test: fix flaky watching file cases

tests/integration/cli/build-watch/build.test.ts

@@ -1,12 +1,11 @@
-import { spawn } from 'node:child_process';
 import path from 'node:path';
 import { stripVTControlCharacters as stripAnsi } from 'node:util';
 import { describe, expect, onTestFinished, test } from '@rstest/core';
 import fse from 'fs-extra';
 import {
+  expectBuildEnd,
   expectFile,
-  expectFileChanges,
-  rslibBinPath,
+  expectFileWithContent,
   runCli,
 } from 'test-helper';
 
@@ -91,8 +90,9 @@ export default defineConfig({
     },
   },
   performance: {
+    buildCache: false,
     printFileSize: false,
-  }
+  },
 });
 `,
     );
@@ -104,21 +104,19 @@ export default defineConfig({
     const distFooFile = path.join(__dirname, 'dist/esm/foo.js');
     const distFoo2File = path.join(__dirname, 'dist/esm/foo2.js');
 
-    const child = spawn(
-      'node',
-      [rslibBinPath, 'build', '--watch', '-c', tempConfigFile],
-      {
-        cwd: __dirname,
-        stdio: 'pipe',
-        shell: true,
-      },
-    );
-    await expectFile(distIndexFile);
+    const { child } = runCli(`build --watch -c ${tempConfigFile}`, {
+      cwd: __dirname,
+    });
+    await expectFileWithContent(distIndexFile, 'index');
 
     fse.outputFileSync(srcFooFile, `export const foo = 'foo';`);
+    await expectBuildEnd(child);
+    await expectFileWithContent(distFooFile, `'foo'`);
+
     fse.outputFileSync(srcFoo2File, `export const foo2 = 'foo2';`);
-    await expectFile(distFooFile);
-    await expectFile(distFoo2File);
+    await expectBuildEnd(child);
+    await expectFileWithContent(distFoo2File, 'foo2');
+
     const content1 = await fse.readFile(distFooFile, 'utf-8');
     expect(content1!).toMatchInlineSnapshot(`
       "const foo = 'foo';
@@ -137,12 +135,13 @@ export default defineConfig({
     fse.removeSync(srcIndexFile);
 
     // change
-    fse.outputFileSync(srcFooFile, `export const foo = 'foo1';`);
-    await expectFileChanges(distFooFile, content1, 'foo1');
+    fse.outputFileSync(srcFooFile, `export const foo1 = 'foo1';`);
+    await expectBuildEnd(child);
+    await expectFileWithContent(distFooFile, 'foo1');
     const content3 = await fse.readFile(distFooFile, 'utf-8');
     expect(content3!).toMatchInlineSnapshot(`
-      "const foo = 'foo1';
-      export { foo };
+      "const foo1 = 'foo1';
+      export { foo1 };
       "
     `);
 

tests/scripts/helper.ts

@@ -1,6 +1,8 @@
+import type { ChildProcess } from 'node:child_process';
 import fs from 'node:fs';
 import { platform } from 'node:os';
 import { join } from 'node:path';
+import { stripVTControlCharacters as stripAnsi } from 'node:util';
 import { expect } from '@playwright/test';
 import fse from 'fs-extra';
 import { convertPathToPattern, type GlobOptions, glob } from 'tinyglobby';
@@ -83,19 +85,38 @@ export const expectFile = (dir: string) =>
   expectPoll(() => fs.existsSync(dir)).toBeTruthy();
 
 /**
- * Expect a file to be changed and contain newContent
+ * Expect a file to exist and include specified content
  */
-export const expectFileChanges = async (
-  file: string,
-  oldContent: string,
-  newContent: string,
-) => {
-  await expectPoll(() => {
+export const expectFileWithContent = (
+  filePath: string,
+  expectedContent: string,
+) =>
+  expectPoll(() => {
     try {
-      const content = fse.readFileSync(file, 'utf-8');
-      return content !== oldContent && content.includes(newContent);
+      if (!fs.existsSync(filePath)) {
+        return false;
+      }
+      const content = fs.readFileSync(filePath, 'utf-8');
+      return content.includes(expectedContent);
     } catch {
       return false;
     }
   }).toBeTruthy();
-};
+
+/**
+ * Expect log output from child process
+ */
+export const expectLog = (child: ChildProcess, log: string) =>
+  new Promise<void>((resolve) => {
+    const listener = (chunk: Buffer) => {
+      if (stripAnsi(chunk.toString()).includes(log)) {
+        resolve();
+      }
+    };
+
+    child.stdout?.on('data', listener);
+    child.stderr?.on('data', listener);
+  });
+
+export const expectBuildEnd = (child: ChildProcess) =>
+  expectLog(child, 'built in');