Refactor to Editor module and call pattern

RobinDaugherty · RobinDaugherty · commit cb2a5c50f7e4 · 2020-10-31T11:26:31.000-04:00
Adding support for BETTER_ERRORS_EDITOR env var.
diff --git a/lib/better_errors.rb b/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 +105,17 @@ 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.respond_to? :url
+      @editor = editor
+    elsif 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 +132,8 @@ 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
diff --git a/lib/better_errors/editor.rb b/lib/better_errors/editor.rb
@@ -0,0 +1,81 @@
+require "uri"
+
+module BetterErrors
+  module 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}" },
+    ]
+
+    class UsingFormattingString
+      def initialize(url_formatting_string)
+        @url_formatting_string = url_formatting_string
+      end
+
+      def url(file, line)
+        url_formatting_string % { file: URI.encode_www_form_component(file), file_unencoded: file, line: line }
+      end
+
+      private
+
+      attr_reader :url_formatting_string
+    end
+
+    class UsingProc
+      def initialize(url_proc)
+        @url_proc = url_proc
+      end
+
+      def url(file, line)
+        url_proc.call(file, line)
+      end
+
+      private
+
+      attr_reader :url_proc
+    end
+
+    def self.for_formatting_string(formatting_string)
+      UsingFormattingString.new(formatting_string)
+    end
+
+    def self.for_proc(url_proc)
+      UsingProc.new(url_proc)
+    end
+
+    def self.for_symbol(symbol)
+      KNOWN_EDITORS.each do |preset|
+        return for_formatting_string(preset[:url]) if preset[:symbols].include?(symbol)
+      end
+    end
+
+    # Automatically sniffs a default editor preset based on the EDITOR
+    # environment variable.
+    #
+    # @return [Symbol]
+    def self.default_editor
+      editor_command = ENV["EDITOR"] || ENV["BETTER_ERRORS_EDITOR"]
+      if editor_command
+        editor = editor_from_command(editor_command)
+        return editor if editor
+
+        puts "Since EDITOR or BETTER_ERRORS_EDITOR environment variable are not recognized, using Textmate by default."
+      else
+        puts "Since there is no EDITOR or BETTER_ERRORS_EDITOR environment variable, using Textmate by default."
+      end
+      for_symbol(:textmate)
+    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
+  end
+end
diff --git a/lib/better_errors/error_page.rb b/lib/better_errors/error_page.rb
@@ -90,7 +90,7 @@ 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
diff --git a/spec/better_errors_spec.rb b/spec/better_errors_spec.rb
@@ -3,77 +3,77 @@
 describe BetterErrors do
   context ".editor" do
     it "defaults to textmate" do
-      expect(subject.editor["foo.rb", 123]).to eq("txmt://open?url=file://foo.rb&line=123")
+      expect(subject.editor.url("foo.rb", 123)).to eq("txmt://open?url=file://foo.rb&line=123")
     end
 
     it "url escapes the filename" do
-      expect(subject.editor["&.rb", 0]).to eq("txmt://open?url=file://%26.rb&line=0")
+      expect(subject.editor.url("&.rb", 0)).to eq("txmt://open?url=file://%26.rb&line=0")
     end
 
     [:emacs, :emacsclient].each do |editor|
       it "uses emacs:// scheme when set to #{editor.inspect}" do
         subject.editor = editor
-        expect(subject.editor[]).to start_with "emacs://"
+        expect(subject.editor.url("file", 42)).to start_with "emacs://"
       end
     end
 
     [:macvim, :mvim].each do |editor|
       it "uses mvim:// scheme when set to #{editor.inspect}" do
         subject.editor = editor
-        expect(subject.editor[]).to start_with "mvim://"
+        expect(subject.editor.url("file", 42)).to start_with "mvim://"
       end
     end
 
     [:sublime, :subl, :st].each do |editor|
       it "uses subl:// scheme when set to #{editor.inspect}" do
         subject.editor = editor
-        expect(subject.editor[]).to start_with "subl://"
+        expect(subject.editor.url("file", 42)).to start_with "subl://"
       end
     end
 
     [:textmate, :txmt, :tm].each do |editor|
       it "uses txmt:// scheme when set to #{editor.inspect}" do
         subject.editor = editor
-        expect(subject.editor[]).to start_with "txmt://"
+        expect(subject.editor.url("file", 42)).to start_with "txmt://"
       end
     end
 
     [:atom].each do |editor|
       it "uses atom:// scheme when set to #{editor.inspect}" do
         subject.editor = editor
-        expect(subject.editor[]).to start_with "atom://"
+        expect(subject.editor.url("file", 42)).to start_with "atom://"
       end
     end
 
     ["emacsclient", "/usr/local/bin/emacsclient"].each do |editor|
       it "uses emacs:// scheme when EDITOR=#{editor}" do
         ENV["EDITOR"] = editor
         subject.editor = subject.default_editor
-        expect(subject.editor[]).to start_with "emacs://"
+        expect(subject.editor.url("file", 42)).to start_with "emacs://"
       end
     end
 
     ["mvim -f", "/usr/local/bin/mvim -f"].each do |editor|
       it "uses mvim:// scheme when EDITOR=#{editor}" do
         ENV["EDITOR"] = editor
         subject.editor = subject.default_editor
-        expect(subject.editor[]).to start_with "mvim://"
+        expect(subject.editor.url("file", 42)).to start_with "mvim://"
       end
     end
 
     ["subl -w", "/Applications/Sublime Text 2.app/Contents/SharedSupport/bin/subl"].each do |editor|
       it "uses subl:// scheme when EDITOR=#{editor}" do
         ENV["EDITOR"] = editor
         subject.editor = subject.default_editor
-        expect(subject.editor[]).to start_with "subl://"
+        expect(subject.editor.url("file", 42)).to start_with "subl://"
       end
     end
 
     ["mate -w", "/usr/bin/mate -w"].each do |editor|
       it "uses txmt:// scheme when EDITOR=#{editor}" do
         ENV["EDITOR"] = editor
         subject.editor = subject.default_editor
-        expect(subject.editor[]).to start_with "txmt://"
+        expect(subject.editor.url("file", 42)).to start_with "txmt://"
       end
     end
 
@@ -82,31 +82,31 @@
       it "uses atom:// scheme when EDITOR=#{editor}" do
         ENV["EDITOR"] = editor
         subject.editor = subject.default_editor
-        expect(subject.editor[]).to start_with "atom://"
+        expect(subject.editor.url("file", 42)).to start_with "atom://"
       end
     end
 
     ["mine"].each do |editor|
       it "uses x-mine:// scheme when EDITOR=#{editor}" do
         ENV["EDITOR"] = editor
         subject.editor = subject.default_editor
-        expect(subject.editor[]).to start_with "x-mine://"
+        expect(subject.editor.url("file", 42)).to start_with "x-mine://"
       end
     end
 
     ["idea"].each do |editor|
       it "uses idea:// scheme when EDITOR=#{editor}" do
         ENV["EDITOR"] = editor
         subject.editor = subject.default_editor
-        expect(subject.editor[]).to start_with "idea://"
+        expect(subject.editor.url("file", 42)).to start_with "idea://"
       end
     end
 
     ["vscode", "code"].each do |editor|
       it "uses vscode:// scheme when EDITOR=#{editor}" do
         ENV["EDITOR"] = editor
         subject.editor = subject.default_editor
-        expect(subject.editor[]).to start_with "vscode://"
+        expect(subject.editor.url("file", 42)).to start_with "vscode://"
       end
     end
   end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
@@ -1,6 +1,7 @@
 $: << File.expand_path("../../lib", __FILE__)
 
 ENV["EDITOR"] = nil
+ENV["BETTER_ERRORS"] = nil
 
 # Ruby 2.4.0 and 2.4.1 has a bug with its Coverage module that causes segfaults.
 # https://bugs.ruby-lang.org/issues/13305
