Fix gradle file fetcher when included build is in submodule

gradle/lib/dependabot/gradle/file_fetcher.rb

@@ -41,6 +41,14 @@ def all_buildfiles_in_build(root_dir)
         files += subproject_buildfiles(root_dir)
         files += dependency_script_plugins(root_dir)
         files + included_builds(root_dir).
+                filter do |dir|
+                  buildfile(dir)
+                rescue Dependabot::DependencyFileNotFound
+                  # ignore included build if its is in a submodule
+                  SUPPORTED_BUILD_FILE_NAMES.
+                    map { |name| clean_join(dir, name) }.
+                    all? { |path| !file_exists_in_submodule?(path) }
+                end.
                 flat_map { |dir| all_buildfiles_in_build(dir) }
       end
 

gradle/spec/dependabot/gradle/file_fetcher_spec.rb

@@ -274,6 +274,42 @@ def stub_no_content_request(path)
             ))
         end
       end
+
+      context "when the included build is in git submodule" do
+        before do
+          stub_content_request("?ref=sha", "contents_java_with_settings.json")
+          stub_content_request("settings.gradle?ref=sha", "contents_java_settings_1_included_build.json")
+          stub_content_request("build.gradle?ref=sha", "contents_java_basic_buildfile.json")
+          stub_content_request("app/build.gradle?ref=sha", "contents_java_basic_buildfile.json")
+          stub_content_request("included?ref=sha", "contents_submodule.json")
+          stub_content_request("included/build.gradle?ref=sha", "contents_java_basic_buildfile.json")
+        end
+
+        it "fetches the main buildfile" do
+          expect(file_fetcher_instance.files.count).to eq(3)
+          expect(file_fetcher_instance.files.map(&:name)).
+            to match_array(%w(build.gradle settings.gradle app/build.gradle))
+        end
+      end
+
+      context "when the included buildfile can't be found" do
+        before do
+          stub_content_request("?ref=sha", "contents_java_with_settings.json")
+          stub_content_request("settings.gradle?ref=sha", "contents_java_settings_1_included_build.json")
+          stub_content_request("build.gradle?ref=sha", "contents_java_basic_buildfile.json")
+          stub_content_request("app/build.gradle?ref=sha", "contents_java_basic_buildfile.json")
+          stub_no_content_request("included?ref=sha")
+          stub_no_content_request("included/build.gradle?ref=sha")
+          stub_no_content_request("included/build.gradle.kts?ref=sha")
+        end
+
+        it "raises dependency file not found" do
+          expect { file_fetcher_instance.files }.to raise_error do |error|
+            expect(error).to be_a(Dependabot::DependencyFileNotFound)
+            expect(error.file_path).to eq("/included/build.gradle")
+          end
+        end
+      end
     end
 
     context "only a settings.gradle" do

gradle/spec/fixtures/github/contents_submodule.json

@@ -0,0 +1,17 @@
+{
+  "_links": {
+      "git": "https://api.github.com/repos/gocardless/bump/git/trees/sha",
+      "html": "https://github.com/gocardless/bump/tree/sha",
+      "self": "https://api.github.com/repos/gocardless/bump/contents/included?ref=main"
+  },
+  "download_url": null,
+  "git_url": "https://api.github.com/repos/gocardless/bump/git/trees/sha",
+  "html_url": "https://github.com/gocardless/bump/tree/sha",
+  "name": "included",
+  "path": "included",
+  "sha": "sha",
+  "size": 0,
+  "submodule_git_url": "https://github.com/gocardless/bump.git",
+  "type": "submodule",
+  "url": "https://api.github.com/repos/gocardless/bump/contents/included?ref=main"
+}