Add GitHub file links with line numbers to Slack messages

lib/smart_todo.rb

@@ -10,6 +10,7 @@ module SmartTodo
   autoload :Todo,                     "smart_todo/todo"
   autoload :CommentParser,            "smart_todo/comment_parser"
   autoload :HttpClientBuilder,        "smart_todo/http_client_builder"
+  autoload :GitUtils,                 "smart_todo/git_utils"
 
   module Dispatchers
     autoload :Base,                   "smart_todo/dispatchers/base"

lib/smart_todo/comment_parser.rb

@@ -59,7 +59,8 @@ def parse_comments(comments, filepath)
 
         if source.match?(TAG_PATTERN)
           todos << current_todo if current_todo
-          current_todo = Todo.new(source, filepath)
+          line_number = comment.location.start_line
+          current_todo = Todo.new(source, filepath, line_number)
         elsif current_todo && (indent = source[/^#(\s*)/, 1].length) && (indent - current_todo.indent == 2)
           current_todo << "#{source[(indent + 1)..]}\n"
         else

lib/smart_todo/dispatchers/base.rb

@@ -65,10 +65,12 @@ def slack_message(user, assignee)
           existing_user
         end
 
+        file_reference = generate_file_reference
+
         <<~EOM
           #{header}
 
-          You have an assigned TODO in the `#{@file}` file#{repo}.
+          You have an assigned TODO#{file_reference}#{repo}.
           #{@event_message}
 
           Here is the associated comment on your TODO:
@@ -79,6 +81,33 @@ def slack_message(user, assignee)
         EOM
       end
 
+      # Generates a file reference with link (if in a GitHub repo) or readable line reference
+      #
+      # @return [String]
+      def generate_file_reference
+        # Find the git repository root from the file's path, not from Dir.pwd
+        # This ensures we detect the correct repo even when smart_todo is run
+        # from a different directory than the repo root
+        git_root = GitUtils.find_git_root(@file)
+
+        # Try to generate a GitHub link if we have a line number and found a git repo
+        if @todo_node.line_number && git_root
+          github_link = GitUtils.generate_github_link(@file, @todo_node.line_number, git_root)
+
+          if github_link
+            " at <#{github_link}|#{@file}:#{@todo_node.line_number}>"
+          else
+            " in the `#{@file}` file on line #{@todo_node.line_number}"
+          end
+        elsif @todo_node.line_number
+          # Have line number but no git repo
+          " in the `#{@file}` file on line #{@todo_node.line_number}"
+        else
+          # Fallback to just the file name if no line number
+          " in the `#{@file}` file"
+        end
+      end
+
       # Message in case a TODO's assignee doesn't exist in the Slack organization
       #
       # @param user [Hash]

lib/smart_todo/git_utils.rb

@@ -0,0 +1,145 @@
+# frozen_string_literal: true
+
+module SmartTodo
+  module GitUtils
+    class << self
+      # Finds the git repository root by walking up the directory tree from the given path
+      # Returns the path to the directory containing .git, or nil if not found
+      #
+      # @param start_path [String] the starting directory path (usually from a file)
+      # @return [String, nil] the git repository root path, or nil if not in a git repo
+      def find_git_root(start_path)
+        # Normalize to absolute path and use directory if it's a file
+        path = File.expand_path(start_path)
+        path = File.dirname(path) if File.file?(path)
+
+        # Check cache first
+        return git_root_cache[path] if git_root_cache.key?(path)
+
+        # Walk up the directory tree looking for .git
+        current_path = path
+        loop do
+          git_dir = File.join(current_path, ".git")
+          if File.exist?(git_dir)
+            git_root_cache[path] = current_path
+            return current_path
+          end
+
+          parent = File.dirname(current_path)
+          # Reached filesystem root without finding .git
+          if parent == current_path
+            git_root_cache[path] = nil
+            return
+          end
+
+          current_path = parent
+        end
+      end
+
+      # Detects if the current directory is a git repository
+      # and extracts the GitHub organization and repository name
+      # Returns: { org: "Shopify", repo: "smart_todo", url: "https://github.com/Shopify/smart_todo" }
+      # Returns nil if not a git repository or cannot parse GitHub URL
+      #
+      # @param base_path [String] the directory path to check (defaults to Dir.pwd)
+      # @return [Hash, nil] GitHub info hash or nil
+      def github_info(base_path = Dir.pwd)
+        # Normalize path
+        base_path = File.expand_path(base_path)
+
+        # Check cache first
+        return git_info_cache[base_path] if git_info_cache.key?(base_path)
+
+        git_config = File.join(base_path, ".git", "config")
+        unless File.exist?(git_config)
+          git_info_cache[base_path] = nil
+          return
+        end
+
+        config_content = File.read(git_config)
+        remote_url = parse_remote_url(config_content)
+        unless remote_url
+          git_info_cache[base_path] = nil
+          return
+        end
+
+        result = parse_github_url(remote_url)
+        git_info_cache[base_path] = result
+        result
+      end
+
+      # Generates a GitHub file link with line number
+      # e.g., https://github.com/Shopify/smart_todo/blob/main/lib/todo.rb#L42
+      def generate_github_link(filepath, line_number, base_path = Dir.pwd)
+        github_info = github_info(base_path)
+        return unless github_info
+
+        # Convert absolute path to relative path from repo root
+        relative_path = if filepath.start_with?(base_path)
+          filepath.sub("#{base_path}/", "")
+        else
+          filepath
+        end
+
+        # Get the default branch (typically main)
+        branch = default_branch(base_path) || "main"
+
+        "#{github_info[:url]}/blob/#{branch}/#{relative_path}#L#{line_number}"
+      end
+
+      private
+
+      # Cache accessors - use methods instead of instance variables for thread safety
+      def git_root_cache
+        @git_root_cache ||= {}
+      end
+
+      def git_info_cache
+        @git_info_cache ||= {}
+      end
+
+      # Parses the git config file to extract the remote origin URL
+      def parse_remote_url(config_content)
+        # Match both HTTPS and SSH formats:
+        # - https://github.com/Shopify/smart_todo.git
+        # - git@github.com:Shopify/smart_todo.git
+        if config_content =~ %r{url\s*=\s*(https://github\.com/[^\s]+|git@github\.com:[^\s]+)}
+          ::Regexp.last_match(1)
+        end
+      end
+
+      # Parses a GitHub URL (HTTPS or SSH) and extracts org/repo info
+      def parse_github_url(remote_url)
+        case remote_url
+        when %r{https://github\.com/([^/]+)/([^/\s]+?)(?:\.git)?$}
+          org = ::Regexp.last_match(1)
+          repo = ::Regexp.last_match(2)
+          {
+            org: org,
+            repo: repo,
+            url: "https://github.com/#{org}/#{repo}",
+          }
+        when %r{git@github\.com:([^/]+)/([^/\s]+?)(?:\.git)?$}
+          org = ::Regexp.last_match(1)
+          repo = ::Regexp.last_match(2)
+          {
+            org: org,
+            repo: repo,
+            url: "https://github.com/#{org}/#{repo}",
+          }
+        end
+      end
+
+      # Gets the default branch name from HEAD reference
+      def default_branch(base_path)
+        head_file = File.join(base_path, ".git", "HEAD")
+        return unless File.exist?(head_file)
+
+        head_content = File.read(head_file).strip
+        if head_content =~ %r{ref: refs/heads/(.+)}
+          ::Regexp.last_match(1)
+        end
+      end
+    end
+  end
+end

lib/smart_todo/todo.rb

@@ -2,12 +2,13 @@
 
 module SmartTodo
   class Todo
-    attr_reader :filepath, :comment, :indent
+    attr_reader :filepath, :comment, :indent, :line_number
     attr_reader :events, :assignees, :errors
     attr_accessor :context
 
-    def initialize(source, filepath = "-e")
+    def initialize(source, filepath = "-e", line_number = nil)
       @filepath = filepath
+      @line_number = line_number
       @comment = +""
       @indent = source[/^#(\s+)/, 1].length
 

test/smart_todo/dispatchers/output_test.rb

@@ -9,22 +9,37 @@ def setup
         @options = { fallback_channel: "#general", slack_token: "123", repo: "example" }
       end
 
-      def test_dispatch
+      def test_dispatch_with_github_link
         dispatcher = Output.new("Foo", todo_node, "file.rb", @options)
-        expected_text = <<~HEREDOC
-          Hello :wave:,
 
-          You have an assigned TODO in the `file.rb` file in repository `example`.
-          Foo
+        output = capture_io { dispatcher.dispatch }[0]
 
-          Here is the associated comment on your TODO:
+        # Verify it includes a GitHub link (we're in the smart_todo repo)
+        assert_match(%r{<https://github.com/Shopify/smart_todo/blob/[^/]+/file\.rb#L1\|file\.rb:1>}, output)
+        assert_match(/Foo/, output)
+        assert_match(/Hello :wave:,/, output)
+      end
+
+      def test_dispatch_without_github_link
+        # Use a file path in a temporary directory without a git repo
+        Dir.mktmpdir do |tmpdir|
+          filepath = File.join(tmpdir, "file.rb")
+          dispatcher = Output.new("Foo", todo_node, filepath, @options)
+          expected_text = <<~HEREDOC
+            Hello :wave:,
+
+            You have an assigned TODO in the `#{filepath}` file on line 1 in repository `example`.
+            Foo
+
+            Here is the associated comment on your TODO:
 
-          ```
+            ```
 
-          ```
-        HEREDOC
+            ```
+          HEREDOC
 
-        assert_output(expected_text) { dispatcher.dispatch }
+          assert_output(expected_text) { dispatcher.dispatch }
+        end
       end
 
       private