports';
       import Component from '@glimmer/component';
-      import { hbs } from 'ember-template-imports';
 
       type ApplicationArgs = {
         version: string;
@@ -1077,14 +1061,14 @@ describe('CLI: --build --clean', () => {
       export default class Application extends Component<{ Args: ApplicationArgs }> {
         private startupTime = new Date().toISOString();
 
-        public static template = hbs\`
+        <template>
           Welcome to app v{{@version}}.
           The current time is {{this.startupTime}}.
-        \`;
+        </template>
       }
     `;
 
-    project.write(INPUT_SCRIPT, code);
+    project.write(INPUT_SFC, code);
 
     let buildResult = await project.build();
     expect(buildResult.exitCode).toBe(0);
@@ -1100,7 +1084,6 @@ describe('CLI: --build --clean', () => {
 
     let rootCode = stripIndent`
       import Component from '@glimmer/component';
-      import { hbs } from 'ember-template-imports';
       import A from '@glint-test/a';
       import B from '@glint-test/b';
 
@@ -1111,10 +1094,10 @@ describe('CLI: --build --clean', () => {
       export default class Application extends Component<{ Args: ApplicationArgs }> {
         private startupTime = new Date().toISOString();
 
-        public static template = hbs\`
+        <template>
           Welcome to app v{{@version}}.
           The current time is {{this.startupTime}}.
-        \`;
+        </template>
       }
     `;
 
@@ -1134,10 +1117,10 @@ describe('CLI: --build --clean', () => {
       export default C;
     `;
 
-    projects.main.write(INPUT_SCRIPT, rootCode);
-    projects.children.a.write(INPUT_SCRIPT, aCode);
-    projects.children.b.write(INPUT_SCRIPT, bCode);
-    projects.children.c.write(INPUT_SCRIPT, cCode);
+    projects.main.write(INPUT_SFC, rootCode);
+    projects.children.a.write(INPUT_SFC, aCode);
+    projects.children.b.write(INPUT_SFC, bCode);
+    projects.children.c.write(INPUT_SFC, cCode);
 
     let buildResult = await projects.main.build();
     expect(buildResult.exitCode).toBe(0);
@@ -1164,7 +1147,6 @@ describe('CLI: --build --force', () => {
     let code = stripIndent`
       import '@glint/environment-ember-template-imports';
       import Component from '@glimmer/component';
-      import { hbs } from 'ember-template-imports';
 
       type ApplicationArgs = {
         version: string;
@@ -1173,14 +1155,14 @@ describe('CLI: --build --force', () => {
       export default class Application extends Component<{ Args: ApplicationArgs }> {
         private startupTime = new Date().toISOString();
 
-        public static template = hbs\`
+        <template>
           Welcome to app v{{@version}}.
           The current time is {{this.startupTime}}.
-        \`;
+        </template>
       }
     `;
 
-    project.write(INPUT_SCRIPT, code);
+    project.write(INPUT_SFC, code);
 
     let buildResult = await project.build();
     expect(buildResult.exitCode).toBe(0);
@@ -1202,7 +1184,6 @@ describe('CLI: --build --force', () => {
 
     let rootCode = stripIndent`
       import Component from '@glimmer/component';
-      import { hbs } from 'ember-template-imports';
       import A from '@glint-test/a';
       import B from '@glint-test/b';
 
@@ -1213,10 +1194,10 @@ describe('CLI: --build --force', () => {
       export default class Application extends Component<{ Args: ApplicationArgs }> {
         private startupTime = new Date().toISOString();
 
-        public static template = hbs\`
+        <template>
           Welcome to app v{{@version}}.
           The current time is {{this.startupTime}}.
-        \`;
+        </template>
       }
     `;
 
@@ -1236,10 +1217,10 @@ describe('CLI: --build --force', () => {
       export default C;
     `;
 
-    projects.main.write(INPUT_SCRIPT, rootCode);
-    projects.children.a.write(INPUT_SCRIPT, aCode);
-    projects.children.b.write(INPUT_SCRIPT, bCode);
-    projects.children.c.write(INPUT_SCRIPT, cCode);
+    projects.main.write(INPUT_SFC, rootCode);
+    projects.children.a.write(INPUT_SFC, aCode);
+    projects.children.b.write(INPUT_SFC, bCode);
+    projects.children.c.write(INPUT_SFC, cCode);
 
     let buildResult = await projects.main.build();
     expect(buildResult.exitCode).toBe(0);
@@ -1280,7 +1261,6 @@ describe('CLI: --build --dry', () => {
       let code = stripIndent`
         import '@glint/environment-ember-template-imports';
         import Component from '@glimmer/component';
-        import { hbs } from 'ember-template-imports';
 
         type ApplicationArgs = {
           version: string;
@@ -1289,14 +1269,14 @@ describe('CLI: --build --dry', () => {
         export default class Application extends Component<{ Args: ApplicationArgs }> {
           private startupTime = new Date().toISOString();
 
-          public static template = hbs\`
+          <template>
             Welcome to app v{{@version}}.
             The current time is {{this.startupTime}}.
-          \`;
+          </template>
         }
       `;
 
-      project.write(INPUT_SCRIPT, code);
+      project.write(INPUT_SFC, code);
     });
 
     test('when no build has occurred', async () => {
@@ -1326,7 +1306,6 @@ describe('CLI: --build --dry', () => {
         let code = stripIndent`
           import '@glint/environment-ember-template-imports';
           import Component from '@glimmer/component';
-          import { hbs } from 'ember-template-imports';
 
           type ApplicationArgs = {
             appVersion: string;
@@ -1335,14 +1314,14 @@ describe('CLI: --build --dry', () => {
           export default class Application extends Component<{ Args: ApplicationArgs }> {
             private startupTime = new Date().toISOString();
 
-            public static template = hbs\`
+            <template>
               Welcome to app v{{@appVersion}}.
               The current time is {{this.startupTime}}.
-            \`;
+            </template>
           }
         `;
 
-        project.write(INPUT_SCRIPT, code);
+        project.write(INPUT_SFC, code);
 
         let buildResult = await project.build({ flags: ['--dry'] });
         expect(buildResult.exitCode).toBe(0);
@@ -1365,7 +1344,6 @@ describe('CLI: --build --dry', () => {
       let backingClass = stripIndent`
         import '@glint/environment-ember-template-imports';
         import Component from '@glimmer/component';
-        import { hbs } from 'ember-template-imports';
 
         type ApplicationArgs = {
           version: string;
@@ -1412,7 +1390,6 @@ describe('CLI: --build --dry', () => {
         let backingClass = stripIndent`
           import '@glint/environment-ember-template-imports';
           import Component from '@glimmer/component';
-          import { hbs } from 'ember-template-imports';
 
           type ApplicationArgs = {
             version: string;
@@ -1439,7 +1416,7 @@ describe('CLI: --build --dry', () => {
           The current time is {{this.startupTime}}.
         `;
 
-        project.write(INPUT_SCRIPT, template);
+        project.write(INPUT_TEMPLATE, template);
 
         let buildResult = await project.build({ flags: ['--dry'] });
         expect(buildResult.exitCode).toBe(0);
@@ -1458,7 +1435,6 @@ describe('CLI: --build --dry', () => {
 
       let rootCode = stripIndent`
         import Component from '@glimmer/component';
-        import { hbs } from 'ember-template-imports';
         import A from '@glint-test/a';
         import B from '@glint-test/b';
 
@@ -1469,10 +1445,10 @@ describe('CLI: --build --dry', () => {
         export default class Application extends Component<{ Args: ApplicationArgs }> {
           private startupTime = new Date().toISOString();
 
-          public static template = hbs\`
+          <template>
             Welcome to app v{{@version}}.
             The current time is {{this.startupTime}}.
-          \`;
+          </template>
         }
       `;
 
@@ -1492,10 +1468,10 @@ describe('CLI: --build --dry', () => {
         export default C;
       `;
 
-      projects.main.write(INPUT_SCRIPT, rootCode);
-      projects.children.a.write(INPUT_SCRIPT, aCode);
-      projects.children.b.write(INPUT_SCRIPT, bCode);
-      projects.children.c.write(INPUT_SCRIPT, cCode);
+      projects.main.write(INPUT_SFC, rootCode);
+      projects.children.a.write(INPUT_SFC, aCode);
+      projects.children.b.write(INPUT_SFC, bCode);
+      projects.children.c.write(INPUT_SFC, cCode);
     });
 
     test('when no build has occurred', async () => {
@@ -1543,7 +1519,6 @@ describe('CLI: --build --dry', () => {
         test('in a project which has changed with direct references which have not changed', async () => {
           let rootCode = stripIndent`
             import Component from '@glimmer/component';
-            import { hbs } from 'ember-template-imports';
             import A from '@glint-test/a';
             import B from '@glint-test/b';
 
@@ -1554,13 +1529,13 @@ describe('CLI: --build --dry', () => {
             export default class Application extends Component<{ Args: ApplicationArgs }> {
               private startupTime = new Date().toISOString();
 
-              public static template = hbs\`
+              <template>
                 Welcome to app v{{@appVersion}}.
                 The current time is {{this.startupTime}}.
-              \`;
+              </template>
             }
           `;
-          projects.main.write(INPUT_SCRIPT, rootCode);
+          projects.main.write(INPUT_SFC, rootCode);
 
           let buildResult = await projects.root.build({ flags: ['--dry'] });
           expect(buildResult.exitCode).toBe(0);
@@ -1585,7 +1560,7 @@ describe('CLI: --build --dry', () => {
             const A = 'hello there, ' + C;
             export default A;
           `;
-          projects.children.a.write(INPUT_SCRIPT, aCode);
+          projects.children.a.write(INPUT_SFC, aCode);
 
           let buildResult = await projects.root.build({ flags: ['--dry'] });
           expect(buildResult.exitCode).toBe(0);
diff --git a/packages/core/__tests__/cli/incremental.test.ts b/packages/core/__tests__/cli/incremental.test.ts
index e6e09f609..209dc2f39 100644
--- a/packages/core/__tests__/cli/incremental.test.ts
+++ b/packages/core/__tests__/cli/incremental.test.ts
@@ -6,16 +6,15 @@ import { beforeEach, describe, expect, test } from 'vitest';
 import { Project } from '@glint/test-utils';
 
 const BUILD_INFO = 'tsconfig.tsbuildinfo';
-const INPUT_SCRIPT = 'index.ts';
+const INPUT_SCRIPT = 'index.gts';
 
 describe('CLI: --incremental', () => {
   test('when no build has occurred', async () => {
-    let project = await Project.create();
+    let project = await Project.create({ glint: { environment: 'ember-template-imports' } });
 
     let code = stripIndent`
       import '@glint/environment-ember-template-imports';
       import Component from '@glimmer/component';
-      import { hbs } from 'ember-template-imports';
 
       type ApplicationArgs = {
         version: string;
@@ -24,10 +23,10 @@ describe('CLI: --incremental', () => {
       export default class Application extends Component<{ Args: ApplicationArgs }> {
         private startupTime = new Date().toISOString();
 
-        public static template = hbs\`
+        <template>
           Welcome to app v{{@version}}.
           The current time is {{this.startupTime}}.
-        \`;
+        </template>
       }
     `;
 
@@ -49,12 +48,11 @@ describe('CLI: --incremental', () => {
   describe('when a build has occurred', () => {
     let project!: Project;
     beforeEach(async () => {
-      project = await Project.create();
+      project = await Project.create({ glint: { environment: 'ember-template-imports' } });
 
       let code = stripIndent`
         import '@glint/environment-ember-template-imports';
         import Component from '@glimmer/component';
-        import { hbs } from 'ember-template-imports';
 
         type ApplicationArgs = {
           version: string;
@@ -63,10 +61,10 @@ describe('CLI: --incremental', () => {
         export default class Application extends Component<{ Args: ApplicationArgs }> {
           private startupTime = new Date().toISOString();
 
-          public static template = hbs\`
+          <template>
             Welcome to app v{{@version}}.
             The current time is {{this.startupTime}}.
-          \`;
+          </template>
         }
       `;
 
@@ -96,7 +94,6 @@ describe('CLI: --incremental', () => {
       let code = stripIndent`
         import '@glint/environment-ember-template-imports';
         import Component from '@glimmer/component';
-        import { hbs } from 'ember-template-imports';
 
         type ApplicationArgs = {
           appVersion: string;
@@ -105,10 +102,10 @@ describe('CLI: --incremental', () => {
         export default class Application extends Component<{ Args: ApplicationArgs }> {
           private startupTime = new Date().toISOString();
 
-          public static template = hbs\`
+          <template>
             Welcome to app v{{@appVersion}}.
             The current time is {{this.startupTime}}.
-          \`;
+          </template>
         }
       `;
 
@@ -135,7 +132,6 @@ describe('CLI: --incremental', () => {
       let code = stripIndent`
         import '@glint/environment-ember-template-imports';
         import Component from '@glimmer/component';
-        import { hbs } from 'ember-template-imports';
   
         type ApplicationArgs = {
           version: string;
@@ -144,10 +140,10 @@ describe('CLI: --incremental', () => {
         export default class Application extends Component<{ Args: ApplicationArgs }> {
           private startupTime = new Date().toISOString();
   
-          public static template = hbs\`
+          <template>
             Welcome to app v{{@version}}.
             The current time is {{this.startupTime}}.
-          \`;
+          </template.
         }
       `;
 
diff --git a/test-packages/test-utils/src/composite-project.ts b/test-packages/test-utils/src/composite-project.ts
index 32d3126d2..f03ac7063 100644
--- a/test-packages/test-utils/src/composite-project.ts
+++ b/test-packages/test-utils/src/composite-project.ts
@@ -4,6 +4,7 @@ import * as path from 'path';
 import { Project } from './project.js';
 
 export const INPUT_DIR = 'src';
+export const INPUT_SFC = path.join(INPUT_DIR, 'index.gts');
 export const INPUT_SCRIPT = path.join(INPUT_DIR, 'index.ts');
 export const INPUT_TEMPLATE = path.join(INPUT_DIR, 'index.hbs');
 

From f7e601460d00ff1f9fe8741240e438a00a984b79 Mon Sep 17 00:00:00 2001
From: Dan Freeman <dfreeman@salsify.com>
Date: Tue, 22 Nov 2022 11:16:59 +0100
Subject: [PATCH 4/6] Fix `--build` for environments with custom extensions

---
 packages/core/src/cli/utils/patch-program.ts  |  2 +-
 .../src/cli/utils/transform-manager-pool.ts   | 23 ++++++++++++-------
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/packages/core/src/cli/utils/patch-program.ts b/packages/core/src/cli/utils/patch-program.ts
index 6edc75562..cc5a983c1 100644
--- a/packages/core/src/cli/utils/patch-program.ts
+++ b/packages/core/src/cli/utils/patch-program.ts
@@ -21,7 +21,7 @@ export function patchProgram(
   if (isPool(transformManagerOrPool)) {
     let configFile = program.getCompilerOptions()['configFilePath'];
     assert(typeof configFile === 'string', 'internal error: missing TS config file');
-    manager = transformManagerOrPool.managerFor(configFile);
+    manager = transformManagerOrPool.managerForFile(configFile);
   } else {
     manager = transformManagerOrPool;
   }
diff --git a/packages/core/src/cli/utils/transform-manager-pool.ts b/packages/core/src/cli/utils/transform-manager-pool.ts
index 6aa24950c..035f0652e 100644
--- a/packages/core/src/cli/utils/transform-manager-pool.ts
+++ b/packages/core/src/cli/utils/transform-manager-pool.ts
@@ -1,3 +1,4 @@
+import { dirname } from 'node:path';
 import * as TS from 'typescript';
 import { ConfigLoader, GlintConfig } from '../../config/index.js';
 import TransformManager from '../../common/transform-manager.js';
@@ -28,8 +29,12 @@ export default class TransformManagerPool {
     this.#rootSys = sys;
   }
 
-  public managerFor(path: string): TransformManager | null {
-    let config = this.#loader.configForFile(path);
+  public managerForFile(path: string): TransformManager | null {
+    return this.managerForDirectory(dirname(path));
+  }
+
+  public managerForDirectory(path: string): TransformManager | null {
+    let config = this.#loader.configForDirectory(path);
     if (!config) return null;
 
     const existing = this.#managers.get(config);
@@ -47,7 +52,8 @@ export default class TransformManagerPool {
     includes: ReadonlyArray<string>,
     depth?: number | undefined
   ): Array<string> => {
-    let readDirectory = this.managerFor(rootDir)?.readDirectory ?? this.#rootSys.readDirectory;
+    let readDirectory =
+      this.managerForDirectory(rootDir)?.readDirectory ?? this.#rootSys.readDirectory;
     return readDirectory(rootDir, extensions, excludes, includes, depth);
   };
 
@@ -58,12 +64,13 @@ export default class TransformManagerPool {
     options?: TS.WatchOptions
   ): TS.FileWatcher => {
     assert(this.#rootSys.watchDirectory);
-    let watchDirectory = this.managerFor(path)?.watchDirectory ?? this.#rootSys.watchDirectory;
+    let watchDirectory =
+      this.managerForDirectory(path)?.watchDirectory ?? this.#rootSys.watchDirectory;
     return watchDirectory(path, originalCallback, recursive, options);
   };
 
   public fileExists = (filename: string): boolean => {
-    let fileExists = this.managerFor(filename)?.fileExists ?? this.#rootSys.fileExists;
+    let fileExists = this.managerForFile(filename)?.fileExists ?? this.#rootSys.fileExists;
     return fileExists(filename);
   };
 
@@ -75,20 +82,20 @@ export default class TransformManagerPool {
   ): TS.FileWatcher => {
     assert(this.#rootSys.watchFile);
     let watchTransformedFile =
-      this.managerFor(path)?.watchTransformedFile ?? this.#rootSys.watchFile;
+      this.managerForFile(path)?.watchTransformedFile ?? this.#rootSys.watchFile;
     return watchTransformedFile(path, originalCallback, pollingInterval, options);
   };
 
   public readTransformedFile = (filename: string, encoding?: string): string | undefined => {
     let readTransformedFile =
-      this.managerFor(filename)?.readTransformedFile ?? this.#rootSys.readFile;
+      this.managerForFile(filename)?.readTransformedFile ?? this.#rootSys.readFile;
     return readTransformedFile(filename, encoding);
   };
 
   public getModifiedTime = (filename: string): Date | undefined => {
     assert(this.#rootSys.getModifiedTime);
     let getModifiedTime =
-      this.managerFor(filename)?.getModifiedTime ?? this.#rootSys.getModifiedTime;
+      this.managerForFile(filename)?.getModifiedTime ?? this.#rootSys.getModifiedTime;
     return getModifiedTime(filename);
   };
 }

From 4da2959cc148cba7b106f9b043abb6ca84035a45 Mon Sep 17 00:00:00 2001
From: Dan Freeman <dfreeman@salsify.com>
Date: Tue, 22 Nov 2022 11:31:35 +0100
Subject: [PATCH 5/6] Transform templates with syntax errors as empty templates

Previously we just left the original source file untouched,
which was fine for embedded tagged strings, but causes
a cascade of syntax errors if we leave `<template>` around.
---
 .../core/__tests__/transform/debug.test.ts    |  8 ++---
 .../core/__tests__/transform/rewrite.test.ts  | 29 ++++++++++++-------
 .../language-server/glint-language-server.ts  |  1 +
 .../template/map-template-contents.ts         | 10 +++----
 .../template/template-to-typescript.ts        | 16 +++++-----
 5 files changed, 36 insertions(+), 28 deletions(-)

diff --git a/packages/core/__tests__/transform/debug.test.ts b/packages/core/__tests__/transform/debug.test.ts
index 35c8a7185..25b6cd362 100644
--- a/packages/core/__tests__/transform/debug.test.ts
+++ b/packages/core/__tests__/transform/debug.test.ts
@@ -205,7 +205,7 @@ describe('Transform: Debug utilities', () => {
         |
         | | Mapping: Template
         | |  hbs(155:200): <HelperComponent @foo={{this.bar}} />
-        | |  ts(324:451):  hbs;\\\\n  {\\\\n    const 𝛄 = χ.emitComponent(χ.resolve(HelperComponent)({ foo: 𝚪.this.bar, ...χ.NamedArgsMarker }));\\\\n    𝛄;\\\\n  }
+        | |  ts(331:451):  {\\\\n    const 𝛄 = χ.emitComponent(χ.resolve(HelperComponent)({ foo: 𝚪.this.bar, ...χ.NamedArgsMarker }));\\\\n    𝛄;\\\\n  }
         | |
         | | | Mapping: TextContent
         | | |  hbs(155:160):
@@ -260,7 +260,7 @@ describe('Transform: Debug utilities', () => {
         |
         | | Mapping: Template
         | |  hbs(299:418): <p ...attributes>\\\\n      Hello, {{@foo}}!\\\\n\\\\n      {{! @glint-expect-error: no @bar arg }}\\\\n      {{@bar}}\\\\n    </p>
-        | |  ts(729:935):  hbs;\\\\n  {\\\\n    const 𝛄 = χ.emitElement(\\"p\\");\\\\n    χ.applySplattributes(𝚪.element, 𝛄.element);\\\\n    χ.emitContent(χ.resolveOrReturn(𝚪.args.foo)());\\\\n    χ.emitContent(χ.resolveOrReturn(𝚪.args.bar)());\\\\n  }
+        | |  ts(736:935):  {\\\\n    const 𝛄 = χ.emitElement(\\"p\\");\\\\n    χ.applySplattributes(𝚪.element, 𝛄.element);\\\\n    χ.emitContent(χ.resolveOrReturn(𝚪.args.foo)());\\\\n    χ.emitContent(χ.resolveOrReturn(𝚪.args.bar)());\\\\n  }
         | |
         | | | Mapping: TextContent
         | | |  hbs(299:304):
@@ -370,7 +370,7 @@ describe('Transform: Debug utilities', () => {
         |
         | | Mapping: Template
         | |  hbs(160:207): <HelperComponent @foo={{this.bar}} />
-        | |  ts(329:456):  hbs;\\\\n  {\\\\n    const 𝛄 = χ.emitComponent(χ.resolve(HelperComponent)({ foo: 𝚪.this.bar, ...χ.NamedArgsMarker }));\\\\n    𝛄;\\\\n  }
+        | |  ts(336:456):  {\\\\n    const 𝛄 = χ.emitComponent(χ.resolve(HelperComponent)({ foo: 𝚪.this.bar, ...χ.NamedArgsMarker }));\\\\n    𝛄;\\\\n  }
         | |
         | | | Mapping: TextContent
         | | |  hbs(160:166):
@@ -425,7 +425,7 @@ describe('Transform: Debug utilities', () => {
         |
         | | Mapping: Template
         | |  hbs(310:436): <p ...attributes>\\\\r\\\\n      Hello, {{@foo}}!\\\\r\\\\n\\\\r\\\\n      {{! @glint-expect-error: no @bar arg }}\\\\r\\\\n      {{@bar}}\\\\r\\\\n    </p>
-        | |  ts(738:944):  hbs;\\\\n  {\\\\n    const 𝛄 = χ.emitElement(\\"p\\");\\\\n    χ.applySplattributes(𝚪.element, 𝛄.element);\\\\n    χ.emitContent(χ.resolveOrReturn(𝚪.args.foo)());\\\\n    χ.emitContent(χ.resolveOrReturn(𝚪.args.bar)());\\\\n  }
+        | |  ts(745:944):  {\\\\n    const 𝛄 = χ.emitElement(\\"p\\");\\\\n    χ.applySplattributes(𝚪.element, 𝛄.element);\\\\n    χ.emitContent(χ.resolveOrReturn(𝚪.args.foo)());\\\\n    χ.emitContent(χ.resolveOrReturn(𝚪.args.bar)());\\\\n  }
         | |
         | | | Mapping: TextContent
         | | |  hbs(310:316):
diff --git a/packages/core/__tests__/transform/rewrite.test.ts b/packages/core/__tests__/transform/rewrite.test.ts
index d90883711..986d7b6b4 100644
--- a/packages/core/__tests__/transform/rewrite.test.ts
+++ b/packages/core/__tests__/transform/rewrite.test.ts
@@ -98,10 +98,15 @@ describe('Transform: rewriteModule', () => {
       let transformedModule = rewriteModule(ts, { script }, glimmerxEnvironment);
 
       expect(transformedModule?.errors.length).toBe(1);
-      expect(transformedModule?.transformedContents).toBe(script.contents);
-
-      expect(transformedModule?.getOriginalOffset(100)).toEqual({ offset: 100, source: script });
-      expect(transformedModule?.getTransformedOffset(script.filename, 100)).toEqual(100);
+      expect(transformedModule?.transformedContents).toMatchInlineSnapshot(`
+        "import Component, { hbs } from '@glimmerx/component';
+        export default class MyComponent extends Component {
+          static template = ({} as typeof import(\\"@glint/environment-glimmerx/-private/dsl\\")).templateForBackingValue(this, function(𝚪, χ: typeof import(\\"@glint/environment-glimmerx/-private/dsl\\")) {
+          hbs;
+          𝚪; χ;
+        });
+        }"
+      `);
     });
 
     test('outer variable capture', () => {
@@ -449,13 +454,15 @@ describe('Transform: rewriteModule', () => {
       let transformedModule = rewriteModule(ts, { script, template }, emberLooseEnvironment);
 
       expect(transformedModule?.errors.length).toBe(1);
-      expect(transformedModule?.transformedContents).toBe(script.contents);
-
-      expect(transformedModule?.getOriginalOffset(50)).toEqual({ offset: 50, source: script });
-      expect(transformedModule?.getTransformedOffset(script.filename, 50)).toEqual(50);
-      expect(transformedModule?.getTransformedOffset(template.filename, 5)).toEqual(
-        script.contents.lastIndexOf('}')
-      );
+      expect(transformedModule?.transformedContents).toMatchInlineSnapshot(`
+        "import Component from '@glimmer/component';
+        export default class MyComponent extends Component {
+        static {
+        ({} as typeof import(\\"@glint/environment-ember-loose/-private/dsl\\")).templateForBackingValue(this, function(𝚪, χ: typeof import(\\"@glint/environment-ember-loose/-private/dsl\\")) {
+          𝚪; χ;
+        })}
+        }"
+      `);
     });
   });
 
diff --git a/packages/core/src/language-server/glint-language-server.ts b/packages/core/src/language-server/glint-language-server.ts
index 329bd4b96..67b0be236 100644
--- a/packages/core/src/language-server/glint-language-server.ts
+++ b/packages/core/src/language-server/glint-language-server.ts
@@ -182,6 +182,7 @@ export default class GlintLanguageServer {
     // we're in a template file, then we have no completions to offer.
     if (
       mapping?.sourceNode.type === 'TextContent' ||
+      mapping?.sourceNode.type === 'TemplateEmbedding' ||
       (!mapping && this.glintConfig.environment.isTemplate(uri))
     ) {
       return;
diff --git a/packages/core/src/transform/template/map-template-contents.ts b/packages/core/src/transform/template/map-template-contents.ts
index c9b2a480e..619bde78b 100644
--- a/packages/core/src/transform/template/map-template-contents.ts
+++ b/packages/core/src/transform/template/map-template-contents.ts
@@ -129,9 +129,10 @@ export type MapTemplateContentsOptions = {
 export function mapTemplateContents(
   template: string,
   { embeddingSyntax }: MapTemplateContentsOptions,
-  callback: (ast: AST.Template, mapper: Mapper) => void
+  callback: (ast: AST.Template | null, mapper: Mapper) => void
 ): RewriteResult {
-  let ast: AST.Template;
+  let ast: AST.Template | null = null;
+  let errors: Array<{ message: string; location: Range | undefined }> = [];
   let lineOffsets = calculateLineOffsets(template, embeddingSyntax.prefix.length);
   try {
     ast = preprocess(template);
@@ -151,9 +152,7 @@ export function mapTemplateContents(
       }
     }
 
-    return {
-      errors: [{ message, location }],
-    };
+    errors.push({ message, location });
   }
 
   let rangeForNode = buildRangeForNode(lineOffsets);
@@ -167,7 +166,6 @@ export function mapTemplateContents(
   let indent = '';
   let offset = 0;
   let needsIndent = false;
-  let errors: Array<{ message: string; location: Range }> = [];
   let directives: Array<LocalDirective> = [];
 
   // Associates all content emitted during the given callback with the
diff --git a/packages/core/src/transform/template/template-to-typescript.ts b/packages/core/src/transform/template/template-to-typescript.ts
index 84457c5c4..51758f85c 100644
--- a/packages/core/src/transform/template/template-to-typescript.ts
+++ b/packages/core/src/transform/template/template-to-typescript.ts
@@ -44,12 +44,7 @@ export function templateToTypescript(
     let scope = new ScopeStack([]);
 
     emitTemplateBoilerplate(() => {
-      for (let line of preamble) {
-        emit.text(line);
-        emit.newline();
-      }
-
-      for (let statement of ast.body) {
+      for (let statement of ast?.body ?? []) {
         emitTopLevelStatement(statement);
       }
     });
@@ -109,7 +104,14 @@ export function templateToTypescript(
       emit.newline();
       emit.indent();
 
-      emit.forNode(ast, emitBody);
+      for (let line of preamble) {
+        emit.text(line);
+        emit.newline();
+      }
+
+      if (ast) {
+        emit.forNode(ast, emitBody);
+      }
 
       // Ensure the context and lib variables are always consumed to prevent
       // an unused variable warning

From bfdb25ecdad53b8c52c8edde8f5938fc4d2ad007 Mon Sep 17 00:00:00 2001
From: Dan Freeman <dfreeman@salsify.com>
Date: Tue, 22 Nov 2022 12:28:36 +0100
Subject: [PATCH 6/6] Ensure `--incremental` works properly with custom file
 extensions

---
 packages/core/src/common/transform-manager.ts | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/packages/core/src/common/transform-manager.ts b/packages/core/src/common/transform-manager.ts
index 4a8ecd71b..f5885533e 100644
--- a/packages/core/src/common/transform-manager.ts
+++ b/packages/core/src/common/transform-manager.ts
@@ -1,4 +1,4 @@
-import { statSync as fsStatSync, Stats } from 'fs';
+import { statSync as fsStatSync, Stats, existsSync } from 'fs';
 import {
   TransformedModule,
   rewriteModule,
@@ -241,10 +241,19 @@ export default class TransformManager {
   };
 
   public getModifiedTime = (filename: string): Date | undefined => {
-    let fileStat = statSync(filename);
+    // In most circumstances we can just ask the DocumentCache what the canonical path
+    // for a given document is, but since `getModifiedTime` is invoked as part of
+    // rehydrating a `.tsbuildinfo` file, typically won't actually know the answer to
+    // that question yet.
+    let canonicalFilename = this.documents
+      .getCandidateDocumentPaths(filename)
+      .find((path) => existsSync(path));
+    if (!canonicalFilename) return undefined;
+
+    let fileStat = statSync(canonicalFilename);
     if (!fileStat) return undefined;
 
-    let companionPath = this.documents.getCompanionDocumentPath(filename);
+    let companionPath = this.documents.getCompanionDocumentPath(canonicalFilename);
     if (!companionPath) return fileStat.mtime;
 
     let companionStat = statSync(companionPath);