fix(check): exclude test-runner files from app compatibility scans (#2596)

* fix(check): exclude test-runner files from app compatibility scans

vinext check scans test modules and test-runner configuration as though they are bundled into the migrated application. Apps using CommonJS globals only in Vitest files therefore receive unsupported migration issues even when the vinext build succeeds.

Separate the application compatibility candidate set from the general recursive file finder. Exclude test and spec modules plus conventional Jest, Playwright, and Vitest config files, while keeping ordinary runtime config modules visible to import and convention checks.

* ci: rerun performance benchmarks

---------

Co-authored-by: James Anderson <james@eli.cx>

Author: NathanDrake2406

packages/vinext/src/check.ts

@@ -378,6 +378,20 @@ function findSourceFiles(
   return results;
 }
 
+/**
+ * Find files that can contribute to the application compatibility surface.
+ * Test modules and test-runner configuration are executed by their own runners
+ * rather than bundled into the vinext application, so reporting their imports
+ * or CJS globals as migration blockers produces false positives.
+ */
+function findRuntimeSourceFiles(root: string): string[] {
+  return findSourceFiles(root).filter((file) => {
+    const basename = path.basename(file);
+    const isTestRunnerConfig = /^(?:jest|playwright|vitest)\.config\.[cm]?[jt]sx?$/.test(basename);
+    return !/\.(?:test|spec)\.[cm]?[jt]sx?$/.test(basename) && !isTestRunnerConfig;
+  });
+}
+
 function isIdentStart(c: string): boolean {
   return (c >= "a" && c <= "z") || (c >= "A" && c <= "Z") || c === "_" || c === "$";
 }
@@ -610,7 +624,7 @@ export function hasFreeCjsGlobal(content: string): boolean {
  * Scan source files for `import ... from 'next/...'` statements.
  */
 export function scanImports(root: string): CheckItem[] {
-  const files = findSourceFiles(root);
+  const files = findRuntimeSourceFiles(root);
   const importUsage = new Map<string, string[]>();
 
   const importRegex = /(?:import\s+(?:[\w{},\s*]+\s+from\s+)?|require\s*\()['"]([^'"]+)['"]\)?/g;
@@ -1078,7 +1092,7 @@ export function checkConventions(root: string): CheckItem[] {
   // For __dirname/__filename we use hasFreeCjsGlobal(), a single-pass scanner that
   // skips string literals, template literals, and comments before testing for the
   // identifier, so tokens inside those contexts are never matched.
-  const allSourceFiles = findSourceFiles(root);
+  const allSourceFiles = findRuntimeSourceFiles(root);
   const viewTransitionRegex = /import\s+\{[^}]*\bViewTransition\b[^}]*\}\s+from\s+['"]react['"]/;
   const viewTransitionFiles: string[] = [];
   const cjsGlobalFiles: string[] = [];

tests/check.test.ts

@@ -216,6 +216,17 @@ describe("scanImports", () => {
     expect(items[0].name).toBe("next/image");
   });
 
+  it("ignores imports used only by test modules and tool config files", () => {
+    writeFile("app/page.test.tsx", `import { useAmp } from "next/amp";`);
+    writeFile("vitest.config.ts", `import { useAmp } from "next/amp";`);
+    writeFile("site.config.ts", `import { useAmp } from "next/amp";`);
+    writeFile("app/page.tsx", `import Link from "next/link";`);
+
+    const items = scanImports(tmpDir);
+
+    expect(items.map((item) => item.name)).toEqual(["next/amp", "next/link"]);
+  });
+
   it("deduplicates files using the same import", () => {
     writeFile(
       "app/page.tsx",
@@ -1226,6 +1237,33 @@ describe("checkConventions", () => {
     expect(cjs?.files).toContain("lib/db.ts");
   });
 
+  it("ignores CJS globals in test modules and tool config files", () => {
+    writeFile(
+      "src/app/mobile-layout-alignment.test.ts",
+      `const css = readFileSync(resolve(__dirname, "film.module.css"), "utf-8");`,
+    );
+    writeFile("vitest.config.ts", `export default { root: path.resolve(__dirname, "./src") };`);
+    writeFile("app/page.tsx", `export default function Home() { return <div/>; }`);
+
+    const items = checkConventions(tmpDir);
+    const cjs = items.find((i) => i.name.includes("__dirname"));
+
+    expect(cjs).toBeUndefined();
+  });
+
+  it("still reports CJS globals in runtime source alongside excluded files", () => {
+    writeFile("lib/db.ts", `const dir = path.join(__dirname, "data");`);
+    writeFile("site.config.ts", `const root = path.join(__dirname, "content");`);
+    writeFile("lib/db.spec.ts", `const fixture = path.join(__dirname, "fixtures");`);
+    writeFile("vitest.config.ts", `export default { root: path.resolve(__dirname, "./src") };`);
+    writeFile("app/page.tsx", `export default function Home() { return <div/>; }`);
+
+    const items = checkConventions(tmpDir);
+    const cjs = items.find((i) => i.name.includes("__dirname"));
+
+    expect(cjs?.files).toEqual(["lib/db.ts", "site.config.ts"]);
+  });
+
   it("detects __filename usage", () => {
     writeFile("lib/logger.ts", `const file = __filename;`);
     writeFile("app/page.tsx", `export default function Home() { return <div/>; }`);