[ci] Download build artifacts in the background during job setup (#37350)
Every downstream job in `runtime_build_and_test.yml` restored the 50 `_build_*` artifacts with `actions/download-artifact` only after setup-node, the node_modules cache restore, and any installs had completed, even though the download is independent of all of them. This change marks the download as a [background step](https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax#jobsjob_idstepsbackground) started immediately after checkout, and adds an explicit `wait: download_build` before the first step that reads `build/`. The download starts after checkout because `actions/checkout` runs `git clean`, which would wipe a previously downloaded `build/` directory. The `sizebot` job is unchanged because its base-build download also writes `./build` and would collide with a concurrent artifact restore. This only shaves of a few seconds from wall time. It's more about establishing precedent. Co-authored-by: Claude Code (kimi-k3[1m]) <noreply@anthropic.com>
Sebastian "Sebbie" Silbermann committed
Aug 25, 2026 at 09:40 UTC
5d0ccf23e49f40ac423d1951cc2744e96cc9390d
1 file changed
+123
-80
.github/workflows/runtime_build_and_test.yml
+123
-80
@@ -377,6 +377,19 @@ jobs:
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- uses: actions/checkout@v4
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with:
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ref: ${{ github.event.pull_request.head.sha || github.sha }}
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+ - name: Ensure clean build directory
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+ run: rm -rf build
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+ # The build download runs in the background while Node is set up and
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+ # node_modules is restored. The `wait` step below synchronizes on it.
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+ # It must start after checkout, whose git clean would wipe `build/`.
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+ - name: Restore archived build
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+ id: download_build
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+ uses: actions/download-artifact@v4
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+ background: true
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+ with:
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+ pattern: _build_*
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+ path: build
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+ merge-multiple: true
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- uses: actions/setup-node@v4
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with:
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node-version-file: '.nvmrc'
@@ -388,18 +401,12 @@ jobs:
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**/node_modules
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key: runtime-and-compiler-node_modules-v10-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'compiler/yarn.lock') }}
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# Don't use restore-keys here. Otherwise the cache grows indefinitely.
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- - name: Ensure clean build directory
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- run: rm -rf build
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- run: yarn install --frozen-lockfile
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if: steps.node_modules.outputs.cache-hit != 'true'
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- run: yarn --cwd compiler install --frozen-lockfile
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if: steps.node_modules.outputs.cache-hit != 'true'
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- - name: Restore archived build
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- uses: actions/download-artifact@v4
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- with:
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- pattern: _build_*
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- path: build
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- merge-multiple: true
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+ - name: Wait for archived build
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+ wait: download_build
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- name: Display structure of build
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run: ls -R build
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- run: node --version
@@ -422,6 +429,16 @@ jobs:
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- uses: actions/checkout@v4
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with:
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ref: ${{ github.event.pull_request.head.sha || github.sha }}
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+ - name: Ensure clean build directory
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+ run: rm -rf build
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+ - name: Restore archived build
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+ id: download_build
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+ uses: actions/download-artifact@v4
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+ background: true
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+ with:
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+ pattern: _build_*
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+ path: build
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+ merge-multiple: true
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- uses: actions/setup-node@v4
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with:
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node-version-file: '.nvmrc'
@@ -433,16 +450,10 @@ jobs:
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**/node_modules
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key: runtime-node_modules-v10-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
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# Don't use restore-keys here. Otherwise the cache grows indefinitely.
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- - name: Ensure clean build directory
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- run: rm -rf build
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- run: yarn install --frozen-lockfile
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if: steps.node_modules.outputs.cache-hit != 'true'
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- - name: Restore archived build
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- uses: actions/download-artifact@v4
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- with:
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- pattern: _build_*
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- path: build
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- merge-multiple: true
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+ - name: Wait for archived build
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+ wait: download_build
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- name: Display structure of build
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run: ls -R build
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- run: node --version
@@ -460,6 +471,16 @@ jobs:
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- uses: actions/checkout@v4
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with:
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ref: ${{ github.event.pull_request.head.sha || github.sha }}
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+ - name: Ensure clean build directory
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+ run: rm -rf build
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+ - name: Restore archived build
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+ id: download_build
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+ uses: actions/download-artifact@v4
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+ background: true
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+ with:
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+ pattern: _build_*
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+ path: build
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+ merge-multiple: true
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- uses: actions/setup-node@v4
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with:
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node-version-file: '.nvmrc'
@@ -471,16 +492,10 @@ jobs:
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**/node_modules
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key: runtime-node_modules-v10-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
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# Don't use restore-keys here. Otherwise the cache grows indefinitely.
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- - name: Ensure clean build directory
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- run: rm -rf build
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- run: yarn install --frozen-lockfile
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if: steps.node_modules.outputs.cache-hit != 'true'
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- - name: Restore archived build
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- uses: actions/download-artifact@v4
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- with:
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- pattern: _build_*
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- path: build
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- merge-multiple: true
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+ - name: Wait for archived build
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+ wait: download_build
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# Only used to log weight variance; the new measurement is what gets
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# saved, so removed bundles drop out instead of accumulating.
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- name: Restore previous build shard weights
@@ -547,6 +562,16 @@ jobs:
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- uses: actions/checkout@v4
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with:
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ref: ${{ github.event.pull_request.head.sha || github.sha }}
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+ - name: Ensure clean build directory
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+ run: rm -rf build
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+ - name: Restore archived build
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+ id: download_build
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+ uses: actions/download-artifact@v4
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+ background: true
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+ with:
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+ pattern: _build_*
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+ path: build
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+ merge-multiple: true
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- uses: actions/setup-node@v4
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with:
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node-version-file: '.nvmrc'
@@ -558,16 +583,10 @@ jobs:
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**/node_modules
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key: runtime-node_modules-v10-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
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# Don't use restore-keys here. Otherwise the cache grows indefinitely.
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- - name: Ensure clean build directory
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- run: rm -rf build
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- run: yarn install --frozen-lockfile
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if: steps.node_modules.outputs.cache-hit != 'true'
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- - name: Restore archived build
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- uses: actions/download-artifact@v4
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- with:
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- pattern: _build_*
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- path: build
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- merge-multiple: true
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+ - name: Wait for archived build
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+ wait: download_build
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- name: Display structure of build
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run: ls -R build
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- name: Search build artifacts for unminified errors
@@ -583,6 +602,16 @@ jobs:
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- uses: actions/checkout@v4
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with:
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ref: ${{ github.event.pull_request.head.sha || github.sha }}
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+ - name: Ensure clean build directory
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+ run: rm -rf build
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+ - name: Restore archived build
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+ id: download_build
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+ uses: actions/download-artifact@v4
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+ background: true
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+ with:
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+ pattern: _build_*
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+ path: build
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+ merge-multiple: true
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- uses: actions/setup-node@v4
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with:
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node-version-file: '.nvmrc'
@@ -594,16 +623,10 @@ jobs:
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**/node_modules
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key: runtime-node_modules-v10-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
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# Don't use restore-keys here. Otherwise the cache grows indefinitely.
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- - name: Ensure clean build directory
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- run: rm -rf build
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- run: yarn install --frozen-lockfile
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if: steps.node_modules.outputs.cache-hit != 'true'
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- - name: Restore archived build
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- uses: actions/download-artifact@v4
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- with:
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- pattern: _build_*
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- path: build
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- merge-multiple: true
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+ - name: Wait for archived build
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+ wait: download_build
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- name: Display structure of build
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run: ls -R build
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- run: yarn check-release-dependencies
@@ -616,6 +639,16 @@ jobs:
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- uses: actions/checkout@v4
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with:
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ref: ${{ github.event.pull_request.head.sha || github.sha }}
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+ - name: Ensure clean build directory
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+ run: rm -rf build
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+ - name: Restore archived build
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+ id: download_build
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+ uses: actions/download-artifact@v4
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+ background: true
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+ with:
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+ pattern: _build_*
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+ path: build
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+ merge-multiple: true
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- uses: actions/setup-node@v4
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with:
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node-version-file: '.nvmrc'
@@ -626,16 +659,10 @@ jobs:
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path: |
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**/node_modules
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key: fixtures_dom-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'fixtures/dom/yarn.lock') }}
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- - name: Ensure clean build directory
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- run: rm -rf build
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- run: yarn --cwd fixtures/dom install --frozen-lockfile
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if: steps.node_modules.outputs.cache-hit != 'true'
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- - name: Restore archived build
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- uses: actions/download-artifact@v4
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- with:
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- pattern: _build_*
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- path: build
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- merge-multiple: true
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+ - name: Wait for archived build
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+ wait: download_build
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- name: Display structure of build
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run: ls -R build
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- name: Run DOM fixture tests
@@ -655,6 +682,16 @@ jobs:
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- uses: actions/checkout@v4
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with:
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ref: ${{ github.event.pull_request.head.sha || github.sha }}
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+ - name: Ensure clean build directory
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+ run: rm -rf build
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+ - name: Restore archived build
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+ id: download_build
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+ uses: actions/download-artifact@v4
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+ background: true
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+ with:
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+ pattern: _build_*
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+ path: build
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+ merge-multiple: true
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- uses: actions/setup-node@v4
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with:
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node-version-file: '.nvmrc'
@@ -668,8 +705,6 @@ jobs:
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path: |
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**/node_modules
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key: fixtures_flight-node_modules-v6-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock', 'fixtures/flight/yarn.lock') }}
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- - name: Ensure clean build directory
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- run: rm -rf build
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- run: yarn install --frozen-lockfile
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if: steps.node_modules.outputs.cache-hit != 'true'
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- run: yarn --cwd fixtures/flight install --frozen-lockfile
@@ -687,12 +722,8 @@ jobs:
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if: steps.cache_playwright_browsers.outputs.cache-hit != 'true'
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working-directory: fixtures/flight
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run: npx playwright install --with-deps chromium
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- - name: Restore archived build
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- uses: actions/download-artifact@v4
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- with:
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- pattern: _build_*
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- path: build
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- merge-multiple: true
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+ - name: Wait for archived build
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+ wait: download_build
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- name: Display structure of build
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run: ls -R build
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- name: Run tests
@@ -727,6 +758,16 @@ jobs:
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- uses: actions/checkout@v4
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with:
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ref: ${{ github.event.pull_request.head.sha || github.sha }}
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+ - name: Ensure clean build directory
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+ run: rm -rf build
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+ - name: Restore archived build
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+ id: download_build
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+ uses: actions/download-artifact@v4
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+ background: true
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+ with:
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+ pattern: _build_*
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+ path: build
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+ merge-multiple: true
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- uses: actions/setup-node@v4
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with:
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node-version-file: '.nvmrc'
@@ -738,16 +779,10 @@ jobs:
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**/node_modules
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key: runtime-node_modules-v10-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
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# Don't use restore-keys here. Otherwise the cache grows indefinitely.
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- - name: Ensure clean build directory
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- run: rm -rf build
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- run: yarn install --frozen-lockfile
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if: steps.node_modules.outputs.cache-hit != 'true'
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- - name: Restore archived build
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- uses: actions/download-artifact@v4
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- with:
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- pattern: _build_*
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- path: build
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- merge-multiple: true
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+ - name: Wait for archived build
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+ wait: download_build
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- run: ./scripts/ci/pack_and_store_devtools_artifacts.sh ${{ matrix.browser }}
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env:
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RELEASE_CHANNEL: experimental
@@ -821,6 +856,16 @@ jobs:
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- uses: actions/checkout@v4
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with:
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ref: ${{ github.event.pull_request.head.sha || github.sha }}
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+ - name: Ensure clean build directory
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+ run: rm -rf build
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+ - name: Restore archived build
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+ id: download_build
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+ uses: actions/download-artifact@v4
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+ background: true
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+ with:
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+ pattern: _build_*
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+ path: build
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+ merge-multiple: true
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- uses: actions/setup-node@v4
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with:
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node-version-file: '.nvmrc'
@@ -832,22 +877,16 @@ jobs:
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**/node_modules
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key: runtime-node_modules-v10-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
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# Don't use restore-keys here. Otherwise the cache grows indefinitely.
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- - name: Ensure clean build directory
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- run: rm -rf build
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- run: yarn install --frozen-lockfile
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if: steps.node_modules.outputs.cache-hit != 'true'
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- - name: Restore archived build
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- uses: actions/download-artifact@v4
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- with:
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- pattern: _build_*
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- path: build
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- merge-multiple: true
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- name: Restore Playwright Chromium
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uses: actions/cache/restore@v4
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with:
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path: ~/.cache/ms-playwright
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key: playwright-browsers-v6-${{ runner.arch }}-${{ runner.os }}-${{ needs.runtime_playwright_chromium_cache.outputs.playwright_version }}
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fail-on-cache-miss: true
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+ - name: Wait for archived build
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+ wait: download_build
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- run: ./scripts/ci/run_devtools_e2e_tests.js
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env:
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RELEASE_CHANNEL: experimental
@@ -866,6 +905,16 @@ jobs:
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- uses: actions/checkout@v4
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with:
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ref: ${{ github.event.pull_request.head.sha || github.sha }}
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+ - name: Ensure clean build directory
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+ run: rm -rf build
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+ - name: Restore archived build
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+ id: download_build
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+ uses: actions/download-artifact@v4
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+ background: true
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+ with:
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+ pattern: _build_*
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+ path: build
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+ merge-multiple: true
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- uses: actions/setup-node@v4
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with:
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node-version-file: '.nvmrc'
@@ -877,16 +926,8 @@ jobs:
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**/node_modules
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key: runtime-node_modules-v10-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }}
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# Don't use restore-keys here. Otherwise the cache grows indefinitely.
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- - name: Ensure clean build directory
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- run: rm -rf build
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- run: yarn install --frozen-lockfile
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if: steps.node_modules.outputs.cache-hit != 'true'
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- - name: Restore archived build
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- uses: actions/download-artifact@v4
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- with:
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- pattern: _build_*
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- path: build
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- merge-multiple: true
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- name: Restore Playwright Chromium
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uses: actions/cache/restore@v4
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with:
@@ -898,6 +939,8 @@ jobs:
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run: |
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echo "executable_path=$(node -e 'process.stdout.write(require("playwright").chromium.executablePath())')" >> "$GITHUB_OUTPUT"
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"$(node -e 'process.stdout.write(require("playwright").chromium.executablePath())')" --version
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+ - name: Wait for archived build
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+ wait: download_build
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- name: Run React DevTools CDT MCP e2e tests
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run: yarn --cwd packages/react-devtools-cdt-mcp test:e2e:ci
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env: