fix(ci): skip extension lanes with no tests

test/scripts/test-extension.test.ts

@@ -17,6 +17,13 @@ function readPlan(args: string[], cwd = process.cwd()) {
   return JSON.parse(stdout) as ReturnType<typeof resolveExtensionTestPlan>;
 }
 
+function runScript(args: string[], cwd = process.cwd()) {
+  return execFileSync(process.execPath, [scriptPath, ...args], {
+    cwd,
+    encoding: "utf8",
+  });
+}
+
 describe("scripts/test-extension.mjs", () => {
   it("resolves channel-root extensions onto the channel vitest config", () => {
     const plan = resolveExtensionTestPlan({ targetArg: "slack", cwd: process.cwd() });
@@ -72,4 +79,18 @@ describe("scripts/test-extension.mjs", () => {
       [...extensionIds].toSorted((left, right) => left.localeCompare(right)),
     );
   });
+
+  it("dry-run still reports a plan for extensions without tests", () => {
+    const plan = readPlan(["copilot-proxy"]);
+
+    expect(plan.extensionId).toBe("copilot-proxy");
+    expect(plan.testFiles).toEqual([]);
+  });
+
+  it("treats extensions without tests as a no-op by default", () => {
+    const stdout = runScript(["copilot-proxy"]);
+
+    expect(stdout).toContain("No tests found for extensions/copilot-proxy.");
+    expect(stdout).toContain("Skipping.");
+  });
 });