chore: do not delete unused browsers when PLAYWRIGHT_SKIP_BROWSER_GC …

…is specified (#5827)

docs/src/installation.md

@@ -285,3 +285,11 @@ Playwright downloads Chromium, Firefox and WebKit browsers by default. To instal
 $ pip install playwright
 $ playwright install firefox
 ```
+
+## Stale browser removal
+
+Playwright keeps track of the clients that use its browsers. When there are no more clients that require particular
+version of the browser, that version is deleted from the system. That way you can safely use Playwright instances of
+different versions and at the same time, you don't waste disk space for the browsers that are no longer in use.
+
+To opt-out from the unused browser removal, you can set the `PLAYWRIGHT_SKIP_BROWSER_GC=1` environment variable.

src/install/installer.ts

@@ -95,14 +95,16 @@ async function validateCache(linksDir: string, browserNames: BrowserName[]) {
   }
 
   // 2. Delete all unused browsers.
-  let downloadedBrowsers = (await fsReaddirAsync(registryDirectory)).map(file => path.join(registryDirectory, file));
-  downloadedBrowsers = downloadedBrowsers.filter(file => isBrowserDirectory(file));
-  const directories = new Set<string>(downloadedBrowsers);
-  for (const browserDirectory of usedBrowserPaths)
-    directories.delete(browserDirectory);
-  for (const directory of directories) {
-    browserFetcher.logPolitely('Removing unused browser at ' + directory);
-    await removeFolderAsync(directory).catch(e => {});
+  if (!getAsBooleanFromENV('PLAYWRIGHT_SKIP_BROWSER_GC')) {
+    let downloadedBrowsers = (await fsReaddirAsync(registryDirectory)).map(file => path.join(registryDirectory, file));
+    downloadedBrowsers = downloadedBrowsers.filter(file => isBrowserDirectory(file));
+    const directories = new Set<string>(downloadedBrowsers);
+    for (const browserDirectory of usedBrowserPaths)
+      directories.delete(browserDirectory);
+    for (const directory of directories) {
+      browserFetcher.logPolitely('Removing unused browser at ' + directory);
+      await removeFolderAsync(directory).catch(e => {});
+    }
   }
 
   // 3. Install missing browsers for this package.