Skip pruning for pnpm workspaces since it's not supported (#1295)

* Skip pruning for pnpm workspaces since it's not supported

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## [Unreleased]
 
+- Skip pruning for pnpm workspace applications. ([#1295](https://github.com/heroku/heroku-buildpack-nodejs/pull/1295))
 
 ## [v258] - 2024-07-10
 

lib/dependencies.sh

@@ -352,6 +352,10 @@ pnpm_prune_devdependencies() {
     echo "Skipping because PNPM_SKIP_PRUNING is '$PNPM_SKIP_PRUNING'"
     meta_set "skipped-prune" "true"
     return 0
+  elif [ -f "$build_dir/pnpm-workspace.yaml" ] || [ -f "$build_dir/pnpm-workspace.yml" ]; then
+    echo "Skipping because pruning is not supported for pnpm workspaces (https://pnpm.io/cli/prune)"
+    meta_set "skipped-prune" "true"
+    return 0
   fi
 
   pnpm_version=$(pnpm --version)

test/fixtures/pnpm-workspace-binaries/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "pnpm-workspace-binaries",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "build": "pnpm -r build"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "packageManager": "[email protected]+sha256.dbdf5961c32909fb030595a9daa1dae720162e658609a8f92f2fa99835510ca5",
+  "engines": {
+    "node": "20.x"
+  }
+}

test/fixtures/pnpm-workspace-binaries/packages/one/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "one",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "build": "next --version"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "next": "15.0.0-rc.0"
+  }
+}

test/fixtures/pnpm-workspace-binaries/packages/two/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "two",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "build": "next --version"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "next": "15.0.0-rc.0"
+  }
+}