Try to find pnpm-lock.yaml file upwards on tree structure

npm_and_yarn/lib/dependabot/npm_and_yarn/file_fetcher.rb

@@ -245,6 +245,20 @@ def pnpm_lock
         return @pnpm_lock if defined?(@pnpm_lock)
 
         @pnpm_lock ||= T.let(fetch_file_if_present(PNPMPackageManager::LOCKFILE_NAME), T.nilable(DependencyFile))
+
+        return @pnpm_lock if @pnpm_lock || directory == "/"
+
+        # Loop through parent directories looking for a pnpm-lock
+        (1..directory.split("/").count).each do |i|
+          @pnpm_lock = fetch_file_from_host(("../" * i) + PNPMPackageManager::LOCKFILE_NAME)
+                       .tap { |f| f.support_file = true }
+          break if @pnpm_lock
+        rescue Dependabot::DependencyFileNotFound
+          # Ignore errors (pnpm_lock.yaml may not be present)
+          nil
+        end
+
+        @pnpm_lock
       end
 
       sig { returns(T.nilable(DependencyFile)) }

npm_and_yarn/spec/dependabot/npm_and_yarn/file_fetcher_spec.rb

@@ -331,6 +331,62 @@
         .to_return(status: 404)
     end
 
+    context "when source points to nested project" do
+      let(:repo) { "dependabot-fixtures/projects/pnpm/workspace_v9" }
+      let(:directory) { "/packages/package1" }
+
+      before do
+        stub_request(:get, File.join(url, "packages/package1?ref=sha"))
+          .with(headers: { "Authorization" => "token token" })
+          .to_return(
+            status: 200,
+            body: fixture("github", "contents_js_pnpm_workspace.json"),
+            headers: json_header
+          )
+        stub_request(:get, File.join(url, "packages/package1/package.json?ref=sha"))
+          .with(headers: { "Authorization" => "token token" })
+          .to_return(
+            status: 200,
+            body: fixture("github", "package_json_content.json"),
+            headers: json_header
+          )
+        # FileFetcher will iterate trying to find `.npmrc` upwards in the folder tree
+        stub_request(:get, File.join(url, "packages/.npmrc?ref=sha"))
+          .with(headers: { "Authorization" => "token token" })
+          .to_return(
+            status: 404,
+            body: nil,
+            headers: json_header
+          )
+        stub_request(:get, File.join(url, ".npmrc?ref=sha"))
+          .with(headers: { "Authorization" => "token token" })
+          .to_return(
+            status: 200,
+            body: fixture("github", "package_json_content.json"),
+            headers: json_header
+          )
+        # FileFetcher will iterate trying to find `pnpm-lock.yaml` upwards in the folder tree
+        stub_request(:get, File.join(url, "packages/pnpm-lock.yaml?ref=sha"))
+          .with(headers: { "Authorization" => "token token" })
+          .to_return(
+            status: 404,
+            body: nil,
+            headers: json_header
+          )
+        stub_request(:get, File.join(url, "pnpm-lock.yaml?ref=sha"))
+          .with(headers: { "Authorization" => "token token" })
+          .to_return(
+            status: 200,
+            body: fixture("github", "pnpm_lock_quotes_content.json"),
+            headers: json_header
+          )
+      end
+
+      it "fetches the pnpm-lock.yaml file at the root of the monorepo" do
+        expect(file_fetcher_instance.files.map(&:name)).to include("../../pnpm-lock.yaml")
+      end
+    end
+
     context "when using older than 5.4 lockfile format" do
       before do
         stub_request(:get, File.join(url, "pnpm-lock.yaml?ref=sha"))
@@ -1195,6 +1251,12 @@
             ".yarnrc?ref=sha"
           ).with(headers: { "Authorization" => "token token" })
             .to_return(status: 404)
+          stub_request(
+            :get,
+            "https://api.github.com/repos/gocardless/bump/contents/" \
+            "pnpm-lock.yaml?ref=sha"
+          ).with(headers: { "Authorization" => "token token" })
+            .to_return(status: 404)
         end
 
         it "fetches package.json from the workspace dependencies" do
@@ -1758,6 +1820,12 @@
             ".yarnrc?ref=sha"
           ).with(headers: { "Authorization" => "token token" })
             .to_return(status: 404)
+          stub_request(
+            :get,
+            "https://api.github.com/repos/gocardless/bump/contents/" \
+            "pnpm-lock.yaml?ref=sha"
+          ).with(headers: { "Authorization" => "token token" })
+            .to_return(status: 404)
         end
 
         it "fetches package.json from the workspace dependencies" do

npm_and_yarn/spec/fixtures/github/contents_js_pnpm_workspace.json

@@ -0,0 +1,18 @@
+[
+  {
+    "name": "package.json",
+    "path": "package.json",
+    "sha": "58166807d223462b6b44dd016e0b31edb390d3f4",
+    "size": 329,
+    "url": "https://api.github.com/repos/org/repo/contents/package.json?ref=main",
+    "html_url": "https://github.com/org/repo/blob/main/package.json",
+    "git_url": "https://api.github.com/repos/org/repo/git/blobs/58166807d223462b6b44dd016e0b31edb390d3f4",
+    "download_url": "https://raw.githubusercontent.com/org/repo/main/package.json?token=ABMwe0apDiKCctWHnEHnszRBAebVHjQnks5WJWD9wA%3D%3D",
+    "type": "file",
+    "_links": {
+      "self": "https://api.github.com/repos/org/repo/contents/package.json?ref=main",
+      "git": "https://api.github.com/repos/org/repo/git/blobs/58166807d223462b6b44dd016e0b31edb390d3f4",
+      "html": "https://github.com/org/repo/blob/main/package.json"
+    }
+  }
+]