Add test for file updater vendoring

Author: jurre

.gitignore

@@ -4,8 +4,10 @@
 /tmp
 /pkg
 /dependabot-*.gem
+!bundler/spec/fixtures/projects/**/Gemfile.lock
 Gemfile.lock
 vendor
+!bundler/spec/fixtures/vendored_gems/vendor
 .DS_Store
 *.pyc
 *git.store
@@ -19,4 +21,4 @@ vendor
 /npm_and_yarn/helpers/install-dir
 /dry-run
 **/bin/helper
-/.core-bash_history
+/.core-bash_history

bundler/.gitignore

@@ -3,3 +3,5 @@
 /tmp
 /dependabot-*.gem
 Gemfile.lock
+!spec/fixtures/projects/**/Gemfile.lock
+!spec/fixtures/projects/**/vendor

bundler/spec/dependabot/bundler/file_updater_spec.rb

@@ -19,7 +19,8 @@
       credentials: [{
         "type" => "git_source",
         "host" => "github.com"
-      }]
+      }],
+      repo_contents_path: repo_contents_path
     )
   end
   let(:dependencies) { [dependency] }
@@ -63,6 +64,7 @@
     [{ file: "Gemfile", requirement: "~> 1.4.0", groups: [], source: nil }]
   end
   let(:tmp_path) { Dependabot::SharedHelpers::BUMP_TMP_DIR_PATH }
+  let(:repo_contents_path) { nil }
 
   before { Dir.mkdir(tmp_path) unless Dir.exist?(tmp_path) }
 
@@ -1540,5 +1542,48 @@
         expect { updater }.to raise_error(/Gemfile must be provided/)
       end
     end
+
+    context "vendoring" do
+      let(:repo_contents_path) { build_tmp_repo("vendored_gems") }
+
+      before do
+        stub_request(:get, "https://rubygems.org/gems/business-1.5.0.gem").
+          to_return(
+            status: 200,
+            body: fixture("ruby", "gems", "business-1.5.0.gem")
+          )
+      end
+
+      after do
+        FileUtils.remove_entry repo_contents_path
+      end
+
+      it "vendors the new dependency" do
+        expect(updater.updated_dependency_files.map(&:name)).to match_array(
+          [
+            "vendor/cache/business-1.4.0.gem",
+            "vendor/cache/business-1.5.0.gem",
+            "Gemfile",
+            "Gemfile.lock"
+          ]
+        )
+      end
+
+      it "base64 encodes vendored gems" do
+        file = updater.updated_dependency_files.find do |f|
+          f.name == "vendor/cache/business-1.5.0.gem"
+        end
+
+        expect(file.content_encoding).to eq("base64")
+      end
+
+      it "deletes the old vendored gem" do
+        file = updater.updated_dependency_files.find do |f|
+          f.name == "vendor/cache/business-1.4.0.gem"
+        end
+
+        expect(file.deleted?).to eq true
+      end
+    end
   end
 end

bundler/spec/fixtures/projects/vendored_gems/Gemfile

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+source "https://rubygems.org"
+
+gem "business", "~> 1.4.0"
+gem "statesman", "~> 1.2.0"

bundler/spec/fixtures/projects/vendored_gems/Gemfile.lock

@@ -0,0 +1,15 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    business (1.4.0)
+    statesman (1.2.1)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  business (~> 1.4.0)
+  statesman (~> 1.2.0)
+
+BUNDLED WITH
+   1.10.6

bundler/spec/fixtures/projects/vendored_gems/vendor/cache/business-1.4.0.gem

@@ -36,6 +36,47 @@ def fixture(*name)
   File.read(File.join("spec", "fixtures", File.join(*name)))
 end
 
+# Creates a temporary directory and copies in any files from the specified
+# project path. The project path will typically contain a dependency file and a
+# lockfile, but it may also include a vendor directory. A git repo will be
+# initialized in the tmp directory.
+#
+# @param project [String] the project directory, located in
+# "spec/fixtures/projects"
+# @return [String] the path to the new temp repo.
+def build_tmp_repo(project)
+  project_path = File.expand_path(File.join("spec/fixtures/projects", project))
+
+  tmp_dir = Dependabot::SharedHelpers::BUMP_TMP_DIR_PATH
+  prefix = Dependabot::SharedHelpers::BUMP_TMP_FILE_PREFIX
+  Dir.mkdir(tmp_dir) unless Dir.exist?(tmp_dir)
+  dir = Dir.mktmpdir(prefix, tmp_dir)
+  path = Pathname.new(dir).expand_path
+  FileUtils.mkpath(path)
+
+  FileUtils.cp_r("#{project_path}/.", path)
+
+  Dir.chdir(path) do
+    Dependabot::SharedHelpers.run_shell_command(
+      <<~CMD
+        git config --global user.name || \
+          git config --global user.email no-reply@github.com
+      CMD
+    )
+    Dependabot::SharedHelpers.run_shell_command(
+      <<~CMD
+        git config --global user.name || \
+          git config --global user.name dependabot-ci
+      CMD
+    )
+    Dependabot::SharedHelpers.run_shell_command("git init")
+    Dependabot::SharedHelpers.run_shell_command("git add --all")
+    Dependabot::SharedHelpers.run_shell_command("git commit -m 'Init'")
+  end
+
+  path
+end
+
 def capture_stderr
   previous_stderr = $stderr
   $stderr = StringIO.new