test: isolate yarn global cache in test sandbox

Author: jbedard

tests/legacy-cli/e2e/setup/002-npm-sandbox.ts

@@ -1,22 +1,26 @@
 import { mkdir, writeFile } from 'fs/promises';
 import { join } from 'path';
-import { getGlobalVariable } from '../utils/env';
+import { getGlobalVariable, setGlobalVariable } from '../utils/env';
 
 /**
  * Configure npm to use a unique sandboxed environment.
  */
 export default async function () {
   const tempRoot: string = getGlobalVariable('tmp-root');
   const npmModulesPrefix = join(tempRoot, 'npm-global');
+  const yarnModuleCache = join(tempRoot, 'yarn-cache-folder');
+  const yarnModulesPrefix = join(tempRoot, 'yarn-global');
   const npmRegistry: string = getGlobalVariable('package-registry');
   const npmrc = join(tempRoot, '.npmrc');
+  const yarnrc = join(tempRoot, '.yarnrc');
 
   // Configure npm to use the sandboxed npm globals and rc file
   // From this point onward all npm transactions use the "global" npm cache
   // isolated within this e2e test invocation.
   process.env.NPM_CONFIG_USERCONFIG = npmrc;
   process.env.NPM_CONFIG_PREFIX = npmModulesPrefix;
   process.env.NPM_CONFIG_REGISTRY = npmRegistry;
+  process.env.YARN_CACHE_FOLDER = yarnModuleCache;
 
   // Snapshot builds may contain versions that are not yet released (e.g., RC phase main branch).
   // In this case peer dependency ranges may not resolve causing npm 7+ to fail during tests.
@@ -25,9 +29,22 @@ export default async function () {
     process.env['NPM_CONFIG_legacy_peer_deps'] = 'true';
   }
 
-  // Configure the registry and prefix used within the test sandbox
-  await writeFile(npmrc, `registry=${npmRegistry}\nprefix=${npmModulesPrefix}`);
+  // Configure the registry and create the prefix directories
+  await writeFile(npmrc, [`registry=${npmRegistry}`, `prefix=${npmModulesPrefix}`].join('\n'));
+  await writeFile(
+    yarnrc,
+    [
+      `registry ${npmRegistry}`,
+      `prefix ${yarnModulesPrefix}`,
+      `cache-folder ${yarnModuleCache}`,
+    ].join('\n'),
+  );
   await mkdir(npmModulesPrefix);
+  await mkdir(yarnModulesPrefix);
+  await mkdir(yarnModuleCache);
+
+  setGlobalVariable('npm-global', npmModulesPrefix);
+  setGlobalVariable('yarn-global', yarnModulesPrefix);
 
   console.log(`  Using "${npmModulesPrefix}" as e2e test global npm cache.`);
 }

tests/legacy-cli/e2e/utils/process.ts

@@ -16,7 +16,7 @@ interface ExecOptions {
   cwd?: string;
 }
 
-const NPM_CONFIG_RE = /^npm_config_/i;
+const NPM_CONFIG_RE = /^(npm_config_|yarn_)/i;
 
 let _processes: child_process.ChildProcess[] = [];