ci: commit ferric-example's declarations as a fixture instead of building them

kraenhansen suspected generateTypeScriptDeclarations doesn't actually skip a
native build. Confirmed: napi-rs's `napi build` has no typegen-only mode — it
always runs a real `cargo build`, and --dts-only leaves a fully populated
~123MB target/ directory (including a compiled libferric_example.so) behind.
"Skipping the native build entirely" was wrong; only Android/Apple
cross-compilation was actually skipped, and the lint job stayed coupled to
the host Rust toolchain's health exactly as #414 wanted to avoid.

Switch to the issue's other suggested option: commit ferric_example.d.ts and
ferric_example.js as a checked-in fixture (no longer gitignored), and drop
the ferric-example build:types step from the lint job entirely — it no
longer needs to regenerate anything. --dts-only stays, now documented
accurately, as the way to regenerate the fixture by hand after changing
packages/ferric-example/src/lib.rs.

To catch drift, the two CI jobs that already do a real `ferric build`
(Android and Apple triplets) now `git diff --exit-code` the two committed
files right after building. Both are label-gated rather than running on
every PR, so this doesn't fully close the gap — flagged in the PR thread.

Also excludes the two fixture files from Prettier: they're left in napi-rs's
own output formatting so regenerating them reproduces the committed bytes
exactly, and the new drift check doesn't false-positive on formatting alone.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DaK9eAAF5G8wj6UT8VekAm

Author: claude

.changeset/wet-carrots-relax.md

@@ -2,4 +2,4 @@
 "ferric-cli": patch
 ---
 
-Add `--dts-only` flag to `ferric build`, generating just the TypeScript declaration file and JS entrypoint without cross-compiling any Android/Apple binaries.
+Add `--dts-only` flag to `ferric build`, generating just the TypeScript declaration file and JS entrypoint without cross-compiling any Android/Apple binaries. It still runs a real host `cargo build` (napi-rs has no lighter typegen-only mode), so it's meant for regenerating a checked-in declarations fixture rather than for environments without a Rust toolchain.

.github/workflows/check.yml

@@ -64,11 +64,13 @@ jobs:
       # Generate the TypeScript/C++ declarations that other packages' type-checking
       # depends on, without building any native binaries: weak-node-api's
       # "prebuild:prepare" only copies headers and runs codegen (needs clang-format,
-      # set up above, but no JDK/Android SDK/NDK), and ferric's "--dts-only" flag
-      # runs a plain host `cargo build` to emit ferric-example's .d.ts instead of
-      # cross-compiling Android/Apple binaries. See #414.
+      # set up above, but no JDK/Android SDK/NDK). ferric-example's declarations are
+      # committed as a fixture instead (see packages/ferric-example/.gitignore) —
+      # napi-rs's dts generation has no way to run without a real `cargo build`
+      # (confirmed: it leaves a populated target/ directory), so unlike
+      # weak-node-api's codegen it can't be reproduced here without reintroducing a
+      # native build into the fastest-feedback job. See #414.
       - run: pnpm --filter weak-node-api run prebuild:prepare
-      - run: pnpm --filter @react-native-node-api/ferric-example run build:types
       - run: pnpm run lint
         env:
           DEBUG: eslint:eslint
@@ -342,6 +344,9 @@ jobs:
       - name: Build ferric-example for all architectures
         run: pnpm run build --android
         working-directory: packages/ferric-example
+      - name: Verify committed ferric-example TypeScript declarations are up to date
+        run: git diff --exit-code -- ferric_example.d.ts ferric_example.js
+        working-directory: packages/ferric-example
       - name: Run tests (Android)
         timeout-minutes: 75
         uses: reactivecircus/android-emulator-runner@v2
@@ -409,6 +414,9 @@ jobs:
       # Build Ferric example for all Apple architectures
       - run: pnpm exec ferric --apple
         working-directory: packages/ferric-example
+      - name: Verify committed ferric-example TypeScript declarations are up to date
+        run: git diff --exit-code -- ferric_example.d.ts ferric_example.js
+        working-directory: packages/ferric-example
       - name: Inspect the structure of the prebuilt binary
         run: |
           lipo -info ferric_example.apple.node/*/libferric_example.framework/libferric_example > lipo-output.txt

.prettierignore

@@ -14,3 +14,10 @@ packages/node-addon-examples/examples
 packages/node-tests/node
 packages/node-tests/tests
 packages/node-tests/*.generated.js
+
+# Committed napi-rs codegen fixture (see packages/ferric-example/.gitignore) — left
+# in napi-rs's own output formatting so `pnpm run build:types` reproduces it exactly
+# and the CI drift check (see .github/workflows/check.yml) doesn't false-positive on
+# formatting alone.
+packages/ferric-example/ferric_example.d.ts
+packages/ferric-example/ferric_example.js

packages/ferric-example/.gitignore

@@ -4,6 +4,9 @@
 /*.apple.node/
 /*.android.node/
 
-# Generated files
-/ferric_example.d.ts
-/ferric_example.js
+# ferric_example.d.ts and ferric_example.js are intentionally NOT ignored: they're
+# committed as a fixture so `pnpm run lint` (which apps/test-app's App.tsx needs for
+# its `typeof import("@react-native-node-api/ferric-example")`) doesn't have to run a
+# native `cargo build` to get them. See #414. Regenerate with `pnpm run build:types`
+# after changing packages/ferric-example/src/lib.rs, and let the "Test app (Android)"
+# / "Test ferric Apple triplets" jobs' drift check catch anyone who forgets.

packages/ferric-example/ferric_example.d.ts

@@ -0,0 +1,11 @@
+/**
+ * This file was generated by
+ * ╭─────────────────────────╮
+ * │░█▀▀░█▀▀░█▀▄░█▀▄░▀█▀░█▀▀░│
+ * │░█▀▀░█▀▀░█▀▄░█▀▄░░█░░█░░░│
+ * │░▀░░░▀▀▀░▀░▀░▀░▀░▀▀▀░▀▀▀░│
+ * ╰─────────────────────────╯
+ * Powered by napi.rs
+ */
+/* eslint-disable */
+export declare function sum(a: number, b: number): number

packages/ferric-example/ferric_example.js

@@ -0,0 +1,13 @@
+/* eslint-disable */
+
+/**
+ * This file was generated by
+ * ╭─────────────────────────╮
+ * │░█▀▀░█▀▀░█▀▄░█▀▄░▀█▀░█▀▀░│
+ * │░█▀▀░█▀▀░█▀▄░█▀▄░░█░░█░░░│
+ * │░▀░░░▀▀▀░▀░▀░▀░▀░▀▀▀░▀▀▀░│
+ * ╰─────────────────────────╯
+ * Powered by napi.rs
+ */
+
+module.exports = require('./ferric_example.node');

packages/ferric/src/build.ts

@@ -106,7 +106,7 @@ const xcframeworkExtensionOption = new Option(
 ).default(false);
 const dtsOnlyOption = new Option(
   "--dts-only",
-  "Only generate the TypeScript declarations, skipping the native build entirely (no Android/Apple toolchain needed)",
+  "Only generate the TypeScript declarations and entrypoint, skipping Android/Apple cross-compilation. Still runs a real `cargo build` for the host target (napi-rs has no lighter typegen-only mode), so this is not a no-op — it's meant for regenerating a checked-in declarations fixture, not for toolchain-free environments.",
 ).default(false);
 
 const outputPathOption = new Option(