Merge pull request #488 from BetterErrors/feature/editor-support-docker

Improve editor support for virtual environments

Author: RobinDaugherty

lib/better_errors.rb

@@ -11,20 +11,9 @@
 require "better_errors/raised_exception"
 require "better_errors/repl"
 require "better_errors/stack_frame"
+require "better_errors/editor"
 
 module BetterErrors
-  POSSIBLE_EDITOR_PRESETS = [
-    { symbols: [:emacs, :emacsclient],  sniff: /emacs/i, url: "emacs://open?url=file://%{file}&line=%{line}" },
-    { symbols: [:macvim, :mvim],        sniff: /vim/i,   url: proc { |file, line| "mvim://open?url=file://#{file}&line=#{line}" } },
-    { symbols: [:sublime, :subl, :st],  sniff: /subl/i,  url: "subl://open?url=file://%{file}&line=%{line}" },
-    { symbols: [:textmate, :txmt, :tm], sniff: /mate/i,  url: "txmt://open?url=file://%{file}&line=%{line}" },
-    { symbols: [:idea], sniff: /idea/i, url: "idea://open?file=%{file}&line=%{line}" },
-    { symbols: [:rubymine], sniff: /mine/i, url: "x-mine://open?file=%{file}&line=%{line}" },
-    { symbols: [:vscode, :code], sniff: /code/i, url: "vscode://file/%{file}:%{line}" },
-    { symbols: [:vscodium, :codium], sniff: /codium/i, url: "vscodium://file/%{file}:%{line}" },
-    { symbols: [:atom], sniff: /atom/i,  url: "atom://core/open/file?filename=%{file}&line=%{line}" },
-  ]
-
   class << self
     # The path to the root of the application. Better Errors uses this property
     # to determine if a file in a backtrace should be considered an application
@@ -64,17 +53,18 @@ class << self
   @maximum_variable_inspect_size = 100_000
   @ignored_classes = ['ActionDispatch::Request', 'ActionDispatch::Response']
 
-  # Returns a proc, which when called with a filename and line number argument,
+  # Returns an object which responds to #url, which when called with
+  # a filename and line number argument,
   # returns a URL to open the filename and line in the selected editor.
   #
   # Generates TextMate URLs by default.
   #
-  #   BetterErrors.editor["/some/file", 123]
+  #   BetterErrors.editor.url("/some/file", 123)
   #     # => txmt://open?url=file:///some/file&line=123
   #
   # @return [Proc]
   def self.editor
-    @editor
+    @editor ||= default_editor
   end
 
   # Configures how Better Errors generates open-in-editor URLs.
@@ -115,20 +105,15 @@ def self.editor
   #   @param [Proc] proc
   #
   def self.editor=(editor)
-    POSSIBLE_EDITOR_PRESETS.each do |config|
-      if config[:symbols].include?(editor)
-        return self.editor = config[:url]
-      end
-    end
-
-    if editor.is_a? String
-      self.editor = proc { |file, line| editor % { file: URI.encode_www_form_component(file), line: line } }
+    if editor.is_a? Symbol
+      @editor = Editor.for_symbol(editor)
+      raise(ArgumentError, "Symbol #{editor} is not a symbol in the list of supported errors.") unless editor
+    elsif editor.is_a? String
+      @editor = Editor.for_formatting_string(editor)
+    elsif editor.respond_to? :call
+      @editor = Editor.for_proc(editor)
     else
-      if editor.respond_to? :call
-        @editor = editor
-      else
-        raise TypeError, "Expected editor to be a valid editor key, a format string or a callable."
-      end
+      raise ArgumentError, "Expected editor to be a valid editor key, a format string or a callable."
     end
   end
 
@@ -145,12 +130,8 @@ def self.use_pry!
   #
   # @return [Symbol]
   def self.default_editor
-    POSSIBLE_EDITOR_PRESETS.detect(-> { {} }) { |config|
-      ENV["EDITOR"] =~ config[:sniff]
-    }[:url] || :textmate
+    Editor.default_editor
   end
-
-  BetterErrors.editor = default_editor
 end
 
 begin

lib/better_errors/editor.rb

@@ -0,0 +1,99 @@
+require "uri"
+
+module BetterErrors
+  class Editor
+    KNOWN_EDITORS = [
+      { symbols: [:atom], sniff: /atom/i, url: "atom://core/open/file?filename=%{file}&line=%{line}" },
+      { symbols: [:emacs, :emacsclient], sniff: /emacs/i, url: "emacs://open?url=file://%{file}&line=%{line}" },
+      { symbols: [:idea], sniff: /idea/i, url: "idea://open?file=%{file}&line=%{line}" },
+      { symbols: [:macvim, :mvim], sniff: /vim/i, url: "mvim://open?url=file://%{file_unencoded}&line=%{line}" },
+      { symbols: [:rubymine], sniff: /mine/i, url: "x-mine://open?file=%{file}&line=%{line}" },
+      { symbols: [:sublime, :subl, :st], sniff: /subl/i, url: "subl://open?url=file://%{file}&line=%{line}" },
+      { symbols: [:textmate, :txmt, :tm], sniff: /mate/i, url: "txmt://open?url=file://%{file}&line=%{line}" },
+      { symbols: [:vscode, :code], sniff: /code/i, url: "vscode://file/%{file}:%{line}" },
+      { symbols: [:vscodium, :codium], sniff: /codium/i, url: "vscodium://file/%{file}:%{line}" },
+    ]
+
+    def self.for_formatting_string(formatting_string)
+      new proc { |file, line|
+        formatting_string % { file: URI.encode_www_form_component(file), file_unencoded: file, line: line }
+      }
+    end
+
+    def self.for_proc(url_proc)
+      new url_proc
+    end
+
+    # Automatically sniffs a default editor preset based on
+    # environment variables.
+    #
+    # @return [Symbol]
+    def self.default_editor
+      editor_from_environment_formatting_string ||
+        editor_from_environment_editor ||
+        editor_from_symbol(:textmate)
+    end
+
+    def self.editor_from_environment_editor
+      if ENV["BETTER_ERRORS_EDITOR"]
+        editor = editor_from_command(ENV["BETTER_ERRORS_EDITOR"])
+        return editor if editor
+        puts "BETTER_ERRORS_EDITOR environment variable is not recognized as a supported Better Errors editor."
+      end
+      if ENV["EDITOR"]
+        editor = editor_from_command(ENV["EDITOR"])
+        return editor if editor
+        puts "EDITOR environment variable is not recognized as a supported Better Errors editor. Using TextMate by default."
+      else
+        puts "Since there is no EDITOR or BETTER_ERRORS_EDITOR environment variable, using Textmate by default."
+      end
+    end
+
+    def self.editor_from_command(editor_command)
+      env_preset = KNOWN_EDITORS.find { |preset| editor_command =~ preset[:sniff] }
+      for_formatting_string(env_preset[:url]) if env_preset
+    end
+
+    def self.editor_from_environment_formatting_string
+      return unless ENV['BETTER_ERRORS_EDITOR_URL']
+
+      for_formatting_string(ENV['BETTER_ERRORS_EDITOR_URL'])
+    end
+
+    def self.editor_from_symbol(symbol)
+      KNOWN_EDITORS.each do |preset|
+        return for_formatting_string(preset[:url]) if preset[:symbols].include?(symbol)
+      end
+    end
+
+    def initialize(url_proc)
+      @url_proc = url_proc
+    end
+
+    def url(raw_path, line)
+      if virtual_path && raw_path.start_with?(virtual_path)
+        if host_path
+          file = raw_path.sub(%r{\A#{virtual_path}}, host_path)
+        else
+          file = raw_path.sub(%r{\A#{virtual_path}/}, '')
+        end
+      else
+        file = raw_path
+      end
+        
+      url_proc.call(file, line)
+    end
+
+    private
+
+    attr_reader :url_proc
+
+    def virtual_path
+      @virtual_path ||= ENV['BETTER_ERRORS_VIRTUAL_PATH']
+    end
+
+    def host_path
+      @host_path ||= ENV['BETTER_ERRORS_HOST_PATH']
+    end
+  end
+end

lib/better_errors/error_page.rb

@@ -94,7 +94,7 @@ def first_frame
     private
 
     def editor_url(frame)
-      BetterErrors.editor[frame.filename, frame.line]
+      BetterErrors.editor.url(frame.filename, frame.line)
     end
 
     def rack_session