feat: move toHaveScreenshot to use old snapshot paths by default (#14006)

Note: all toHaveScreenshot tests still use `__screenshots__` directory
for their expectations. One more test was added to make sure that
by default, `toHaveScreenshot` uses old snapshots.

packages/playwright-test/src/matchers/toMatchSnapshot.ts

@@ -295,8 +295,11 @@ export async function toHaveScreenshot(
   if (!testInfo)
     throw new Error(`toHaveScreenshot() must be called during the test`);
   const config = (testInfo.project._expect as any)?.toHaveScreenshot;
+  const snapshotPathResolver = process.env.PLAYWRIGHT_EXPERIMENTAL_FEATURES && config?._useScreenshotsDir
+    ? testInfo._screenshotPath.bind(testInfo)
+    : testInfo.snapshotPath.bind(testInfo);
   const helper = new SnapshotHelper(
-      testInfo, testInfo._screenshotPath.bind(testInfo), 'png',
+      testInfo, snapshotPathResolver, 'png',
       {
         maxDiffPixels: config?.maxDiffPixels,
         maxDiffPixelRatio: config?.maxDiffPixelRatio,

tests/playwright-test/reporter-html.spec.ts

@@ -180,7 +180,9 @@ test('should include multiple image diffs', async ({ runInlineTest, page, showRe
 
   const result = await runInlineTest({
     'playwright.config.ts': `
+      process.env.PLAYWRIGHT_EXPERIMENTAL_FEATURES = 1;
       module.exports = {
+        expect: { toHaveScreenshot: { _useScreenshotsDir: true } },
         screenshotsDir: '__screenshots__',
         use: { viewport: { width: ${IMG_WIDTH}, height: ${IMG_HEIGHT} }}
       };

tests/playwright-test/to-have-screenshot.spec.ts

@@ -97,6 +97,27 @@ test('should fail with proper error when unsupported argument is given', async (
   expect(stripAnsi(result.output)).toContain(`Expected options.clip.width not to be 0`);
 });
 
+test('should use match snapshot paths by default', async ({ runInlineTest }, testInfo) => {
+  const result = await runInlineTest({
+    // The helper function `playwrightConfig` injects a `_useScreenshotsDir` flag.
+    // Provide default config manually instead.
+    'playwright.config.js': `
+      process.env.PLAYWRIGHT_EXPERIMENTAL_FEATURES = '1';
+      module.exports = {};
+    `,
+    'a.spec.js': `
+      pwt.test('is a test', async ({ page }, testInfo) => {
+        testInfo.snapshotSuffix = '';
+        await expect(page).toHaveScreenshot('snapshot.png');
+      });
+    `
+  }, { 'update-snapshots': true });
+  expect(result.exitCode).toBe(0);
+
+  const snapshotOutputPath = testInfo.outputPath('a.spec.js-snapshots', 'snapshot.png');
+  expect(fs.existsSync(snapshotOutputPath)).toBe(true);
+});
+
 test('should have scale:css by default', async ({ runInlineTest }, testInfo) => {
   const result = await runInlineTest({
     ...playwrightConfig({ screenshotsDir: '__screenshots__' }),
@@ -692,14 +713,14 @@ test('should respect maxDiffPixels option', async ({ runInlineTest }) => {
 
   expect((await runInlineTest({
     ...playwrightConfig({
-      projects: [
-        {
-          screenshotsDir: '__screenshots__',
       expect: {
         toHaveScreenshot: {
           maxDiffPixels: BAD_PIXELS
         }
       },
+      projects: [
+        {
+          screenshotsDir: '__screenshots__',
         },
       ],
     }),
@@ -798,13 +819,13 @@ test('should respect maxDiffPixelRatio option', async ({ runInlineTest }) => {
 
   expect((await runInlineTest({
     ...playwrightConfig({
-      projects: [{
-        screenshotsDir: '__screenshots__',
       expect: {
         toHaveScreenshot: {
           maxDiffPixelRatio: BAD_RATIO,
         },
       },
+      projects: [{
+        screenshotsDir: '__screenshots__',
       }],
     }),
     '__screenshots__/a.spec.js/snapshot.png': EXPECTED_SNAPSHOT,
@@ -920,6 +941,9 @@ test('should update expectations with retries', async ({ runInlineTest }, testIn
 });
 
 function playwrightConfig(obj: any) {
+  obj.expect ??= {};
+  obj.expect.toHaveScreenshot ??= {};
+  obj.expect.toHaveScreenshot._useScreenshotsDir ??= true;
   return {
     'playwright.config.js': `
       process.env.PLAYWRIGHT_EXPERIMENTAL_FEATURES = '1';