From e01914bffac3571e32dd9b19b000dfeed590d63f Mon Sep 17 00:00:00 2001
From: Michael Suchacz <203725896+ibetitsmike@users.noreply.github.com>
Date: Tue, 9 Dec 2025 12:43:24 +0000
Subject: [PATCH] =?UTF-8?q?=F0=9F=A4=96=20perf:=20skip=20redundant=20bun?=
 =?UTF-8?q?=20cache=20restore=20when=20node=5Fmodules=20exists?=
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The previous logic checked cache-hit output which is false for partial
restore-key matches. This caused Windows builds to unnecessarily:

1. Download and decompress the 275MB bun install cache (~88 seconds)
2. Run bun install (which was a no-op since node_modules existed)
3. Re-save both caches at job end (~77 seconds)

The fix checks if node_modules/.bin actually exists after cache restore,
which is more reliable than the cache-hit output for determining if we
need to install dependencies.

Expected time savings: ~88-165 seconds on Windows builds (was ~8m, should
be ~6m or less).

_Generated with mux_
---
 .github/actions/setup-mux/action.yml | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/.github/actions/setup-mux/action.yml b/.github/actions/setup-mux/action.yml
index 284be5341f..3997d451a6 100644
--- a/.github/actions/setup-mux/action.yml
+++ b/.github/actions/setup-mux/action.yml
@@ -22,8 +22,20 @@ runs:
         restore-keys: |
           ${{ runner.os }}-${{ runner.arch }}-bun-${{ steps.bun-version.outputs.version }}-node-modules-
 
+    - name: Check if node_modules exists
+      id: check-node-modules
+      shell: bash
+      run: |
+        if [ -d "node_modules" ] && [ -d "node_modules/.bin" ]; then
+          echo "exists=true" >> $GITHUB_OUTPUT
+        else
+          echo "exists=false" >> $GITHUB_OUTPUT
+        fi
+
+    # Only restore bun install cache when node_modules is completely missing.
+    # This avoids 88+ seconds of tar/zstd decompression on Windows for partial cache hits.
     - name: Cache bun install cache
-      if: steps.cache-node-modules.outputs.cache-hit != 'true'
+      if: steps.check-node-modules.outputs.exists != 'true'
       id: cache-bun-install
       uses: actions/cache@v4
       with:
@@ -33,6 +45,6 @@ runs:
           ${{ runner.os }}-bun-cache-
 
     - name: Install dependencies
-      if: steps.cache-node-modules.outputs.cache-hit != 'true'
+      if: steps.check-node-modules.outputs.exists != 'true'
       shell: bash
       run: bun install --frozen-lockfile