feat(spm): auto-redirect non-destructive actions into ios/; fix Flow parse errors

UX: when invoked from the JS root of a standard RN app (cwd === projectRoot,
ios/ subdir exists), automatically run the action inside <projectRoot>/ios
with a yellow banner instead of erroring. Saves the user a read-error /
cd ios / retype-command cycle for the routine path. `clean` keeps refusing
because its destructive scopes (--project, --derived-data, --cache) shouldn't
silently retarget a different directory.

- New `detectStandardRnLayoutRedirect(appRoot, projectRoot)` helper: pure
  detection, returns the ios/ subdir or null.
- `describeRnRootMismatch` refactored to delegate to it (public contract
  preserved; still used by the clean refuse path).
- main() flips `appRoot` to the redirect target before any sub-script
  invocation when the action is non-destructive.
- 4 new unit tests covering the detection helper.

Flow parse-error cleanup (pre-existing, unblocked while in the area):
- spm/download-spm-artifacts.js:637 — type cast moved to a separate binding
  so it doesn't sit between `)` and `.member`.
- spm/download-spm-artifacts.js:740/:743 — same pattern for two inline-
  returned object literals.
- spm/spm-pbxproj.js:113 — dropped the dangling `/*: any */` cast that
  appeared after the trailing `;`; consolidated FlowFixMe to the call line.
- Once the parse errors cleared, the cascading untyped-import on
  setup-apple-spm.js:76 resolved automatically.

Author: chrfalch

packages/react-native/scripts/setup-apple-spm.js

@@ -647,10 +647,12 @@ function resolveAction(
  * silently skip every npm native dep. The build "succeeds" but anything
  * touching a native module crashes at runtime.
  *
- * Returns null when the cwd is fine, or a string describing the problem
- * when the user should `cd` into `ios/`.
+ * Returns the absolute path to the redirected app root (`<projectRoot>/ios`)
+ * when the redirect heuristic applies, else null. Pure: no side effects.
+ * The caller decides whether to auto-redirect (non-destructive actions) or
+ * refuse (destructive actions like `clean`).
  */
-function describeRnRootMismatch(
+function detectStandardRnLayoutRedirect(
   appRoot /*: string */,
   projectRoot /*: string */,
 ) /*: string | null */ {
@@ -663,13 +665,27 @@ function describeRnRootMismatch(
   // Standard RN layout has an `ios/` subdir holding the native project.
   // Without it (e.g. rn-tester's flat layout), no mismatch to flag.
   const iosSubdir = path.join(projectRoot, 'ios');
-  let isDir = false;
   try {
-    isDir = fs.statSync(iosSubdir).isDirectory();
+    if (!fs.statSync(iosSubdir).isDirectory()) {
+      return null;
+    }
   } catch {
     return null;
   }
-  if (!isDir) {
+  return iosSubdir;
+}
+
+/**
+ * Formats the refuse-message for destructive actions (`clean`) — and for
+ * tooling that wants the long explanation. Returns null when no mismatch
+ * is detected (delegates the detection to detectStandardRnLayoutRedirect).
+ */
+function describeRnRootMismatch(
+  appRoot /*: string */,
+  projectRoot /*: string */,
+) /*: string | null */ {
+  const iosSubdir = detectStandardRnLayoutRedirect(appRoot, projectRoot);
+  if (iosSubdir == null) {
     return null;
   }
   return (
@@ -1168,23 +1184,34 @@ function logNextSteps(
 }
 
 async function main(argv /*:: ?: Array<string> */) /*: Promise<void> */ {
-  const appRoot = process.cwd();
+  let appRoot = process.cwd();
   const projectRoot = findProjectRoot(appRoot);
   const args = parseArgs(argv ?? process.argv.slice(2));
   const action = resolveAction(args.action, appRoot);
 
+  // Standard-RN-layout redirect: if invoked from the JS root and there's an
+  // `ios/` subdir, route the run there. `clean` keeps refusing because its
+  // destructive scopes (--project, --derived-data, --cache) shouldn't
+  // silently retarget a different directory.
+  const redirectTo = detectStandardRnLayoutRedirect(appRoot, projectRoot);
+  if (redirectTo != null) {
+    if (action === 'clean') {
+      logError(describeRnRootMismatch(appRoot, projectRoot) ?? '');
+      process.exitCode = 1;
+      return;
+    }
+    log(
+      `\x1b[33mDetected standard RN layout — running ${action} in ${displayPath(redirectTo)} ` +
+        `instead of ${displayPath(appRoot)}.\x1b[0m`,
+    );
+    appRoot = redirectTo;
+  }
+
   log(`Running SPM ${action} in: ${displayPath(appRoot)}`);
   if (projectRoot !== appRoot) {
     log(`Project root (package.json): ${displayPath(projectRoot)}`);
   }
 
-  const mismatch = describeRnRootMismatch(appRoot, projectRoot);
-  if (mismatch != null) {
-    logError(mismatch);
-    process.exitCode = 1;
-    return;
-  }
-
   if (action === 'clean') {
     const wantProject = args.cleanProject || args.cleanAll;
     const wantDerivedData = args.cleanDerivedData || args.cleanAll;
@@ -1376,6 +1403,7 @@ module.exports = {
   cleanGeneratedState,
   gatherCleanTargets,
   describeRnRootMismatch,
+  detectStandardRnLayoutRedirect,
   findExistingSpmXcodeproj,
   findLegacyXcodeproj,
   podfileNeedsPatch,

packages/react-native/scripts/spm/__tests__/setup-apple-spm-test.js

@@ -12,6 +12,7 @@
 
 const {
   describeRnRootMismatch,
+  detectStandardRnLayoutRedirect,
   findExistingSpmXcodeproj,
   findLegacyXcodeproj,
   gatherCleanTargets,
@@ -196,6 +197,48 @@ describe('describeRnRootMismatch', () => {
   });
 });
 
+// ---------------------------------------------------------------------------
+// detectStandardRnLayoutRedirect — pure detection helper used by main() to
+// decide whether to auto-redirect into the ios/ subdir. Non-destructive
+// actions (init/update/sync/codegen/download/scaffold) redirect with a
+// banner; clean keeps refusing via describeRnRootMismatch's full message.
+// ---------------------------------------------------------------------------
+
+describe('detectStandardRnLayoutRedirect', () => {
+  let tempDir;
+
+  beforeEach(() => {
+    tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'spm-redirect-'));
+  });
+
+  afterEach(() => {
+    fs.rmSync(tempDir, {recursive: true, force: true});
+  });
+
+  it('returns the ios/ subdir when cwd === projectRoot AND ios/ exists', () => {
+    fs.mkdirSync(path.join(tempDir, 'ios'));
+    expect(detectStandardRnLayoutRedirect(tempDir, tempDir)).toBe(
+      path.join(tempDir, 'ios'),
+    );
+  });
+
+  it('returns null when running from a subdirectory (already cd-ed)', () => {
+    fs.mkdirSync(path.join(tempDir, 'ios'));
+    expect(
+      detectStandardRnLayoutRedirect(path.join(tempDir, 'ios'), tempDir),
+    ).toBeNull();
+  });
+
+  it('returns null for flat layouts (no ios/ subdir, e.g. rn-tester)', () => {
+    expect(detectStandardRnLayoutRedirect(tempDir, tempDir)).toBeNull();
+  });
+
+  it('returns null when `ios` is a file, not a directory', () => {
+    fs.writeFileSync(path.join(tempDir, 'ios'), '');
+    expect(detectStandardRnLayoutRedirect(tempDir, tempDir)).toBeNull();
+  });
+});
+
 // ---------------------------------------------------------------------------
 // findLegacyXcodeproj + podfileNeedsPatch — Podfile auto-patch helpers.
 // CocoaPods refuses to choose between sibling xcodeprojs when the Podfile

packages/react-native/scripts/spm/download-spm-artifacts.js

@@ -632,9 +632,10 @@ async function main(argv /*:: ?: Array<string> */) /*: Promise<void> */ {
   let rnVersion = args.version;
   if (rnVersion == null) {
     // $FlowFixMe[incompatible-type] JSON.parse returns any
-    rnVersion = JSON.parse(
+    const rnPkg /*: {version: string} */ = JSON.parse(
       fs.readFileSync(path.join(rnRoot, 'package.json'), 'utf8'),
-    ) /*: {version: string} */.version;
+    );
+    rnVersion = rnPkg.version;
   }
   if (rnVersion === '1000.0.0') {
     log('Detected dev version (1000.0.0), resolving as nightly...');
@@ -732,14 +733,19 @@ async function main(argv /*:: ?: Array<string> */) /*: Promise<void> */ {
           outputDir,
           makeCallback(index),
         );
-        return {
+        const ok /*: ArtifactResultEntry */ = {
           name: spec.name,
           error: undefined,
           ...r,
-        } /*: ArtifactResultEntry */;
+        };
+        return ok;
       } catch (e) {
         progress.update(index, `  ${spec.name}: FAILED - ${e.message}`);
-        return {name: spec.name, error: e.message} /*: ArtifactResultEntry */;
+        const failed /*: ArtifactResultEntry */ = {
+          name: spec.name,
+          error: e.message,
+        };
+        return failed;
       }
     }),
   );

packages/react-native/scripts/spm/spm-pbxproj.js

@@ -107,10 +107,9 @@ function scanProjectFiles(sourceDir /*: string */) /*: ProjectFiles */ {
     if (!fs.existsSync(dir)) {
       return;
     }
-    // $FlowFixMe[incompatible-type]
     const entries /*: Array<{name: string, isDirectory(): boolean}> */ =
-      // $FlowFixMe[unclear-type]
-      fs.readdirSync(dir, {withFileTypes: true}); /*: any */
+      // $FlowFixMe[incompatible-type] Dirent typing
+      fs.readdirSync(dir, {withFileTypes: true});
     for (const entry of entries) {
       if (entry.name.startsWith('.')) {
         continue;