chore: use lookup-only cache check to skip deps job downloads (#26314)

* fix(ci): skip yarn install in deps job when cache is hit

The Install Dependencies / Yarn install & cache step in pr.yml is primarily
for populating the cache when nothing is cached. When cache keys are found,
we can skip the actual yarn install and let the workflow carry on quickly.

This adds a skip-install-if-cache-hit parameter to the yarn-install action
that allows skipping the install when node_modules cache is hit. This is
enabled for the deps job in yarn-install.yml but not for other jobs that
actually need node_modules for their work.

Co-Authored-By: keith@cal.com <keithwillcode@gmail.com>

* fix(ci): also skip playwright install in deps job when cache is hit

Extends the skip-install-if-cache-hit parameter to the yarn-playwright-install
action as well, so both yarn install and playwright install are skipped in the
deps job when their respective caches are hit.

Co-Authored-By: keith@cal.com <keithwillcode@gmail.com>

* fix(ci): use lookup-only cache check to avoid downloading 1.2GB

When skip-install-if-cache-hit is true, use actions/cache/restore@v4 with
lookup-only: true to check if caches exist without downloading them. This
avoids downloading ~1.2GB of cache data when we just want to verify caches
exist in the deps job.

The flow is now:
1. If skip-install-if-cache-hit is true, run lookup-only checks for all caches
2. If all caches hit, skip the entire restore + install flow (no downloads)
3. If any cache misses, fall back to normal restore + install + save behavior

This optimization only applies when skip-install-if-cache-hit is set to true,
so other jobs that need node_modules continue to work normally.

Co-Authored-By: keith@cal.com <keithwillcode@gmail.com>

* Apply suggestion from @keithwillcode

* Apply suggestion from @keithwillcode

* Apply suggestion from @keithwillcode

* Apply suggestion from @keithwillcode

* fix(ci): address @cubic-dev-ai feedback on cache conditions

1. yarn-install: Add 'all-caches-check' step to compute whether all three
   caches hit (not just node_modules). This ensures we only bail out when
   everything is cached, matching the PR description.

2. yarn-playwright-install: Fix backward compatibility for install step.
   In default mode, check playwright-cache.outputs.cache-hit (the restore step).
   In skip mode, check playwright-cache-check.outputs.cache-hit (lookup-only).

Co-Authored-By: keith@cal.com <keithwillcode@gmail.com>

---------

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

.github/actions/yarn-install/action.yml

@@ -15,6 +15,10 @@ inputs:
   node_version:
     required: false
     default: v20.x
+  skip-install-if-cache-hit:
+    description: "Skip yarn install if node_modules cache is hit. Use this for jobs that only need to check that cache exists."
+    required: false
+    default: "false"
 
 runs:
   using: "composite"
@@ -29,9 +33,56 @@ runs:
       run: |
         echo "CACHE_FOLDER=$(yarn config get cacheFolder)" >> $GITHUB_OUTPUT
 
+    # When skip-install-if-cache-hit is true, first check if all caches exist without downloading (lookup-only mode)
+    # This avoids downloading ~1.2GB of cache data when we just want to verify caches exist
+    - name: Check yarn cache (lookup-only)
+      if: ${{ inputs.skip-install-if-cache-hit == 'true' }}
+      uses: actions/cache/restore@v4
+      id: yarn-download-cache-check
+      with:
+        path: ${{ steps.yarn-config.outputs.CACHE_FOLDER }}
+        key: yarn-download-cache-${{ hashFiles('yarn.lock') }}
+        lookup-only: true
+
+    - name: Check node_modules cache (lookup-only)
+      if: ${{ inputs.skip-install-if-cache-hit == 'true' }}
+      uses: actions/cache/restore@v4
+      id: yarn-nm-cache-check
+      with:
+        path: |
+          **/node_modules/
+          !**/.next/node_modules/
+        key: ${{ runner.os }}-yarn-nm-cache-${{ hashFiles('yarn.lock', '.yarnrc.yml') }}
+        lookup-only: true
+
+    - name: Check yarn install state cache (lookup-only)
+      if: ${{ inputs.skip-install-if-cache-hit == 'true' }}
+      uses: actions/cache/restore@v4
+      id: yarn-install-state-cache-check
+      with:
+        path: .yarn/ci-cache/
+        key: ${{ runner.os }}-yarn-install-state-cache-${{ hashFiles('yarn.lock', '.yarnrc.yml') }}
+        lookup-only: true
+
+    # Compute whether all caches hit (only in skip mode)
+    - name: Check if all caches hit
+      if: ${{ inputs.skip-install-if-cache-hit == 'true' }}
+      id: all-caches-check
+      shell: bash
+      run: |
+        if [[ "${{ steps.yarn-download-cache-check.outputs.cache-hit }}" == "true" && \
+              "${{ steps.yarn-nm-cache-check.outputs.cache-hit }}" == "true" && \
+              "${{ steps.yarn-install-state-cache-check.outputs.cache-hit }}" == "true" ]]; then
+          echo "all-hit=true" >> $GITHUB_OUTPUT
+        else
+          echo "all-hit=false" >> $GITHUB_OUTPUT
+        fi
+
     # Yarn rotates the downloaded cache archives, @see https://github.com/actions/setup-node/issues/325
     # Yarn cache is also reusable between arch and os.
+    # Only restore if not in skip mode, or if skip mode but any cache check missed
     - name: Restore yarn cache
+      if: ${{ inputs.skip-install-if-cache-hit != 'true' || steps.all-caches-check.outputs.all-hit != 'true' }}
       uses: actions/cache@v4
       id: yarn-download-cache
       with:
@@ -40,6 +91,7 @@ runs:
 
     # Invalidated on yarn.lock changes
     - name: Restore node_modules
+      if: ${{ inputs.skip-install-if-cache-hit != 'true' || steps.all-caches-check.outputs.all-hit != 'true' }}
       id: yarn-nm-cache
       uses: actions/cache@v4
       with:
@@ -50,6 +102,7 @@ runs:
 
     # Invalidated on yarn.lock changes
     - name: Restore yarn install state
+      if: ${{ inputs.skip-install-if-cache-hit != 'true' || steps.all-caches-check.outputs.all-hit != 'true' }}
       id: yarn-install-state-cache
       uses: actions/cache@v4
       with:
@@ -57,6 +110,7 @@ runs:
         key: ${{ runner.os }}-yarn-install-state-cache-${{ hashFiles('yarn.lock', '.yarnrc.yml') }}
 
     - name: Install dependencies
+      if: ${{ inputs.skip-install-if-cache-hit != 'true' || steps.all-caches-check.outputs.all-hit != 'true' }}
       shell: bash
       run: |
         yarn install --inline-builds

.github/actions/yarn-playwright-install/action.yml

@@ -1,5 +1,10 @@
 name: Install playwright binaries
 description: "Install playwright, cache and restore if necessary"
+inputs:
+  skip-install-if-cache-hit:
+    description: "Skip playwright install if cache is hit. Use this for jobs that only need to check that cache exists."
+    required: false
+    default: "false"
 runs:
   using: "composite"
   steps:
@@ -7,7 +12,23 @@ runs:
       shell: bash
       id: playwright-version
       run: echo "PLAYWRIGHT_VERSION=$(node -e "console.log(require('./package.json').devDependencies['@playwright/test'])")" >> $GITHUB_ENV
+
+    # When skip-install-if-cache-hit is true, first check if cache exists without downloading (lookup-only mode)
+    - name: Check playwright cache (lookup-only)
+      if: ${{ inputs.skip-install-if-cache-hit == 'true' }}
+      id: playwright-cache-check
+      uses: actions/cache/restore@v4
+      with:
+        path: |
+          ~/Library/Caches/ms-playwright
+          ~/.cache/ms-playwright
+          ${{ github.workspace }}/node_modules/playwright
+        key: ${{ runner.os }}-playwright-${{ env.PLAYWRIGHT_VERSION }}
+        lookup-only: true
+
+    # Only restore cache if not in skip mode, or if skip mode but cache check missed
     - name: Cache playwright binaries
+      if: ${{ inputs.skip-install-if-cache-hit != 'true' || steps.playwright-cache-check.outputs.cache-hit != 'true' }}
       id: playwright-cache
       uses: actions/cache@v4
       with:
@@ -16,7 +37,10 @@ runs:
           ~/.cache/ms-playwright
           ${{ github.workspace }}/node_modules/playwright
         key: ${{ runner.os }}-playwright-${{ env.PLAYWRIGHT_VERSION }}
+
+    # In default mode: run if playwright-cache missed
+    # In skip mode: run if playwright-cache-check missed (but cache restore step was also skipped)
     - name: Yarn playwright install
-      if: steps.playwright-cache.outputs.cache-hit != 'true'
+      if: ${{ (inputs.skip-install-if-cache-hit != 'true' && steps.playwright-cache.outputs.cache-hit != 'true') || (inputs.skip-install-if-cache-hit == 'true' && steps.playwright-cache-check.outputs.cache-hit != 'true') }}
       shell: bash
       run: yarn playwright install --with-deps

.github/workflows/yarn-install.yml

@@ -15,4 +15,8 @@ jobs:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/dangerous-git-checkout
       - uses: ./.github/actions/yarn-install
+        with:
+          skip-install-if-cache-hit: "true"
       - uses: ./.github/actions/yarn-playwright-install
+        with:
+          skip-install-if-cache-hit: "true"