SPM: actually read the artifacts version pin back

`spm add --version <ver>` / `spm update --version <ver>` already wrote an
`artifactsVersionOverride` into the `.spm-injected.json` marker, and
`readArtifactsVersionOverride` already existed to read it back — but nothing
ever called it. Only the write half was wired; every reference to the reader
was a test.

The sole resolver, determineVersion, went straight from the `--version` flag to
node_modules/react-native/package.json. So after `spm add --version X`, a later
flagless `spm update` silently re-pointed the project at package.json's version
instead, while the marker went on claiming X. `--version` was effectively
single-use. In this monorepo package.json is 1000.0.0, which has no published
artifacts, so a flagless run after a pinned add fails outright — hence the
standing advice to pass `--version` on every invocation.

Insert the pin between the two existing sources:

    --version  ->  pinned override  ->  react-native/package.json

`spm download` and the scaffold path pick it up for free, since both use the
same resolved value. Since this is persistent state, log one line when the pin
is the source, so a stale pin is diagnosable rather than silent; there is still
no way to clear it short of `deinit`.

Three comments claimed the build-time sync read this override via
readArtifactsVersionOverride. It does not, and never did — the sync action
returns before artifacts are resolved at all. They now name the real consumer.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: chrfalch

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

@@ -44,8 +44,10 @@
  * directing you to `--deintegrate`).
  *
  * Options:
- *   --version <ver>             React Native version (default: the resolved
- *                               node_modules/react-native version).
+ *   --version <ver>             React Native version. Pinned into
+ *                               .spm-injected.json and reused by later runs
+ *                               until a new one is passed (default: the
+ *                               resolved node_modules/react-native version).
  *   --yes                       Skip the dirty-pbxproj confirmation prompt.
  *   [add] --xcodeproj <path>    Which .xcodeproj to inject into (when several).
  *   [add] --product-name <name> Which app target to inject into (when several).
@@ -89,10 +91,12 @@ const {
 const {main: generatePackage} = require('./spm/generate-spm-package');
 const {findSourcePath} = require('./spm/generate-spm-package');
 const {
+  SPM_INJECTED_MARKER,
   cleanupDanglingJavaScriptCoreRef,
   cleanupLeftoverPodsGroup,
   findInjectedXcodeproj,
   injectSpmIntoExistingXcodeproj,
+  readArtifactsVersionOverride,
   removeSpmInjection,
 } = require('./spm/generate-spm-xcodeproj');
 const {scaffoldAll} = require('./spm/scaffold-package-swift');
@@ -149,7 +153,7 @@ function parseArgs(argv /*: Array<string> */) /*: SetupArgs */ {
     .option('version', {
       type: 'string',
       describe:
-        'React Native version (e.g. 0.80.0). Defaults to the version in node_modules/react-native/package.json',
+        'React Native version (e.g. 0.80.0). Sticks: later runs reuse it until you pass a new one. Defaults to the version in node_modules/react-native/package.json',
     })
     .option('yes', {
       type: 'boolean',
@@ -373,19 +377,31 @@ function resolveReactNativeRoot(
   return reactNativeRoot;
 }
 
+// Explicit `--version` → the version an earlier `--version` pinned into the
+// injection marker → node_modules/react-native/package.json. The pin makes
+// `--version` stick for later flagless runs, which would otherwise re-point the
+// project at a different artifact slot than the one it was wired to.
 function determineVersion(
   args /*: SetupArgs */,
   reactNativeRoot /*: string */,
+  appRoot /*: string */,
 ) /*: string */ {
-  let version = args.version;
-  if (version == null) {
-    // $FlowFixMe[incompatible-type] JSON.parse returns any
-    const pkgJson /*: {version: string} */ = JSON.parse(
-      fs.readFileSync(path.join(reactNativeRoot, 'package.json'), 'utf8'),
+  if (args.version != null) {
+    return args.version;
+  }
+  const pinned = readArtifactsVersionOverride(appRoot);
+  if (pinned != null) {
+    log(
+      `Using version ${pinned} pinned in ${SPM_INJECTED_MARKER} by an earlier ` +
+        '--version. Pass --version to change it.',
     );
-    version = pkgJson.version;
+    return pinned;
   }
-  return version;
+  // $FlowFixMe[incompatible-type] JSON.parse returns any
+  const pkgJson /*: {version: string} */ = JSON.parse(
+    fs.readFileSync(path.join(reactNativeRoot, 'package.json'), 'utf8'),
+  );
+  return pkgJson.version;
 }
 
 function runCodegenStep(
@@ -438,7 +454,7 @@ async function runScaffold(
   // a comment — that's how SPM's manifest hash bumps on slot transitions.
   let cacheSlotLabel /*: ?string */ = null;
   try {
-    const rawVersion = args.version ?? determineVersion(args, reactNativeRoot);
+    const rawVersion = determineVersion(args, reactNativeRoot, appRoot);
     const slotVersion = await resolveCacheSlotVersion(rawVersion);
     cacheSlotLabel = `${slotVersion}/dual-flavor`;
   } catch {
@@ -1048,7 +1064,7 @@ async function main(argv /*:: ?: Array<string> */) /*: Promise<void> */ {
     autolinkingConfigResult,
     projectRoot,
   );
-  const version = determineVersion(args, reactNativeRoot);
+  const version = determineVersion(args, reactNativeRoot, appRoot);
   log(`React Native version: ${version}`);
 
   // Resolve remote SPM mode ONCE up front. remotePackageConfig throws
@@ -1210,6 +1226,7 @@ if (require.main === module) {
 module.exports = {
   main,
   detectStandardRnLayoutRedirect,
+  determineVersion,
   findInjectedXcodeproj,
   generateAutolinkingConfigOrFailClosed,
   parseArgs,

packages/react-native/scripts/spm/__tests__/remove-spm-injection-test.js

@@ -284,8 +284,8 @@ describe('generated-sources reconciliation on update', () => {
 
 // ---------------------------------------------------------------------------
 // artifactsVersionOverride — the marker field persisting an explicit
-// `spm add/update --version <ver>` pin (see setup-apple-spm.js /
-// sync-spm-autolinking.js). SETS on an explicit override; PRESERVES a
+// `spm add/update --version <ver>` pin (see setup-apple-spm.js's
+// determineVersion). SETS on an explicit override; PRESERVES a
 // previously-recorded value when the caller omits one; deinit drops it along
 // with the rest of the marker.
 // ---------------------------------------------------------------------------
@@ -366,9 +366,9 @@ describe('artifactsVersionOverride marker field', () => {
 });
 
 // ---------------------------------------------------------------------------
-// readArtifactsVersionOverride — pure fs read, used by the build-time sync
-// (sync-spm-autolinking.js) to prefer a pinned version over the one derived
-// from node_modules/react-native/package.json.
+// readArtifactsVersionOverride — pure fs read, used by setup-apple-spm.js's
+// determineVersion to prefer a pinned version over the one derived from
+// node_modules/react-native/package.json.
 // ---------------------------------------------------------------------------
 describe('readArtifactsVersionOverride', () => {
   it('returns null when no xcodeproj has been injected yet', () => {

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

@@ -12,6 +12,7 @@
 
 const {
   detectStandardRnLayoutRedirect,
+  determineVersion,
   ensureBothArtifactFlavors,
   findInjectedXcodeproj,
   generateAutolinkingConfigOrFailClosed,
@@ -28,12 +29,17 @@ const path = require('node:path');
 
 // Create an in-place-injected xcodeproj fixture: a directory carrying the
 // `.spm-injected.json` marker (what injectSpmIntoExistingXcodeproj writes).
-function mkInjectedXcodeproj(appRoot, name) {
+function mkInjectedXcodeproj(appRoot, name, extraMarkerFields = {}) {
   const dir = path.join(appRoot, name);
   fs.mkdirSync(dir, {recursive: true});
   fs.writeFileSync(
     path.join(dir, SPM_INJECTED_MARKER),
-    JSON.stringify({rootUuid: 'X', target: 'MyApp', injectedUuids: []}),
+    JSON.stringify({
+      rootUuid: 'X',
+      target: 'MyApp',
+      injectedUuids: [],
+      ...extraMarkerFields,
+    }),
   );
   return dir;
 }
@@ -388,3 +394,91 @@ describe('shouldAutoDeintegrate', () => {
     expect(shouldAutoDeintegrate(tempDir, xcodeproj)).toBe(true);
   });
 });
+
+// ---------------------------------------------------------------------------
+// determineVersion — which RN version the artifact slots are wired to:
+// explicit --version → the `artifactsVersionOverride` pinned in the injection
+// marker by a previous `--version` → node_modules/react-native/package.json.
+// ---------------------------------------------------------------------------
+
+describe('determineVersion', () => {
+  let appRoot;
+  let reactNativeRoot;
+  let logSpy;
+
+  beforeEach(() => {
+    appRoot = fs.mkdtempSync(path.join(os.tmpdir(), 'spm-version-app-'));
+    reactNativeRoot = fs.mkdtempSync(path.join(os.tmpdir(), 'spm-version-rn-'));
+    fs.writeFileSync(
+      path.join(reactNativeRoot, 'package.json'),
+      JSON.stringify({name: 'react-native', version: '1000.0.0'}),
+    );
+    logSpy = jest.spyOn(console, 'log').mockImplementation(() => {});
+  });
+
+  afterEach(() => {
+    jest.restoreAllMocks();
+    fs.rmSync(appRoot, {recursive: true, force: true});
+    fs.rmSync(reactNativeRoot, {recursive: true, force: true});
+  });
+
+  const logged = () => logSpy.mock.calls.map(c => c.join(' ')).join('\n');
+
+  it('prefers an explicit --version over a pinned override', () => {
+    mkInjectedXcodeproj(appRoot, 'MyApp.xcodeproj', {
+      artifactsVersionOverride: '0.80.0',
+    });
+
+    expect(
+      determineVersion({version: '0.81.0'}, reactNativeRoot, appRoot),
+    ).toBe('0.81.0');
+    expect(logged()).not.toMatch(/spm-injected\.json/);
+  });
+
+  it('uses the pinned override when --version is omitted', () => {
+    mkInjectedXcodeproj(appRoot, 'MyApp.xcodeproj', {
+      artifactsVersionOverride: '0.80.0',
+    });
+
+    expect(determineVersion({version: null}, reactNativeRoot, appRoot)).toBe(
+      '0.80.0',
+    );
+  });
+
+  it('names the marker in the log when the pin is the source', () => {
+    mkInjectedXcodeproj(appRoot, 'MyApp.xcodeproj', {
+      artifactsVersionOverride: '0.80.0',
+    });
+    determineVersion({version: null}, reactNativeRoot, appRoot);
+
+    expect(logged()).toMatch(/0\.80\.0/);
+    expect(logged()).toMatch(/spm-injected\.json/);
+  });
+
+  it("falls back to react-native's package.json with no pin recorded", () => {
+    mkInjectedXcodeproj(appRoot, 'MyApp.xcodeproj');
+
+    expect(determineVersion({version: null}, reactNativeRoot, appRoot)).toBe(
+      '1000.0.0',
+    );
+    expect(logged()).not.toMatch(/spm-injected\.json/);
+  });
+
+  it("falls back to react-native's package.json when no project is injected", () => {
+    mkXcodeproj(appRoot, 'MyApp.xcodeproj');
+
+    expect(determineVersion({version: null}, reactNativeRoot, appRoot)).toBe(
+      '1000.0.0',
+    );
+  });
+
+  it('falls back without throwing when the marker is corrupt', () => {
+    const xcodeproj = path.join(appRoot, 'MyApp.xcodeproj');
+    fs.mkdirSync(xcodeproj, {recursive: true});
+    fs.writeFileSync(path.join(xcodeproj, SPM_INJECTED_MARKER), '{not json');
+
+    expect(determineVersion({version: null}, reactNativeRoot, appRoot)).toBe(
+      '1000.0.0',
+    );
+  });
+});

packages/react-native/scripts/spm/generate-spm-xcodeproj.js

@@ -1856,9 +1856,9 @@ function readMarker(
 
 // Returns the `*.xcodeproj` under `appRoot` carrying a `.spm-injected.json`
 // marker (the user-owned project SPM packages were injected into in place),
-// or null when none has been injected yet. Pure fs reads — safe for the
-// build-time sync (sync-spm-autolinking.js, via readArtifactsVersionOverride
-// below) to call without pulling in any pbxproj-editing machinery at runtime.
+// or null when none has been injected yet. Pure fs reads — no pbxproj-editing
+// machinery, so cheap callers (action resolution, readArtifactsVersionOverride
+// below) can use it freely.
 function findInjectedXcodeproj(appRoot /*: string */) /*: string | null */ {
   let entries /*: Array<{name: string, isDirectory(): boolean}> */ = [];
   try {
@@ -1884,11 +1884,11 @@ function findInjectedXcodeproj(appRoot /*: string */) /*: string | null */ {
  * update --version` pinned into the injected xcodeproj's `.spm-injected.json`
  * marker (see the field's doc comment in injectSpmIntoExistingXcodeproj
  * below), or null when no project is injected yet, no override is pinned, or
- * the marker can't be read (never throws). Pure fs reads — the build-time
- * sync (sync-spm-autolinking.js) calls this to prefer the pinned version over
- * the one derived from node_modules/react-native/package.json, so a
- * version-mismatched setup keeps healing against the SAME artifact slot the
- * explicit `--version` selected.
+ * the marker can't be read (never throws). Pure fs reads — setup-apple-spm.js's
+ * determineVersion prefers the pinned version over the one derived from
+ * node_modules/react-native/package.json, so a later flagless `add`/`update`
+ * (and `download`) stays on the SAME artifact slot the explicit `--version`
+ * selected.
  */
 function readArtifactsVersionOverride(appRoot /*: string */) /*: ?string */ {
   const xcodeprojPath = findInjectedXcodeproj(appRoot);
@@ -2014,9 +2014,9 @@ function injectSpmIntoExistingXcodeproj(
   // intentional pin, not something to silently re-derive from
   // node_modules/react-native/package.json. There is no "clear" verb yet;
   // `deinit` (removeSpmInjection) drops the whole marker, including this
-  // field. Read back by readArtifactsVersionOverride (above) so the
-  // build-time sync (sync-spm-autolinking.js) heals against the SAME slot
-  // `add`/`update` selected, even on a version-mismatched setup.
+  // field. Read back by readArtifactsVersionOverride (above) so a later
+  // flagless `add`/`update`/`download` resolves to the SAME slot, even on a
+  // version-mismatched setup.
   const artifactsVersionOverride =
     opts.artifactsVersionOverride ??
     prevMarker?.artifactsVersionOverride ??