feat(blob): add support for Rust Cargo.toml vizualisation

Gemfile

@@ -457,7 +457,7 @@ gem 'grpc', '~> 1.24.0'
 
 gem 'google-protobuf', '~> 3.8.0'
 
-gem 'toml-rb', '~> 1.0.0', require: false
+gem 'toml-rb', '~> 1.0.0'
 
 # Feature toggles
 gem 'flipper', '~> 0.17.1'

app/models/blob.rb

@@ -49,6 +49,7 @@ class Blob < SimpleDelegator
     BlobViewer::Contributing,
     BlobViewer::Changelog,
 
+    BlobViewer::CargoToml,
     BlobViewer::Cartfile,
     BlobViewer::ComposerJson,
     BlobViewer::Gemfile,

app/models/blob_viewer/cargo_toml.rb

+# frozen_string_literal: true
+
+module BlobViewer
+  class CargoToml < DependencyManager
+    include Static
+
+    self.file_types = %i(cargo_toml)
+
+    def manager_name
+      'Cargo'
+    end
+
+    def manager_url
+      'https://crates.io/'
+    end
+  end
+end

lib/gitlab/dependency_linker.rb

@@ -12,7 +12,8 @@ module Gitlab
       PodspecJsonLinker,
       CartfileLinker,
       GodepsJsonLinker,
-      RequirementsTxtLinker
+      RequirementsTxtLinker,
+      CargoTomlLinker
     ].freeze
 
     def self.linker(blob_name)

lib/gitlab/dependency_linker/cargo_toml_linker.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module DependencyLinker
+    class CargoTomlLinker < BaseLinker
+      self.file_type = :cargo_toml
+
+      def link
+        return highlighted_text unless toml
+
+        super
+      end
+
+      private
+
+      def link_dependencies
+        link_dependencies_at("dependencies")
+        link_dependencies_at("dev-dependencies")
+        link_dependencies_at("build-dependencies")
+      end
+
+      def link_dependencies_at(type)
+        dependencies = toml[type]
+        return unless dependencies
+
+        dependencies.each do |name, value|
+          link_toml(name, value, type) do |name|
+            "https://crates.io/crates/#{name}"
+          end
+        end
+      end
+
+      def link_toml(key, value, type, &url_proc)
+        if value.is_a? String
+          link_regex(/^(?<name>#{key})\s*=\s*"#{value}"/, &url_proc)
+        else
+          link_regex(/^\[#{type}\.(?<name>#{key})]/, &url_proc)
+        end
+      end
+
+      def toml
+        @toml ||= TomlRB.parse(plain_text) rescue nil
+      end
+    end
+  end
+end

lib/gitlab/file_detector.rb

@@ -25,6 +25,7 @@ module Gitlab
       route_map: '.gitlab/route-map.yml',
 
       # Dependency files
+      cargo_toml: 'Cargo.toml',
       cartfile: %r{\ACartfile[^/]*\z},
       composer_json: 'composer.json',
       gemfile: /\A(Gemfile|gems\.rb)\z/,

spec/lib/gitlab/dependency_linker/cargo_toml_linker_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::DependencyLinker::CargoTomlLinker do
+  describe '.support?' do
+    it 'supports Cargo.toml' do
+      expect(described_class.support?('Cargo.toml')).to be_truthy
+    end
+
+    it 'does not support other files' do
+      expect(described_class.support?('cargo.yaml')).to be_falsey
+    end
+  end
+
+  describe '#link' do
+    let(:file_name) { "Cargo.toml" }
+
+    let(:file_content) do
+      <<-CONTENT.strip_heredoc
+        # See https://doc.rust-lang.org/cargo/reference/manifest.html
+        [package]
+        # Package shouldn't be matched
+        name = "gitlab-test"
+        version = "0.0.1"
+        authors = ["Some User <some.user@example.org>"]
+        description = "A GitLab test Cargo.toml."
+        keywords = ["gitlab", "test", "rust", "crago"]
+        readme = "README.md"
+
+        [dependencies]
+        # Default dependencies format with fixed version and version range
+        chrono = "0.4.7"
+        xml-rs = ">=0.8.0"
+
+        [dependencies.memchr]
+        # Specific dependency with optional info
+        version = "2.2.1"
+        optional = true
+
+        [dev-dependencies]
+        # Dev dependency with version modifier
+        commandspec = "~0.12.2"
+
+        [build-dependencies]
+        # Build dependency with version wildcard
+        thread_local = "0.3.*"
+      CONTENT
+    end
+
+    subject { Gitlab::Highlight.highlight(file_name, file_content) }
+
+    def link(name, url)
+      %{<a href="#{url}" rel="nofollow noreferrer noopener" target="_blank">#{name}</a>}
+    end
+
+    it 'links dependencies' do
+      expect(subject).to include(link('chrono', 'https://crates.io/crates/chrono'))
+      expect(subject).to include(link('xml-rs', 'https://crates.io/crates/xml-rs'))
+      expect(subject).to include(link('memchr', 'https://crates.io/crates/memchr'))
+      expect(subject).to include(link('commandspec', 'https://crates.io/crates/commandspec'))
+      expect(subject).to include(link('thread_local', 'https://crates.io/crates/thread_local'))
+    end
+
+    it 'does not contain metadata identified as package' do
+      expect(subject).not_to include(link('version', 'https://crates.io/crates/version'))
+    end
+  end
+end

spec/lib/gitlab/dependency_linker_spec.rb

@@ -83,5 +83,13 @@ describe Gitlab::DependencyLinker do
 
       described_class.link(blob_name, nil, nil)
     end
+
+    it 'links using CargoTomlLinker' do
+      blob_name = 'Cargo.toml'
+
+      expect(described_class::CargoTomlLinker).to receive(:link)
+
+      described_class.link(blob_name, nil, nil)
+    end
   end
 end