Fix: test coverage node_modules exclusion in Windows (#12691)

src/cli/test_command.zig

@@ -598,7 +598,7 @@ const Scanner = struct {
         };
 
         // always ignore node_modules.
-        if (strings.contains(slice, "/" ++ "node_modules" ++ "/")) {
+        if (strings.contains(slice, "/node_modules/") or strings.contains(slice, "\\node_modules\\")) {
             return false;
         }
 

test/cli/test/coverage.test.ts

@@ -54,3 +54,26 @@ export class Y {
   expect(result.signalCode).toBeUndefined();
   expect(readFileSync(path.join(dir, "coverage", "lcov.info"), "utf-8")).toMatchSnapshot();
 });
+
+test("coverage excludes node_modules directory", () => {
+  const dir = tempDirWithFiles("cov", {
+    "node_modules/pi/index.js": `
+    export const pi = 3.14;
+    `,
+    "demo.test.ts": `
+    import { pi } from 'pi';
+    console.log(pi);
+    `,
+  });
+  const result = Bun.spawnSync([bunExe(), "test", "--coverage"], {
+    cwd: dir,
+    env: {
+      ...bunEnv,
+    },
+    stdio: [null, null, "pipe"],
+  });
+  expect(result.stderr.toString("utf-8")).toContain("demo.test.ts");
+  expect(result.stderr.toString("utf-8")).not.toContain("node_modules");
+  expect(result.exitCode).toBe(0);
+  expect(result.signalCode).toBeUndefined();
+});