From bdf37b4cde5202410c6d8fdaa9665a9ae546e7d1 Mon Sep 17 00:00:00 2001
From: Jon Witting <jon.witting@beacon.io>
Date: Mon, 17 Apr 2023 14:55:33 +0100
Subject: [PATCH] feat: expose `contentBasePublicPath`

---
 index.d.ts            |  6 ++++++
 src/index.js          | 22 ++++++++++++++++------
 test/frames.html      | 28 ++++++++++++++++++++++++++++
 test/rollup.config.js |  1 +
 4 files changed, 51 insertions(+), 6 deletions(-)

diff --git a/index.d.ts b/index.d.ts
index 82a5eb7..1a02438 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -26,6 +26,12 @@ export interface RollupServeOptions {
    */
   contentBase?: string | string[]
 
+  /**
+   * URL path prefix applied to all requests.
+   * E.g. If `contentBasePublicPath="/foo/bar"` and a request is made to `/foo/bar/baz.js`, `baz.js` will be returned from `contentBase`.
+   */
+  contentBasePublicPath?: string
+
   /**
    * Set to `true` to return index.html (200) instead of error page (404)
    * or path to fallback page
diff --git a/src/index.js b/src/index.js
index 58f6ce8..53bdb8f 100644
--- a/src/index.js
+++ b/src/index.js
@@ -17,6 +17,7 @@ function serve (options = { contentBase: '' }) {
     options = { contentBase: options }
   }
   options.contentBase = Array.isArray(options.contentBase) ? options.contentBase : [options.contentBase || '']
+  options.contentBasePublicPath = options.contentBasePublicPath || ''
   options.port = options.port || 10001
   options.headers = options.headers || {}
   options.https = options.https || false
@@ -39,7 +40,7 @@ function serve (options = { contentBase: '' }) {
       response.setHeader(key, options.headers[key])
     })
 
-    readFileFromContentBase(options.contentBase, urlPath, function (error, content, filePath) {
+    readFileFromContentBase(options.contentBase, options.contentBasePublicPath, urlPath, function (error, content, filePath) {
       if (!error) {
         return found(response, filePath, content)
       }
@@ -53,7 +54,7 @@ function serve (options = { contentBase: '' }) {
       }
       if (options.historyApiFallback) {
         const fallbackPath = typeof options.historyApiFallback === 'string' ? options.historyApiFallback : '/index.html'
-        readFileFromContentBase(options.contentBase, fallbackPath, function (error, content, filePath) {
+        readFileFromContentBase(options.contentBase, options.contentBasePublicPath, fallbackPath, function (error, content, filePath) {
           if (error) {
             notFound(response, filePath)
           } else {
@@ -120,18 +121,27 @@ function serve (options = { contentBase: '' }) {
   }
 }
 
-function readFileFromContentBase (contentBase, urlPath, callback) {
-  let filePath = resolve(contentBase[0] || '.', '.' + urlPath)
+function readFileFromContentBase (contentBase, contentBasePublicPath, urlPath, callback) {
+  let internalUrlPath = urlPath
+  if (contentBasePublicPath) {
+    if (urlPath === contentBasePublicPath) {
+      internalUrlPath = '/'
+    } else if (urlPath.startsWith(contentBasePublicPath)) {
+      internalUrlPath = internalUrlPath.replace(contentBasePublicPath, '')
+    }
+  }
+
+  let filePath = resolve(contentBase[0] || '.', '.' + internalUrlPath)
 
   // Load index.html in directories
-  if (urlPath.endsWith('/')) {
+  if (internalUrlPath.endsWith('/')) {
     filePath = resolve(filePath, 'index.html')
   }
 
   readFile(filePath, (error, content) => {
     if (error && contentBase.length > 1) {
       // Try to read from next contentBase
-      readFileFromContentBase(contentBase.slice(1), urlPath, callback)
+      readFileFromContentBase(contentBase.slice(1), contentBasePublicPath, urlPath, callback)
     } else {
       // We know enough
       callback(error, content, filePath)
diff --git a/test/frames.html b/test/frames.html
index 4351cbb..611f0c4 100644
--- a/test/frames.html
+++ b/test/frames.html
@@ -26,16 +26,32 @@
     <td><iframe src="./"></iframe></td>
     <td><iframe src="error.html"></iframe></td>
   </tr>
+  <tr>
+    <td>/foo/bar</td>
+    <td><iframe src="/foo/bar"></iframe></td>
+    <td><iframe src="/foo/bar/"></iframe></td>
+    <td><iframe src="/foo/bar/error.html"></iframe></td>
+  </tr>
   <tr>
     <td>./base1</td>
     <td><iframe src="./base1"></iframe></td>
     <td><iframe src="./base1/"></iframe></td>
   </tr>
+  <tr>
+    <td>/foo/bar/base1</td>
+    <td><iframe src="/foo/bar/base1"></iframe></td>
+    <td><iframe src="/foo/bar/base1/"></iframe></td>
+  </tr>
   <tr>
     <td>./base2</td>
     <td><iframe src="./base2"></iframe></td>
     <td><iframe src="./base2/"></iframe></td>
   </tr>
+  <tr>
+    <td>/foo/bar/base2</td>
+    <td><iframe src="/foo/bar/base2"></iframe></td>
+    <td><iframe src="/foo/bar/base2/"></iframe></td>
+  </tr>
   <tr>
     <th></th>
     <th>./</th>
@@ -48,10 +64,22 @@
     <td><iframe src="./base1/test1.html"></iframe></td>
     <td><iframe src="./base2/test1.html"></iframe></td>
   </tr>
+  <tr>
+    <td>/foo/bar/test1.html</td>
+    <td><iframe src="/foo/bar/test1.html"></iframe></td>
+    <td><iframe src="/foo/bar//base1/test1.html"></iframe></td>
+    <td><iframe src="/foo/bar//base2/test1.html"></iframe></td>
+  </tr>
   <tr>
     <td>test2.html</td>
     <td><iframe src="./test2.html"></iframe></td>
     <td><iframe src="./base1/test2.html"></iframe></td>
     <td><iframe src="./base2/test2.html"></iframe></td>
   </tr>
+  <tr>
+    <td>/foo/bar/test2.html</td>
+    <td><iframe src="/foo/bar//test2.html"></iframe></td>
+    <td><iframe src="/foo/bar//base1/test2.html"></iframe></td>
+    <td><iframe src="/foo/bar//base2/test2.html"></iframe></td>
+  </tr>
 </table>
diff --git a/test/rollup.config.js b/test/rollup.config.js
index 1ba0a4d..dfe0717 100644
--- a/test/rollup.config.js
+++ b/test/rollup.config.js
@@ -28,6 +28,7 @@ export default {
       openPage: '/frames.html',
       historyApiFallback: '/fallback.html',
       contentBase: ['.', 'base1', 'base2'],
+      contentBasePublicPath: '/foo/bar',
       onListening: testOnListening(),
     })
   ]