tests(watch): hash assertion for info-verbosity-off

test/binCases/watch/info-verbosity-off/info-verbosity-off.test.js

@@ -4,10 +4,38 @@ jest.setTimeout(10e6);
 /* eslint-disable node/no-unsupported-features  */
 /* eslint-disable node/no-unsupported-features/es-syntax  */
 
-const { runWatch, extractSummary } = require("../../../testUtils");
+const { extractSummary, extractHash, appendDataIfFileExists, runAndGetWatchProc } = require("../../../testUtils");
+const fs = require("fs");
+const path = require("path");
 
-test("info-verbosity-off", async done => {
-	const result = await runWatch(__dirname, [
+const fileToChange = "index.js";
+const copyFile = "index_copy.js";
+const fileToChangePath = path.resolve(__dirname, fileToChange);
+const copyFilePath = path.resolve(__dirname, copyFile);
+
+// create copy of "index.js" => "index_copy.js"
+beforeEach(() => {
+	// fs.copyFileSync was added in Added in: v8.5.0
+	// We should migrate it once we stop support for v6.x
+	fs.createReadStream(fileToChangePath).pipe(fs.createWriteStream(copyFilePath));
+});
+
+afterEach(() => {
+	try {
+		// deleting the file as it is modified by the test
+		// subsequent test-case runs won't pass as snapshot is not matched
+		fs.unlinkSync(fileToChangePath);
+	} catch (e) {
+		console.warn("could not remove the file:" + fileToChangePath + "\n" + e.message);
+	} finally {
+		fs.renameSync(copyFilePath, fileToChangePath);
+	}
+});
+
+// It is modifying the index.js
+// Which breaks the test-cases second time
+test.only("info-verbosity-off", async done => {
+	var webpackProc = runAndGetWatchProc(__dirname, [
 		"--entry ",
 		"./index.js",
 		"--config",
@@ -22,15 +50,39 @@ test("info-verbosity-off", async done => {
 		"--info-verbosity",
 		"none"
 	]);
-	const { stdout, stderr } = result;
 
-	const summary = extractSummary(stdout);
+	var outputCount = 0;
+	var hash1;
+
+	webpackProc.stdout.on("data", data => {
+		data = data.toString();
+
+		if (outputCount === 0) {
+			hash1 = extractHash(data);
+
+			const summary = extractSummary(data);
+
+			expect(summary).toEqual(expect.anything());
+			expect(summary).toContain("");
+			expect(summary).not.toContain("webpack is watching the files…");
+			expect(summary).toMatchSnapshot();
+
+			// change file
+			appendDataIfFileExists(__dirname, fileToChange, "//junk-comment");
+
+			outputCount++;
+		} else {
+			const hash2 = extractHash(data);
 
-	expect(summary).toEqual(expect.anything());
-	expect(summary).toContain("");
-	expect(summary).not.toContain("webpack is watching the files…");
+			expect(hash2.hash).not.toBe(hash1.hash);
+			webpackProc.kill();
+			done();
+		}
+	});
 
-	expect(stderr).toHaveLength(0);
-	expect(summary).toMatchSnapshot();
-	done();
+	webpackProc.stderr.on("data", error => {
+		// fail test case if there is any error
+		expect(true).toBe(false);
+		done();
+	});
 });