From e11aca5937b453a9717f6a423cd2525adae481b6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dawid=20Ma=C5=82ecki?= <maleckidawid@meta.com>
Date: Mon, 23 Jun 2025 01:16:57 -0700
Subject: [PATCH 1/7] Add diff-api-snapshot action to danger (#52045)

Summary:
This is a work in progress PR that adds breaking change detection to danger.

The danger is ran on a base revision from which there is no easy access to the API snapshot from the PR. The Github action fetches the PR and stores the "current" snapshot in the temporary directory which is then used in the `diff-api-snapshot` script. It is compared to the previous snapshot from the base revision which can be easily accessed by reading from `packages/react-native/ReactNativeApi.d.ts`.


## Changelog:

<!-- Help reviewers and the release process by writing your own changelog entry.

Pick one each for the category and type tags:

[ANDROID|GENERAL|IOS|INTERNAL] [BREAKING|ADDED|CHANGED|DEPRECATED|REMOVED|FIXED|SECURITY] - Message

For more details, see:
https://reactnative.dev/contributing/changelogs-in-pull-requests


Test Plan:
Tested on react-native fork with personal access token.

 {F1979339175}

https://github.com/coado/react-native/pull/16

Differential Revision: D76735630

Pulled By: coado
---
 .../diff-js-api-breaking-changes/action.yml   | 21 +++++++++++++++++++
 .github/workflows/danger-pr.yml               |  2 ++
 private/react-native-bots/dangerfile.js       | 21 +++++++++++++++++++
 3 files changed, 44 insertions(+)
 create mode 100644 .github/actions/diff-js-api-breaking-changes/action.yml

diff --git a/.github/actions/diff-js-api-breaking-changes/action.yml b/.github/actions/diff-js-api-breaking-changes/action.yml
new file mode 100644
index 00000000000000..8ce43380312b6d
--- /dev/null
+++ b/.github/actions/diff-js-api-breaking-changes/action.yml
@@ -0,0 +1,21 @@
+name: diff-js-api-breaking-changes
+description: Check for breaking changes in the public React Native JS API=
+runs:
+  using: composite
+  env:
+    SCRATCH_DIR: ${{ runner.temp }}/diff-js-api-breaking-changes
+  steps:
+    - name: Fetch snapshot from PR head
+      shell: bash
+      run: |
+        mkdir $SCRATCH_DIR
+        git fetch --depth=1 origin ${{ github.event.pull_request.head.sha }}
+        git show ${{ github.event.pull_request.head.sha }}:packages/react-native/ReactNativeApi.d.ts > $SCRATCH_DIR/ReactNativeApi-after.d.ts \
+          || echo "" > $SCRATCH_DIR/ReactNativeApi.d.ts
+    - name: Run breaking change detection
+      shell: bash
+      run: |
+        node ./scripts/diff-api-snapshot \
+        ${{ github.workspace }}/packages/react-native/ReactNativeApi.d.ts  \
+        $SCRATCH_DIR/ReactNativeApi-after.d.ts \
+        > $SCRATCH_DIR/output.json
diff --git a/.github/workflows/danger-pr.yml b/.github/workflows/danger-pr.yml
index 39a0e1c4922a15..cf28b788105a76 100644
--- a/.github/workflows/danger-pr.yml
+++ b/.github/workflows/danger-pr.yml
@@ -22,6 +22,8 @@ jobs:
         uses: ./.github/actions/setup-node
       - name: Run yarn install
         uses: ./.github/actions/yarn-install
+      - name: Run diff-js-api-breaking-changes
+        uses: ./.github/actions/diff-js-api-breaking-changes
       - name: Danger
         run: yarn danger ci --use-github-checks --failOnErrors
         working-directory: private/react-native-bots
diff --git a/private/react-native-bots/dangerfile.js b/private/react-native-bots/dangerfile.js
index ddec0bdbc60d13..1bff20819a9709 100644
--- a/private/react-native-bots/dangerfile.js
+++ b/private/react-native-bots/dangerfile.js
@@ -11,6 +11,8 @@
 'use strict';
 
 const {danger, fail, warn} = require('danger');
+const fs = require('fs');
+const path = require('path');
 
 const body = danger.github.pr.body?.toLowerCase() ?? '';
 
@@ -28,6 +30,25 @@ const isFromPhabricator = body_contains('differential revision:');
 // Provides advice if a summary section is missing, or body is too short
 const includesSummary = body_contains('## summary', 'summary:');
 
+const snapshot_output = JSON.parse(
+  fs.readFileSync(
+    path.join(
+      process.env.RUNNER_TEMP,
+      'diff-js-api-breaking-changes/output.json',
+    ),
+    'utf8',
+  ),
+);
+if (snapshot_output && snapshot_output.result !== 'NON_BREAKING') {
+  const title = ':exclamation: JavaScript API change detected';
+  const idea =
+    'This PR commits an update to ReactNativeApi.d.ts, indicating a change to React Native&#39;s public JavaScript API. ' +
+    'Please include a clear changelog message. ' +
+    'This change will be subject to extra review.\n\n' +
+    `This change was flagged as: <code>${snapshot_output.result}</code>`;
+  warn(`${title} - <i>${idea}</i>`);
+}
+
 const hasNoUsefulBody =
   !danger.github.pr.body || danger.github.pr.body.length < 50;
 const hasTooShortAHumanSummary =

From 5c59dbbaa2f153f09f966d9aa6f5fe436c50fc3a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dawid=20Ma=C5=82ecki?= <maleckidawid@meta.com>
Date: Mon, 23 Jun 2025 10:26:32 +0200
Subject: [PATCH 2/7] commit api

---
 packages/react-native/ReactNativeApi.d.ts | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 packages/react-native/ReactNativeApi.d.ts

diff --git a/packages/react-native/ReactNativeApi.d.ts b/packages/react-native/ReactNativeApi.d.ts
new file mode 100644
index 00000000000000..9efd0983af405d
--- /dev/null
+++ b/packages/react-native/ReactNativeApi.d.ts
@@ -0,0 +1,5 @@
+
+export interface ReactNativeApi {
+    foo: string,
+    bar: number,
+}

From 8d57818176172ab2097a4ddc02e5eb7b6625cd5b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dawid=20Ma=C5=82ecki?= <maleckidawid@meta.com>
Date: Mon, 23 Jun 2025 10:29:12 +0200
Subject: [PATCH 3/7] run on this fork

---
 .github/workflows/danger-pr.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/danger-pr.yml b/.github/workflows/danger-pr.yml
index cf28b788105a76..06daf7ee8378c8 100644
--- a/.github/workflows/danger-pr.yml
+++ b/.github/workflows/danger-pr.yml
@@ -15,7 +15,7 @@ permissions:
 jobs:
   danger:
     runs-on: ubuntu-latest
-    if: github.repository == 'facebook/react-native'
+    if: github.repository == 'coado/react-native'
     steps:
       - uses: actions/checkout@v4
       - name: Setup Node.js

From 7772526712fc6fbd32b766c7da8d00924e1551e6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dawid=20Ma=C5=82ecki?= <maleckidawid@meta.com>
Date: Mon, 23 Jun 2025 10:31:09 +0200
Subject: [PATCH 4/7] Test danger on empty commit


From b0de26b21ef1f72986764756f61551b42f2c9fe6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dawid=20Ma=C5=82ecki?= <maleckidawid@meta.com>
Date: Mon, 23 Jun 2025 10:36:29 +0200
Subject: [PATCH 5/7] runner

---
 .github/actions/diff-js-api-breaking-changes/action.yml | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/.github/actions/diff-js-api-breaking-changes/action.yml b/.github/actions/diff-js-api-breaking-changes/action.yml
index 8ce43380312b6d..c58d63e5e8edff 100644
--- a/.github/actions/diff-js-api-breaking-changes/action.yml
+++ b/.github/actions/diff-js-api-breaking-changes/action.yml
@@ -2,11 +2,11 @@ name: diff-js-api-breaking-changes
 description: Check for breaking changes in the public React Native JS API=
 runs:
   using: composite
-  env:
-    SCRATCH_DIR: ${{ runner.temp }}/diff-js-api-breaking-changes
   steps:
     - name: Fetch snapshot from PR head
       shell: bash
+      env:
+        SCRATCH_DIR: ${{ runner.temp }}/diff-js-api-breaking-changes
       run: |
         mkdir $SCRATCH_DIR
         git fetch --depth=1 origin ${{ github.event.pull_request.head.sha }}
@@ -14,6 +14,8 @@ runs:
           || echo "" > $SCRATCH_DIR/ReactNativeApi.d.ts
     - name: Run breaking change detection
       shell: bash
+      env:
+        SCRATCH_DIR: ${{ runner.temp }}/diff-js-api-breaking-changes
       run: |
         node ./scripts/diff-api-snapshot \
         ${{ github.workspace }}/packages/react-native/ReactNativeApi.d.ts  \

From 160324ffc1bb3488873630dd32a01418d5fa1088 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dawid=20Ma=C5=82ecki?= <maleckidawid@meta.com>
Date: Mon, 23 Jun 2025 10:31:09 +0200
Subject: [PATCH 6/7] Test danger on empty commit


From 300084c7b46a8152c0d8248e21e20ea0fd57f068 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dawid=20Ma=C5=82ecki?= <maleckidawid@meta.com>
Date: Mon, 23 Jun 2025 10:44:19 +0200
Subject: [PATCH 7/7] change snapshot

---
 packages/react-native/ReactNativeApi.d.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/react-native/ReactNativeApi.d.ts b/packages/react-native/ReactNativeApi.d.ts
index 9efd0983af405d..86fe96261c7a23 100644
--- a/packages/react-native/ReactNativeApi.d.ts
+++ b/packages/react-native/ReactNativeApi.d.ts
@@ -1,5 +1,4 @@
 
 export interface ReactNativeApi {
     foo: string,
-    bar: number,
 }