feat(node): mutable pull request builds (projen#624)

Introduce "mutablke builds". When enabled (by default) it will cause PR builds to automatically push any changes to synthesized files or snapshots to the PR branch. This only works for branches and will fail for forks (similar behavior to the anti-tamper check). See attached documentation. This means that if a PR is submitted and requires updates to generated files, the PR branch will automatically get updated. It also implies that anti-tamper check is disabled for PR builds. This is done as part of the PR build which means that if the build passes and changes are pushed successfully, the PR check will be successful (doing that as a result of a different workflow will not trigger the PR build). Related to projen#602 and projen#604
FitX · Mar 17, 2021 · 757f8b1 · 757f8b1
1 parent 7997b69
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Showing 12 changed files with 321 additions and 86 deletions.
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
@@ -12,6 +12,9 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v2
+        with:
+          ref: ${{ github.event.pull_request.head.ref }}
+          repository: ${{ github.event.pull_request.head.repo.full_name }}
       - name: Setup Node.js
         uses: actions/setup-node@v1
         with:
@@ -20,8 +23,6 @@ jobs:
         run: yarn install --check-files --frozen-lockfile
       - name: Synthesize project files
         run: /bin/bash ./projen.bash
-      - name: Anti-tamper check
-        run: git diff --exit-code
       - name: Set git identity
         run: |-
           git config user.name "Auto-bump"
@@ -32,7 +33,8 @@ jobs:
         uses: codecov/codecov-action@v1
         with:
           directory: coverage
-      - name: Anti-tamper check
-        run: git diff --exit-code
+      - name: Commit and push changes (if any)
+        run: 'git diff --exit-code || (git commit -am "chore: self mutation" && git push
+          origin HEAD:${{ github.event.pull_request.head.ref }})'
     container:
       image: jsii/superchain
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
@@ -41,13 +41,9 @@ jobs:
       - name: Anti-tamper check
         run: git diff --exit-code
       - name: Push commits
-        run: git push origin $BRANCH
-        env:
-          BRANCH: ${{ github.ref }}
+        run: git push origin HEAD:${{ github.ref }}
       - name: Push tags
-        run: git push --follow-tags origin $BRANCH
-        env:
-          BRANCH: ${{ github.ref }}
+        run: git push --follow-tags origin ${{ github.ref }}
       - name: Upload artifact
         uses: actions/upload-artifact@v2.1.1
         with:

diff --git a/.projenrc.js b/.projenrc.js
@@ -8,6 +8,10 @@ const project = new JsiiProject({
   authorEmail: 'benisrae@amazon.com',
   stability: 'experimental',
 
+  // this will cause PR builds to auto update the
+  // branch with changes to generated files (experimental)
+  buildWorkflowMutable: true,
+
   pullRequestTemplateContents: [
     '---',
     'By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.',

diff --git a/API.md b/API.md
diff --git a/docs/mutable-builds.md b/docs/mutable-builds.md
@@ -0,0 +1,27 @@
+# Mutable Builds
+
+Projen synthesizes files that are part of your source repository. This means
+that when you change you projenrc file, and execute `projen`, other files in
+your repo may change as a result.
+
+This is also relevant in other situations where your build process _mutates_
+your repository. For example, if you use **snapshot testing**, your repository
+includes snapshots which represent expected test results. When your code
+changes, you will likely need to update those snapshots as well.
+
+To ensure that a pull request branch always represent the final state of the
+repository, you can enable the `mutableBuild` option in your project
+configuration (currently only supported for projects derived from
+`NodeProject`).
+
+When enabled, the PR build workflow (also called `build`) will push any modified
+files to the PR branch after a successful build, so that the branch will always
+reflect the most up-to-date version of all generated files.
+
+## Forks
+
+This feature does not work for forks since it is impossible to safely push
+changes to a fork from a PR build. If a PR is created from a fork of the
+repository and there are build mutations, the PR build will fail (indicating
+that it cannot push to the fork). To fix this, the branch needs to be updated
+(same behavior as if mutable builds was disabled).
diff --git a/src/__tests__/__snapshots__/integ.test.ts.snap b/src/__tests__/__snapshots__/integ.test.ts.snap
@@ -259,6 +259,9 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v2
+        with:
+          ref: \${{ github.event.pull_request.head.ref }}
+          repository: \${{ github.event.pull_request.head.repo.full_name }}
       - name: Setup Node.js
         uses: actions/setup-node@v1
         with:
@@ -267,16 +270,15 @@ jobs:
         run: yarn install --check-files --frozen-lockfile
       - name: Synthesize project files
         run: npx projen
-      - name: Anti-tamper check
-        run: git diff --exit-code
       - name: Set git identity
         run: |-
           git config user.name \\"Auto-bump\\"
           git config user.email \\"github-actions@github.com\\"
       - name: Build
         run: npx projen build
-      - name: Anti-tamper check
-        run: git diff --exit-code
+      - name: Commit and push changes (if any)
+        run: 'git diff --exit-code || (git commit -am \\"chore: self mutation\\" && git push
+          origin HEAD:\${{ github.event.pull_request.head.ref }})'
     container:
       image: jsii/superchain
 ",
@@ -352,13 +354,9 @@ jobs:
       - name: Anti-tamper check
         run: git diff --exit-code
       - name: Push commits
-        run: git push origin $BRANCH
-        env:
-          BRANCH: \${{ github.ref }}
+        run: git push origin HEAD:\${{ github.ref }}
       - name: Push tags
-        run: git push --follow-tags origin $BRANCH
-        env:
-          BRANCH: \${{ github.ref }}
+        run: git push --follow-tags origin \${{ github.ref }}
       - name: Upload artifact
         uses: actions/upload-artifact@v2.1.1
         with:
@@ -4119,20 +4117,22 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v2
+        with:
+          ref: \${{ github.event.pull_request.head.ref }}
+          repository: \${{ github.event.pull_request.head.repo.full_name }}
       - name: Install dependencies
         run: pnpm i --frozen-lockfile
       - name: Synthesize project files
         run: npx projen
-      - name: Anti-tamper check
-        run: git diff --exit-code
       - name: Set git identity
         run: |-
           git config user.name \\"Auto-bump\\"
           git config user.email \\"github-actions@github.com\\"
       - name: Build
         run: npx projen build
-      - name: Anti-tamper check
-        run: git diff --exit-code
+      - name: Commit and push changes (if any)
+        run: 'git diff --exit-code || (git commit -am \\"chore: self mutation\\" && git push
+          origin HEAD:\${{ github.event.pull_request.head.ref }})'
 ",
   ".github/workflows/release.yml": "# ~~ Generated by projen. To modify, edit .projenrc.js and run \\"npx projen\\".
 
@@ -4169,13 +4169,9 @@ jobs:
       - name: Anti-tamper check
         run: git diff --exit-code
       - name: Push commits
-        run: git push origin $BRANCH
-        env:
-          BRANCH: \${{ github.ref }}
+        run: git push origin HEAD:\${{ github.ref }}
       - name: Push tags
-        run: git push --follow-tags origin $BRANCH
-        env:
-          BRANCH: \${{ github.ref }}
+        run: git push --follow-tags origin \${{ github.ref }}
       - name: Upload artifact
         uses: actions/upload-artifact@v2.1.1
         with:

diff --git a/src/__tests__/__snapshots__/inventory.test.ts.snap b/src/__tests__/__snapshots__/inventory.test.ts.snap
@@ -629,6 +629,18 @@ Array [
         "switch": "min-node-version",
         "type": "string",
       },
+      Object {
+        "default": "true",
+        "docs": "Automatically update files modified during builds to pull-request branches.",
+        "name": "mutableBuild",
+        "optional": true,
+        "parent": "NodeProjectOptions",
+        "path": Array [
+          "mutableBuild",
+        ],
+        "switch": "mutable-build",
+        "type": "boolean",
+      },
       Object {
         "default": "$BASEDIR",
         "docs": "This is the name of your project.",
@@ -1802,6 +1814,18 @@ Array [
         "switch": "min-node-version",
         "type": "string",
       },
+      Object {
+        "default": "true",
+        "docs": "Automatically update files modified during builds to pull-request branches.",
+        "name": "mutableBuild",
+        "optional": true,
+        "parent": "NodeProjectOptions",
+        "path": Array [
+          "mutableBuild",
+        ],
+        "switch": "mutable-build",
+        "type": "boolean",
+      },
       Object {
         "default": "$BASEDIR",
         "docs": "This is the name of your project.",
@@ -2927,6 +2951,18 @@ Array [
         "switch": "min-node-version",
         "type": "string",
       },
+      Object {
+        "default": "true",
+        "docs": "Automatically update files modified during builds to pull-request branches.",
+        "name": "mutableBuild",
+        "optional": true,
+        "parent": "NodeProjectOptions",
+        "path": Array [
+          "mutableBuild",
+        ],
+        "switch": "mutable-build",
+        "type": "boolean",
+      },
       Object {
         "default": "$BASEDIR",
         "docs": "This is the name of your project.",
@@ -4354,6 +4390,18 @@ Array [
         "switch": "min-node-version",
         "type": "string",
       },
+      Object {
+        "default": "true",
+        "docs": "Automatically update files modified during builds to pull-request branches.",
+        "name": "mutableBuild",
+        "optional": true,
+        "parent": "NodeProjectOptions",
+        "path": Array [
+          "mutableBuild",
+        ],
+        "switch": "mutable-build",
+        "type": "boolean",
+      },
       Object {
         "default": "$BASEDIR",
         "docs": "This is the name of your project.",
@@ -5364,6 +5412,18 @@ Array [
         "switch": "min-node-version",
         "type": "string",
       },
+      Object {
+        "default": "true",
+        "docs": "Automatically update files modified during builds to pull-request branches.",
+        "name": "mutableBuild",
+        "optional": true,
+        "parent": "NodeProjectOptions",
+        "path": Array [
+          "mutableBuild",
+        ],
+        "switch": "mutable-build",
+        "type": "boolean",
+      },
       Object {
         "default": "$BASEDIR",
         "docs": "This is the name of your project.",
@@ -6413,6 +6473,18 @@ Array [
         "switch": "min-node-version",
         "type": "string",
       },
+      Object {
+        "default": "true",
+        "docs": "Automatically update files modified during builds to pull-request branches.",
+        "name": "mutableBuild",
+        "optional": true,
+        "parent": "NodeProjectOptions",
+        "path": Array [
+          "mutableBuild",
+        ],
+        "switch": "mutable-build",
+        "type": "boolean",
+      },
       Object {
         "default": "$BASEDIR",
         "docs": "This is the name of your project.",
@@ -7401,6 +7473,18 @@ Array [
         "switch": "min-node-version",
         "type": "string",
       },
+      Object {
+        "default": "true",
+        "docs": "Automatically update files modified during builds to pull-request branches.",
+        "name": "mutableBuild",
+        "optional": true,
+        "parent": "NodeProjectOptions",
+        "path": Array [
+          "mutableBuild",
+        ],
+        "switch": "mutable-build",
+        "type": "boolean",
+      },
       Object {
         "default": "$BASEDIR",
         "docs": "This is the name of your project.",
@@ -8790,6 +8874,18 @@ Array [
         "switch": "min-node-version",
         "type": "string",
       },
+      Object {
+        "default": "true",
+        "docs": "Automatically update files modified during builds to pull-request branches.",
+        "name": "mutableBuild",
+        "optional": true,
+        "parent": "NodeProjectOptions",
+        "path": Array [
+          "mutableBuild",
+        ],
+        "switch": "mutable-build",
+        "type": "boolean",
+      },
       Object {
         "default": "$BASEDIR",
         "docs": "This is the name of your project.",
@@ -9815,6 +9911,18 @@ Array [
         "switch": "min-node-version",
         "type": "string",
       },
+      Object {
+        "default": "true",
+        "docs": "Automatically update files modified during builds to pull-request branches.",
+        "name": "mutableBuild",
+        "optional": true,
+        "parent": "NodeProjectOptions",
+        "path": Array [
+          "mutableBuild",
+        ],
+        "switch": "mutable-build",
+        "type": "boolean",
+      },
       Object {
         "default": "$BASEDIR",
         "docs": "This is the name of your project.",
@@ -10887,6 +10995,18 @@ Array [
         "switch": "min-node-version",
         "type": "string",
       },
+      Object {
+        "default": "true",
+        "docs": "Automatically update files modified during builds to pull-request branches.",
+        "name": "mutableBuild",
+        "optional": true,
+        "parent": "NodeProjectOptions",
+        "path": Array [
+          "mutableBuild",
+        ],
+        "switch": "mutable-build",
+        "type": "boolean",
+      },
       Object {
         "default": "$BASEDIR",
         "docs": "This is the name of your project.",
@@ -11959,6 +12079,18 @@ Array [
         "switch": "min-node-version",
         "type": "string",
       },
+      Object {
+        "default": "true",
+        "docs": "Automatically update files modified during builds to pull-request branches.",
+        "name": "mutableBuild",
+        "optional": true,
+        "parent": "NodeProjectOptions",
+        "path": Array [
+          "mutableBuild",
+        ],
+        "switch": "mutable-build",
+        "type": "boolean",
+      },
       Object {
         "default": "$BASEDIR",
         "docs": "This is the name of your project.",