Store empty RepoConfig when config.toml is absent

src/workflows/repo-config-workflow.test.ts

@@ -56,17 +56,18 @@ describe("RepoConfigWorkflow dispatch — happy path", () => {
 });
 
 describe("RepoConfigWorkflow dispatch — file absent", () => {
-	test("present=false → early return, no DO write, complete", async () => {
+	test("present=false → skips parse, still writes empty settings, complete", async () => {
 		const instanceId = "config_push-repo-missing-delivery-2";
 		await using instance = await introspectWorkflowInstance(
 			env.REPO_CONFIG_WORKFLOW,
 			instanceId,
 		);
 		await instance.modify(async (m) => {
 			await m.mockStepResult({ name: "fetch-config-file" }, { present: false });
-			// parse-and-validate / store-repo-config intentionally NOT mocked — if
-			// the workflow tried to run them unmocked it would fail, exposing a
-			// regression in the early-exit branch.
+			// parse-and-validate intentionally NOT mocked — if the workflow tried
+			// to run it when the file is absent, the unmocked step would fail and
+			// expose a regression in the skip-parse branch.
+			await m.mockStepResult({ name: "store-repo-config" }, { ok: true });
 		});
 		await env.REPO_CONFIG_WORKFLOW.create({ id: instanceId, params: base });
 		await expect(instance.waitForStatus("complete")).resolves.not.toThrow();

src/workflows/steps/sync-repo-config.test.ts

@@ -111,7 +111,7 @@ describe("runSyncRepoConfig", () => {
 		});
 	});
 
-	test("file absent — only runs fetch-config-file and makes no DO writes", async () => {
+	test("file absent — skips parse-and-validate and writes empty settings to DO", async () => {
 		const { step, calls } = makeStep();
 		const { REPO_CONFIG_DO, idFromName, get, setRepoConfig } = makeDO();
 		const github = {
@@ -127,10 +127,18 @@ describe("runSyncRepoConfig", () => {
 			logger: noopLogger,
 		});
 
-		expect(calls.map((c) => c.name)).toEqual(["fetch-config-file"]);
-		expect(idFromName).not.toHaveBeenCalled();
-		expect(get).not.toHaveBeenCalled();
-		expect(setRepoConfig).not.toHaveBeenCalled();
+		expect(calls.map((c) => c.name)).toEqual([
+			"fetch-config-file",
+			"store-repo-config",
+		]);
+		expect(idFromName).toHaveBeenCalledWith("acme/repo");
+		expect(get).toHaveBeenCalledTimes(1);
+		expect(setRepoConfig).toHaveBeenCalledWith({
+			repositoryId: 42,
+			repositoryFullName: "acme/repo",
+			installationId: 100,
+			settings: {},
+		});
 	});
 
 	test("TOML syntax invalid — parse-and-validate throws; store-repo-config not invoked", async () => {

src/workflows/steps/sync-repo-config.ts

@@ -49,30 +49,34 @@ export async function runSyncRepoConfig(
 		return { present: true as const, contentBase64: res.contentBase64 };
 	});
 
-	if (!fileResult.present) {
-		logger.info("No repo config file present; skipping DO write", {
+	let settings: StoredRepoConfig["settings"];
+	if (fileResult.present) {
+		const parseResult = await step.do("parse-and-validate", async () => {
+			const raw = Buffer.from(fileResult.contentBase64, "base64").toString(
+				"utf8",
+			);
+			return { settings: parseRepoConfigToml(raw) };
+		});
+		settings = parseResult.settings;
+	} else {
+		// No config file at head SHA: persist empty settings so downstream
+		// `getRepoConfig()` returns a defaulted `RepoConfig` instead of `null`,
+		// which would otherwise push the task onto the legacy template path.
+		logger.info("No repo config file present; storing empty settings", {
 			fullName,
 			sha: event.head.sha,
 		});
-		return;
+		settings = {};
 	}
 
-	const parseResult = await step.do("parse-and-validate", async () => {
-		const raw = Buffer.from(fileResult.contentBase64, "base64").toString(
-			"utf8",
-		);
-		const settings = parseRepoConfigToml(raw);
-		return { settings };
-	});
-
 	await step.do("store-repo-config", async () => {
 		const id = env.REPO_CONFIG_DO.idFromName(fullName);
 		const stub = env.REPO_CONFIG_DO.get(id);
 		const cfg: StoredRepoConfig = {
 			repositoryId,
 			repositoryFullName: fullName,
 			installationId,
-			settings: parseResult.settings,
+			settings,
 		};
 		await stub.setRepoConfig(cfg);
 		return { ok: true as const };