feat(release): fingerprint the native surface so an OTA cannot outrun the binary

.github/workflows/capgo-deploy.yml

@@ -203,6 +203,38 @@ jobs:
                   echo "name=$FLOOR" >> "$GITHUB_OUTPUT"
                   echo "Bundle requires native $FLOOR or newer"
 
+            # The floor above says which binary this bundle CLAIMS to need. This
+            # step checks the claim: if the native surface moved since that
+            # binary was cut, the JS being published was built against plugins,
+            # permissions or entitlements no shipped binary has, and the floor is
+            # a number rather than a fact.
+            #
+            # A bundle's version says nothing about the native surface it needs,
+            # so nothing else in this pipeline can tell. Capgo's
+            # min_update_version only blocks DELIVERY, only under the `metadata`
+            # channel strategy, and lives in a dashboard CI cannot read — it
+            # never reports that an incompatible bundle was built. The
+            # fingerprint is a pure function of the tree, so the shipped binary's
+            # surface is exactly what its tag describes and no state has to be
+            # stored anywhere.
+            #
+            # Failing here is the intended outcome, not an obstacle: it is
+            # docs/NATIVE-RELEASE.md's "bump the native version whenever you
+            # change plugins/native code" with something actually checking it.
+            # The fix is to cut a native release, never to weaken this step.
+            - name: Check the native surface still matches that binary
+              env:
+                  FLOOR: ${{ steps.native_floor.outputs.name }}
+              run: |
+                  if ! git rev-parse -q --verify "refs/tags/v$FLOOR" >/dev/null; then
+                      echo "::error::no v$FLOOR tag in this checkout — cannot prove the bundle fits the binary it targets (needs fetch-depth: 0 and tags)" >&2
+                      exit 1
+                  fi
+                  if ! node scripts/native-fingerprint.mjs --diff "v$FLOOR"; then
+                      echo "::error::this tree's native surface differs from the v$FLOOR binary, so the JS about to ship was built against native code no released binary has. Cut a native release (Actions -> Release Native) before OTA'ing this tree." >&2
+                      exit 1
+                  fi
+
             - name: Upload bundle to Capgo
               # Commit message via env, never inline — a multi-line message (or one
               # with quotes) injected into the run script breaks --comment quoting.

docs/NATIVE-RELEASE.md

@@ -336,6 +336,26 @@ own `out/` under the binary's versionName, then assert the channel serves it.
   the floor when the channel's "disable auto update" strategy is set to *version number*.
   **Bump the native version whenever you change plugins/native code**, then ship that via
   Play — OTA can't.
+- **Native fingerprint (the check behind that rule):** `scripts/native-fingerprint.mjs`
+  hashes the JS↔native contract in three parts: the **config** (Capacitor's two generated
+  plugin manifests, `capacitor.config.ts`, the gradle files, `AndroidManifest.xml`,
+  `project.pbxproj`, `Info.plist`, both entitlements files), the **bridges** JS actually
+  calls (`android/app/src/**.{java,kt}`, `ios/App/**.swift` — a bundle calling a new
+  method on `PushProvisioningPlugin` needs the binary that has it, and no config file
+  moves when that changes), and the **resolved plugin versions from `pnpm-lock.yaml`**
+  (the OTA workflow runs `pnpm install` but never regenerates the committed manifests, so
+  a plugin bumped without a `cap sync` would ship the new JS wrapper against unchanged
+  manifest bytes). `capgo-deploy.yml` recomputes it and compares against the
+  `v<major>.<build>.0` tag the bundle's floor targets; a mismatch **fails the OTA** and
+  names the file that moved. It is a pure function of the tree, so nothing is stored and
+  any tag can be fingerprinted retroactively (`--ref v1.2.0`). `MARKETING_VERSION` and
+  `CURRENT_PROJECT_VERSION` are normalised out — `native-ios-postsync.js` stamps them on
+  every sync, and leaving them in would refuse an OTA after every release.
+  **Why it exists:** `min_update_version` only blocks *delivery*, only under the
+  `metadata` channel strategy, and lives in a dashboard CI cannot read, so nothing
+  previously reported that an incompatible bundle had been *built* — the mismatch first
+  appeared on a user's device. The remedy for a failure is always to cut a native
+  release, never to widen or skip the check.
 - **Staged rollout:** roll production OTA to ~10% → watch Sentry/crash + error rates →
   100%. Don't 100% every merge.
 - **Rollback** is configured in `capacitor.config.ts` (`appReadyTimeout: 15000` +

scripts/__tests__/native-fingerprint.test.js

@@ -0,0 +1,196 @@
+const { spawnSync } = require('child_process')
+const fs = require('fs')
+const path = require('path')
+
+const SCRIPT_PATH = path.join(__dirname, '..', 'native-fingerprint.mjs')
+const repoRoot = path.join(__dirname, '..', '..')
+
+// The script is a CI entrypoint: its contract is stdout + exit code, so run it
+// the way capgo-deploy.yml does instead of reaching into its internals. (Jest
+// runs CJS here, so a dynamic import of the .mjs would not load anyway — same
+// reason semver-newer.test.js and release-version.test.js spawn it.)
+function run(...args) {
+    return spawnSync(process.execPath, [SCRIPT_PATH, ...args], { encoding: 'utf-8', cwd: repoRoot })
+}
+
+function fingerprint(...args) {
+    const result = run(...args)
+    expect(result.status).toBe(0)
+    return result.stdout.trim()
+}
+
+// Mutate one native input, read the fingerprint, always put the file back.
+function withPatchedInput(relativePath, patch, assertion) {
+    const target = path.join(repoRoot, relativePath)
+    const original = fs.readFileSync(target, 'utf8')
+    try {
+        fs.writeFileSync(target, patch(original))
+        assertion()
+    } finally {
+        fs.writeFileSync(target, original)
+    }
+}
+
+describe('native-fingerprint', () => {
+    it('is a stable 16-hex digest across repeated runs of one tree', () => {
+        const first = fingerprint()
+
+        expect(first).toMatch(/^[0-9a-f]{16}$/)
+        expect(fingerprint()).toBe(first)
+    })
+
+    it('covers every native input, hashing it or recording its absence', () => {
+        const result = run('--manifest')
+        const entries = JSON.parse(result.stdout)
+
+        expect(result.status).toBe(0)
+        // toContain on the key list, not toHaveProperty: these keys contain
+        // dots, which toHaveProperty would read as a nested property path.
+        const keys = Object.keys(entries)
+        // The two generated plugin manifests are the load-bearing inputs: they
+        // pin the plugin set AND their resolved versions.
+        expect(keys).toContain('android/capacitor.settings.gradle')
+        expect(keys).toContain('ios/App/CapApp-SPM/Package.swift')
+        expect(keys).toContain('capacitor.config.ts')
+        // The bridges JS actually calls, and the lockfile the OTA build
+        // installs from — config files alone do not move when either changes.
+        expect(keys).toContain('android/app/src/**.{java,kt}')
+        expect(keys).toContain('ios/App/**.swift')
+        expect(keys).toContain('native-plugin-versions')
+        expect(keys.length).toBeGreaterThanOrEqual(10)
+
+        // Nothing is silently skipped — absence is its own sentinel, so adding
+        // or deleting a file moves the fingerprint.
+        for (const value of Object.values(entries)) {
+            expect(value === '<absent>' || /^[0-9a-f]{64}$/.test(value)).toBe(true)
+        }
+    })
+
+    it('reads a git ref, and differs from the working tree once native code has moved', () => {
+        // HEAD, never a release tag: the unit job checks out at depth 1 with no
+        // tags, so `--ref v1.1.0` resolves to nothing there and EVERY input
+        // reads <absent> — which still differs from the working tree, so a
+        // tag-based assertion passes for entirely the wrong reason.
+        expect(fingerprint('--ref', 'HEAD')).toMatch(/^[0-9a-f]{16}$/)
+        expect(fingerprint('--ref', 'HEAD')).toBe(fingerprint())
+
+        withPatchedInput(
+            'capacitor.config.ts',
+            (content) => `${content}\n// surface change\n`,
+            () => expect(fingerprint('--ref', 'HEAD')).not.toBe(fingerprint())
+        )
+    })
+
+    it('exits 0 and says so when the surface has not moved', () => {
+        const result = run('--diff', 'HEAD')
+
+        expect(result.status).toBe(0)
+        expect(result.stdout).toContain('native surface unchanged')
+    })
+
+    it('exits 1 naming the culprit when the surface moved', () => {
+        withPatchedInput(
+            'android/capacitor.settings.gradle',
+            (content) => content.replace('capacitor-updater@8.51.14', 'capacitor-updater@9.0.0'),
+            () => {
+                const result = run('--diff', 'HEAD')
+
+                expect(result.status).toBe(1)
+                expect(result.stdout).toContain('native surface changed since HEAD')
+                // The point of the check is that it says WHAT moved, not just
+                // that something did — a bare "refused" is unactionable at 2am.
+                expect(result.stdout).toContain('android/capacitor.settings.gradle')
+            }
+        )
+    })
+
+    it('moves when a plugin version changes', () => {
+        const before = fingerprint()
+
+        withPatchedInput(
+            'android/capacitor.settings.gradle',
+            // The shape of a real plugin bump: the resolved version lives in the
+            // dependency path Capacitor generates.
+            (content) => content.replace('capacitor-updater@8.51.14', 'capacitor-updater@9.0.0'),
+            () => expect(fingerprint()).not.toBe(before)
+        )
+    })
+
+    it('ignores the MARKETING_VERSION stamp, which is the release number not the surface', () => {
+        const before = fingerprint()
+
+        withPatchedInput(
+            'ios/App/App.xcodeproj/project.pbxproj',
+            // Exactly what scripts/native-ios-postsync.js writes on every cap
+            // sync. Left un-normalised this would refuse an OTA after every
+            // release, and the check would be turned off within a week.
+            (content) => content.replace(/MARKETING_VERSION = [^;]*;/g, 'MARKETING_VERSION = 9.9.9;'),
+            () => expect(fingerprint()).toBe(before)
+        )
+    })
+
+    it('still notices a real pbxproj change, e.g. the deployment floor', () => {
+        const before = fingerprint()
+
+        withPatchedInput(
+            'ios/App/App.xcodeproj/project.pbxproj',
+            (content) => content.replace(/IPHONEOS_DEPLOYMENT_TARGET = [^;]*;/g, 'IPHONEOS_DEPLOYMENT_TARGET = 18.0;'),
+            () => expect(fingerprint()).not.toBe(before)
+        )
+    })
+
+    it('moves when an Android bridge changes', () => {
+        const before = fingerprint()
+
+        withPatchedInput(
+            'android/app/src/main/java/me/peanut/wallet/MainActivity.java',
+            // MainActivity is where app-local plugins are registered, so a
+            // bundle calling a newly-registered one needs this binary. No
+            // config file moves when it changes.
+            (content) => `${content}\n// surface change\n`,
+            () => expect(fingerprint()).not.toBe(before)
+        )
+    })
+
+    it('moves when an iOS bridge changes', () => {
+        const before = fingerprint()
+
+        withPatchedInput(
+            'ios/App/App/ClipboardDetectPlugin.swift',
+            (content) => `${content}\n// surface change\n`,
+            () => expect(fingerprint()).not.toBe(before)
+        )
+    })
+
+    it('moves on a lockfile-only plugin bump, which the generated manifests miss', () => {
+        const before = fingerprint()
+
+        withPatchedInput(
+            'pnpm-lock.yaml',
+            // The gap this closes: the OTA workflow runs `pnpm install` but
+            // never regenerates capacitor.settings.gradle / Package.swift, so a
+            // plugin bumped without a `cap sync` ships the new JS wrapper while
+            // both generated manifests still read unchanged.
+            (content) => content.split('@capgo/capacitor-updater@8.51.14').join('@capgo/capacitor-updater@9.0.0'),
+            () => expect(fingerprint()).not.toBe(before)
+        )
+    })
+
+    it('resolves the bridge file sets at a git ref, not just in the working tree', () => {
+        // Regression guard: `git ls-tree -r -- 'dir/**/*.java'` matches nothing
+        // and exits 0, so a glob pathspec made every ref report an empty bridge
+        // set — the check compared nothing against nothing and passed.
+        const entries = JSON.parse(run('--manifest', '--ref', 'HEAD').stdout)
+
+        expect(entries['android/app/src/**.{java,kt}']).not.toBe('<absent>')
+        expect(entries['ios/App/**.swift']).not.toBe('<absent>')
+        expect(entries['native-plugin-versions']).not.toBe('<absent>')
+    })
+
+    it('rejects --diff without a ref rather than comparing against nothing', () => {
+        const result = run('--diff')
+
+        expect(result.status).toBe(1)
+        expect(result.stderr).toContain('needs a git ref')
+    })
+})