test(test-utils): utility for --turbo testing

test/lib/next-test-utils.js

@@ -867,3 +867,38 @@ export function findAllTelemetryEvents(output, eventName) {
   )
   return events.filter((e) => e.eventName === eventName).map((e) => e.payload)
 }
+
+/**
+ * Utility function to determine if a given test case needs to run with --turbo.
+ *
+ * This is primarily for the gradual test enablement with latest turbopack upstream changes.
+ *
+ * Note: it could be possible to dynamically create test cases itself (createDevTest(): it.each([...])), but
+ * it makes hard to conform with existing lint rules. Instead, starting off from manual fixture setup and
+ * update test cases accordingly as turbopack changes enable more test cases.
+ */
+export function shouldRunTurboDevTest() {
+  const shouldRunTurboDev = !!process.env.__INTERNAL_NEXT_DEV_TEST_TURBO_DEV
+  // short-circuit to run all the test with --turbo enabled skips glob matching costs
+  if (shouldRunTurboDev) {
+    return true
+  }
+
+  const shouldRunTurboDevWithMatches =
+    !!process.env.__INTERNAL_NEXT_DEV_TEST_TURBO_GLOB_MATCH
+
+  // By default, we do not run any tests with `--turbo` flag.
+  if (!shouldRunTurboDevWithMatches) {
+    return false
+  }
+
+  const glob = require('glob')
+  const matches = glob.sync(
+    process.env.__INTERNAL_NEXT_DEV_TEST_TURBO_GLOB_MATCH
+  )
+  const testPath = expect.getState().testPath
+  const isMatch = matches.some((match) => testPath.includes(match))
+
+  // If the test path matches the glob pattern, add additional case to run the test with `--turbo` flag.
+  return isMatch
+}