Check file changes during test (denoland/deno_std#476)

Original: 7daa887b09

test.ts

@@ -21,4 +21,41 @@ import "./textproto/test.ts";
 import "./util/test.ts";
 import "./ws/test.ts";
 
-import "./testing/main.ts";
+import { xrun } from "./prettier/util.ts";
+import { red, green } from "./colors/mod.ts";
+import { runTests } from "./testing/mod.ts";
+
+async function run(): Promise<void> {
+  const startTime = Date.now();
+  await runTests();
+  await checkSourceFileChanges(startTime);
+}
+
+/**
+ * Checks whether any source file is changed since the given start time.
+ * If some files are changed, this function exits with 1.
+ */
+async function checkSourceFileChanges(startTime: number): Promise<void> {
+  console.log("test checkSourceFileChanges ...");
+  const changed = new TextDecoder()
+    .decode(await xrun({ args: ["git", "ls-files"], stdout: "piped" }).output())
+    .trim()
+    .split("\n")
+    .filter(file => {
+      const stat = Deno.lstatSync(file);
+      if (stat != null) {
+        return (stat as any).modified * 1000 > startTime;
+      }
+    });
+  if (changed.length > 0) {
+    console.log(red("FAILED"));
+    console.log(
+      `Error: Some source files are modified during test: ${changed.join(", ")}`
+    );
+    Deno.exit(1);
+  } else {
+    console.log(green("ok"));
+  }
+}
+
+run();