From 4f95f3bd8abdb8fd3cce346f26da3d2fcdc74030 Mon Sep 17 00:00:00 2001
From: Robin Daugherty <robin@robindaugherty.net>
Date: Sat, 31 Oct 2020 11:21:30 -0400
Subject: [PATCH 1/8] Refactor to Editor module and call pattern

Adding support for BETTER_ERRORS_EDITOR env var.
---
 lib/better_errors.rb            | 49 +++++++-------------
 lib/better_errors/editor.rb     | 81 +++++++++++++++++++++++++++++++++
 lib/better_errors/error_page.rb |  2 +-
 spec/better_errors_spec.rb      | 30 ++++++------
 spec/spec_helper.rb             |  1 +
 5 files changed, 114 insertions(+), 49 deletions(-)
 create mode 100644 lib/better_errors/editor.rb

diff --git a/lib/better_errors.rb b/lib/better_errors.rb
index 8cd6b7ec..169c1171 100644
--- 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
new file mode 100644
index 00000000..c6022322
--- /dev/null
+++ 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
index 0eb1081d..1e44bd6e 100644
--- a/lib/better_errors/error_page.rb
+++ b/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
diff --git a/spec/better_errors_spec.rb b/spec/better_errors_spec.rb
index 9d796105..2ab2a486 100644
--- a/spec/better_errors_spec.rb
+++ b/spec/better_errors_spec.rb
@@ -3,45 +3,45 @@
 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
 
@@ -49,7 +49,7 @@
       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
 
@@ -57,7 +57,7 @@
       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
 
@@ -65,7 +65,7 @@
       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
 
@@ -73,7 +73,7 @@
       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
 
@@ -82,7 +82,7 @@
       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
 
@@ -90,7 +90,7 @@
       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
 
@@ -98,7 +98,7 @@
       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
 
@@ -106,7 +106,7 @@
       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
index 9828c3f3..31d351ab 100644
--- 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
 
 require 'simplecov'
 require 'simplecov-lcov'

From c907709a723791f3d5fc129666d51c406afde4dc Mon Sep 17 00:00:00 2001
From: Robin Daugherty <robin@robindaugherty.net>
Date: Wed, 4 Nov 2020 14:14:14 -0500
Subject: [PATCH 2/8] Support for BETTER_ERRORS_EDITOR_URL

---
 lib/better_errors/editor.rb | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/lib/better_errors/editor.rb b/lib/better_errors/editor.rb
index c6022322..30ce6050 100644
--- a/lib/better_errors/editor.rb
+++ b/lib/better_errors/editor.rb
@@ -61,6 +61,12 @@ def self.for_symbol(symbol)
     #
     # @return [Symbol]
     def self.default_editor
+      editor_from_environment_formatting_string ||
+        editor_from_environment_editor ||
+        for_symbol(:textmate)
+    end
+
+    def self.editor_from_environment_editor
       editor_command = ENV["EDITOR"] || ENV["BETTER_ERRORS_EDITOR"]
       if editor_command
         editor = editor_from_command(editor_command)
@@ -70,12 +76,17 @@ def self.default_editor
       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
+
+    def self.editor_from_environment_formatting_string
+      return unless ENV['BETTER_ERRORS_EDITOR_URL']
+
+      for_formatting_string(ENV['BETTER_ERRORS_EDITOR_URL'])
+    end
   end
 end

From 2b520a0fa5564b69a28c7415a7deacd50553c2d3 Mon Sep 17 00:00:00 2001
From: Robin Daugherty <robin@robindaugherty.net>
Date: Wed, 4 Nov 2020 15:10:01 -0500
Subject: [PATCH 3/8] Remove new undocumented behavior

of passing an object that responds to #url.
---
 lib/better_errors.rb | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/lib/better_errors.rb b/lib/better_errors.rb
index 169c1171..af46bdd5 100644
--- a/lib/better_errors.rb
+++ b/lib/better_errors.rb
@@ -105,9 +105,7 @@ def self.editor
   #   @param [Proc] proc
   #
   def self.editor=(editor)
-    if editor.respond_to? :url
-      @editor = editor
-    elsif editor.is_a? Symbol
+    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

From 5931137088b0d688745462ca1a9c1553233ef4c6 Mon Sep 17 00:00:00 2001
From: Robin Daugherty <robin@robindaugherty.net>
Date: Wed, 4 Nov 2020 15:10:32 -0500
Subject: [PATCH 4/8] Specs for Editor module

---
 lib/better_errors/editor.rb       |  17 ++-
 spec/better_errors/editor_spec.rb | 233 ++++++++++++++++++++++++++++++
 spec/better_errors_spec.rb        | 129 +++++------------
 3 files changed, 276 insertions(+), 103 deletions(-)
 create mode 100644 spec/better_errors/editor_spec.rb

diff --git a/lib/better_errors/editor.rb b/lib/better_errors/editor.rb
index 30ce6050..0e998637 100644
--- a/lib/better_errors/editor.rb
+++ b/lib/better_errors/editor.rb
@@ -56,8 +56,8 @@ def self.for_symbol(symbol)
       end
     end
 
-    # Automatically sniffs a default editor preset based on the EDITOR
-    # environment variable.
+    # Automatically sniffs a default editor preset based on
+    # environment variables.
     #
     # @return [Symbol]
     def self.default_editor
@@ -67,12 +67,15 @@ def self.default_editor
     end
 
     def self.editor_from_environment_editor
-      editor_command = ENV["EDITOR"] || ENV["BETTER_ERRORS_EDITOR"]
-      if editor_command
-        editor = editor_from_command(editor_command)
+      if ENV["BETTER_ERRORS_EDITOR"]
+        editor = editor_from_command(ENV["BETTER_ERRORS_EDITOR"])
         return editor if editor
-
-        puts "Since EDITOR or BETTER_ERRORS_EDITOR environment variable are not recognized, using Textmate by default."
+        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
diff --git a/spec/better_errors/editor_spec.rb b/spec/better_errors/editor_spec.rb
new file mode 100644
index 00000000..efc73608
--- /dev/null
+++ b/spec/better_errors/editor_spec.rb
@@ -0,0 +1,233 @@
+require "spec_helper"
+
+RSpec.describe BetterErrors::Editor do
+  describe ".for_formatting_string" do
+    it "returns an object that reponds to #url" do
+      editor = described_class.for_formatting_string("custom://%{file}:%{file_unencoded}:%{line}")
+      expect(editor.url("/path&file", 42)).to eq("custom://%2Fpath%26file:/path&file:42")
+    end
+  end
+
+  describe ".for_proc" do
+    it "returns an object that responds to #url, which calls the proc" do
+      editor = described_class.for_proc(proc { |file, line| "result" } )
+      expect(editor.url("foo", 42)).to eq("result")
+    end
+  end
+
+  describe ".for_symbol" do
+    subject { described_class.for_symbol(symbol) }
+
+    [:atom].each do |symbol|
+      context "when symbol is '#{symbol}'" do
+        let(:symbol) { symbol }
+
+        it "uses atom:// scheme" do
+          expect(subject.url("file", 42)).to start_with("atom://")
+        end
+      end
+    end
+
+    [:emacs, :emacsclient].each do |symbol|
+      context "when symbol is '#{symbol}'" do
+        let(:symbol) { symbol }
+        it "uses emacs:// scheme" do
+          expect(subject.url("file", 42)).to start_with("emacs://")
+        end
+      end
+    end
+
+    [:macvim, :mvim].each do |symbol|
+      context "when symbol is '#{symbol}'" do
+        let(:symbol) { symbol }
+
+        it "uses mvim:// scheme" do
+          expect(subject.url("file", 42)).to start_with("mvim://")
+        end
+      end
+    end
+
+    [:sublime, :subl, :st].each do |symbol|
+      context "when symbol is '#{symbol}'" do
+        let(:symbol) { symbol }
+
+        it "uses subl:// scheme" do
+          expect(subject.url("file", 42)).to start_with("subl://")
+        end
+      end
+    end
+
+    [:textmate, :txmt, :tm].each do |symbol|
+      context "when symbol is '#{symbol}'" do
+        let(:symbol) { symbol }
+
+        it "uses txmt:// scheme" do
+          expect(subject.url("file", 42)).to start_with("txmt://")
+        end
+      end
+    end
+  end
+
+  describe ".default_editor" do
+    subject(:default_editor) { described_class.default_editor }
+    before do
+      ENV['BETTER_ERRORS_EDITOR_URL'] = nil
+      ENV['BETTER_ERRORS_EDITOR'] = nil
+      ENV['EDITOR'] = nil
+    end
+
+    it "returns an object that responds to #url" do
+        expect(default_editor.url("foo", 123)).to match(/foo/)
+    end
+
+    context "when $BETTER_ERRORS_EDITOR_URL is set" do
+      before do
+        ENV['BETTER_ERRORS_EDITOR_URL'] = "custom://%{file}:%{file_unencoded}:%{line}"
+      end
+
+      it "uses the value as a formatting string to build the editor URL" do
+        expect(default_editor.url("/path&file", 42)).to eq("custom://%2Fpath%26file:/path&file:42")
+      end
+    end
+
+    context "when $BETTER_ERRORS_EDITOR is set to one of the preset commands" do
+      before do
+        ENV['BETTER_ERRORS_EDITOR'] = "subl"
+      end
+
+      it "returns an object that builds URLs for the corresponding editor" do
+        expect(default_editor.url("foo", 123)).to start_with('subl://')
+      end
+    end
+
+    context "when $EDITOR is set to one of the preset commands" do
+      before do
+        ENV['EDITOR'] = "subl"
+      end
+
+      it "returns an object that builds URLs for the corresponding editor" do
+        expect(default_editor.url("foo", 123)).to start_with('subl://')
+      end
+
+      context "when $BETTER_ERRORS_EDITOR is set to one of the preset commands" do
+        before do
+          ENV['BETTER_ERRORS_EDITOR'] = "emacs"
+        end
+
+        it "returns an object that builds URLs for that editor instead" do
+          expect(default_editor.url("foo", 123)).to start_with('emacs://')
+        end
+      end
+
+      context "when $BETTER_ERRORS_EDITOR is set to an unrecognized command" do
+        before do
+          ENV['BETTER_ERRORS_EDITOR'] = "fubarcmd"
+        end
+
+        it "returns an object that builds URLs for the $EDITOR instead" do
+          expect(default_editor.url("foo", 123)).to start_with('subl://')
+        end
+      end
+    end
+
+    context "when $EDITOR is set to an unrecognized command" do
+      before do
+        ENV['EDITOR'] = "fubarcmd"
+      end
+
+      it "returns an object that builds URLs for TextMate" do
+        expect(default_editor.url("foo", 123)).to start_with('txmt://')
+      end
+    end
+
+    context "when $EDITOR and $BETTER_ERRORS_EDITOR are not set" do
+      it "returns an object that builds URLs for TextMate" do
+        expect(default_editor.url("foo", 123)).to start_with('txmt://')
+      end
+    end
+  end
+
+  describe ".editor_from_command" do
+    subject { described_class.editor_from_command(command_line) }
+
+    ["atom -w", "/usr/bin/atom -w"].each do |command|
+      context "when editor command is '#{command}'" do
+        let(:command_line) { command }
+
+        it "uses atom:// scheme" do
+          expect(subject.url("file", 42)).to start_with("atom://")
+        end
+      end
+    end
+
+    ["emacsclient", "/usr/local/bin/emacsclient"].each do |command|
+      context "when editor command is '#{command}'" do
+        let(:command_line) { command }
+
+        it "uses emacs:// scheme" do
+          expect(subject.url("file", 42)).to start_with("emacs://")
+        end
+      end
+    end
+
+    ["idea"].each do |command|
+      context "when editor command is '#{command}'" do
+        let(:command_line) { command }
+
+        it "uses idea:// scheme" do
+          expect(subject.url("file", 42)).to start_with("idea://")
+        end
+      end
+    end
+
+    ["mate -w", "/usr/bin/mate -w"].each do |command|
+      context "when editor command is '#{command}'" do
+        let(:command_line) { command }
+
+        it "uses txmt:// scheme" do
+          expect(subject.url("file", 42)).to start_with("txmt://")
+        end
+      end
+    end
+
+    ["mine"].each do |command|
+      context "when editor command is '#{command}'" do
+        let(:command_line) { command }
+
+        it "uses x-mine:// scheme" do
+          expect(subject.url("file", 42)).to start_with("x-mine://")
+        end
+      end
+    end
+
+    ["mvim -f", "/usr/local/bin/mvim -f"].each do |command|
+      context "when editor command is '#{command}'" do
+        let(:command_line) { command }
+
+        it "uses mvim:// scheme" do
+          expect(subject.url("file", 42)).to start_with("mvim://")
+        end
+      end
+    end
+
+    ["subl -w", "/Applications/Sublime Text 2.app/Contents/SharedSupport/bin/subl"].each do |command|
+      context "when editor command is '#{command}'" do
+        let(:command_line) { command }
+
+        it "uses subl:// scheme" do
+          expect(subject.url("file", 42)).to start_with("subl://")
+        end
+      end
+    end
+
+    ["vscode", "code"].each do |command|
+      context "when editor command is '#{command}'" do
+        let(:command_line) { command }
+
+        it "uses vscode:// scheme" do
+          expect(subject.url("file", 42)).to start_with("vscode://")
+        end
+      end
+    end
+  end
+end
diff --git a/spec/better_errors_spec.rb b/spec/better_errors_spec.rb
index 2ab2a486..0b5b6604 100644
--- a/spec/better_errors_spec.rb
+++ b/spec/better_errors_spec.rb
@@ -1,112 +1,49 @@
 require "spec_helper"
 
-describe BetterErrors do
-  context ".editor" do
-    it "defaults to textmate" do
-      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.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.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.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.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.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.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.url("file", 42)).to start_with "emacs://"
+RSpec.describe BetterErrors do
+  describe ".editor" do
+    context "when set to a specific value" do
+      before do
+        allow(BetterErrors::Editor).to receive(:for_symbol).and_return(:editor_from_symbol)
+        allow(BetterErrors::Editor).to receive(:for_formatting_string).and_return(:editor_from_formatting_string)
+        allow(BetterErrors::Editor).to receive(:for_proc).and_return(:editor_from_proc)
       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.url("file", 42)).to start_with "mvim://"
+      context "when the value is a string" do
+        it "uses BetterErrors::Editor.for_formatting_string to set the value" do
+          subject.editor = "thing://%{file}"
+          expect(BetterErrors::Editor).to have_received(:for_formatting_string).with("thing://%{file}")
+          expect(subject.editor).to eq(:editor_from_formatting_string)
+        end
       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.url("file", 42)).to start_with "subl://"
+      context "when the value is a Proc" do
+        it "uses BetterErrors::Editor.for_proc to set the value" do
+          my_proc = proc { "thing" }
+          subject.editor = my_proc
+          expect(BetterErrors::Editor).to have_received(:for_proc).with(my_proc)
+          expect(subject.editor).to eq(:editor_from_proc)
+        end
       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.url("file", 42)).to start_with "txmt://"
+      context "when the value is a symbol" do
+        it "uses BetterErrors::Editor.for_symbol to set the value" do
+          subject.editor = :subl
+          expect(BetterErrors::Editor).to have_received(:for_symbol).with(:subl)
+          expect(subject.editor).to eq(:editor_from_symbol)
+        end
       end
     end
 
-
-    ["atom -w", "/usr/bin/atom -w"].each do |editor|
-      it "uses atom:// scheme when EDITOR=#{editor}" do
-        ENV["EDITOR"] = editor
-        subject.editor = subject.default_editor
-        expect(subject.editor.url("file", 42)).to start_with "atom://"
+    context "when no value has been set" do
+      before do
+        BetterErrors.instance_variable_set('@editor', nil)
+        allow(BetterErrors::Editor).to receive(:default_editor).and_return(:default_editor)
       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.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.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.url("file", 42)).to start_with "vscode://"
+      it "uses BetterErrors::Editor.default_editor to set the default value" do
+          expect(subject.editor).to eq(:default_editor)
+          expect(BetterErrors::Editor).to have_received(:default_editor)
       end
     end
   end

From b95d3c334d749a94f162fba1b68c0b9e0f68aa4f Mon Sep 17 00:00:00 2001
From: Robin Daugherty <robin@robindaugherty.net>
Date: Wed, 4 Nov 2020 15:14:38 -0500
Subject: [PATCH 5/8] Create instances of Editor

---
 lib/better_errors/editor.rb | 48 +++++++++++++------------------------
 1 file changed, 17 insertions(+), 31 deletions(-)

diff --git a/lib/better_errors/editor.rb b/lib/better_errors/editor.rb
index 0e998637..cc8bf383 100644
--- a/lib/better_errors/editor.rb
+++ b/lib/better_errors/editor.rb
@@ -1,7 +1,7 @@
 require "uri"
 
 module BetterErrors
-  module Editor
+  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}" },
@@ -14,40 +14,14 @@ module Editor
       { 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)
+      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)
-      UsingProc.new(url_proc)
+      new url_proc
     end
 
     def self.for_symbol(symbol)
@@ -91,5 +65,17 @@ def self.editor_from_environment_formatting_string
 
       for_formatting_string(ENV['BETTER_ERRORS_EDITOR_URL'])
     end
+
+    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
 end

From 6591cf998872940ae64086444aa59be30f1cbe9c Mon Sep 17 00:00:00 2001
From: Robin Daugherty <robin@robindaugherty.net>
Date: Wed, 4 Nov 2020 15:16:47 -0500
Subject: [PATCH 6/8] Rename method and reorder

---
 lib/better_errors/editor.rb       |  14 ++--
 spec/better_errors/editor_spec.rb | 106 +++++++++++++++---------------
 2 files changed, 60 insertions(+), 60 deletions(-)

diff --git a/lib/better_errors/editor.rb b/lib/better_errors/editor.rb
index cc8bf383..06df7f4d 100644
--- a/lib/better_errors/editor.rb
+++ b/lib/better_errors/editor.rb
@@ -24,12 +24,6 @@ def self.for_proc(url_proc)
       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
     # environment variables.
     #
@@ -37,7 +31,7 @@ def self.for_symbol(symbol)
     def self.default_editor
       editor_from_environment_formatting_string ||
         editor_from_environment_editor ||
-        for_symbol(:textmate)
+        editor_from_symbol(:textmate)
     end
 
     def self.editor_from_environment_editor
@@ -66,6 +60,12 @@ def self.editor_from_environment_formatting_string
       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
diff --git a/spec/better_errors/editor_spec.rb b/spec/better_errors/editor_spec.rb
index efc73608..033c05d5 100644
--- a/spec/better_errors/editor_spec.rb
+++ b/spec/better_errors/editor_spec.rb
@@ -15,59 +15,6 @@
     end
   end
 
-  describe ".for_symbol" do
-    subject { described_class.for_symbol(symbol) }
-
-    [:atom].each do |symbol|
-      context "when symbol is '#{symbol}'" do
-        let(:symbol) { symbol }
-
-        it "uses atom:// scheme" do
-          expect(subject.url("file", 42)).to start_with("atom://")
-        end
-      end
-    end
-
-    [:emacs, :emacsclient].each do |symbol|
-      context "when symbol is '#{symbol}'" do
-        let(:symbol) { symbol }
-        it "uses emacs:// scheme" do
-          expect(subject.url("file", 42)).to start_with("emacs://")
-        end
-      end
-    end
-
-    [:macvim, :mvim].each do |symbol|
-      context "when symbol is '#{symbol}'" do
-        let(:symbol) { symbol }
-
-        it "uses mvim:// scheme" do
-          expect(subject.url("file", 42)).to start_with("mvim://")
-        end
-      end
-    end
-
-    [:sublime, :subl, :st].each do |symbol|
-      context "when symbol is '#{symbol}'" do
-        let(:symbol) { symbol }
-
-        it "uses subl:// scheme" do
-          expect(subject.url("file", 42)).to start_with("subl://")
-        end
-      end
-    end
-
-    [:textmate, :txmt, :tm].each do |symbol|
-      context "when symbol is '#{symbol}'" do
-        let(:symbol) { symbol }
-
-        it "uses txmt:// scheme" do
-          expect(subject.url("file", 42)).to start_with("txmt://")
-        end
-      end
-    end
-  end
-
   describe ".default_editor" do
     subject(:default_editor) { described_class.default_editor }
     before do
@@ -230,4 +177,57 @@
       end
     end
   end
+
+  describe ".editor_from_symbol" do
+    subject { described_class.editor_from_symbol(symbol) }
+
+    [:atom].each do |symbol|
+      context "when symbol is '#{symbol}'" do
+        let(:symbol) { symbol }
+
+        it "uses atom:// scheme" do
+          expect(subject.url("file", 42)).to start_with("atom://")
+        end
+      end
+    end
+
+    [:emacs, :emacsclient].each do |symbol|
+      context "when symbol is '#{symbol}'" do
+        let(:symbol) { symbol }
+        it "uses emacs:// scheme" do
+          expect(subject.url("file", 42)).to start_with("emacs://")
+        end
+      end
+    end
+
+    [:macvim, :mvim].each do |symbol|
+      context "when symbol is '#{symbol}'" do
+        let(:symbol) { symbol }
+
+        it "uses mvim:// scheme" do
+          expect(subject.url("file", 42)).to start_with("mvim://")
+        end
+      end
+    end
+
+    [:sublime, :subl, :st].each do |symbol|
+      context "when symbol is '#{symbol}'" do
+        let(:symbol) { symbol }
+
+        it "uses subl:// scheme" do
+          expect(subject.url("file", 42)).to start_with("subl://")
+        end
+      end
+    end
+
+    [:textmate, :txmt, :tm].each do |symbol|
+      context "when symbol is '#{symbol}'" do
+        let(:symbol) { symbol }
+
+        it "uses txmt:// scheme" do
+          expect(subject.url("file", 42)).to start_with("txmt://")
+        end
+      end
+    end
+  end
 end

From 45915e6a1c5e777f5fb975ef3094642a75fb6b66 Mon Sep 17 00:00:00 2001
From: Robin Daugherty <robin@robindaugherty.net>
Date: Wed, 4 Nov 2020 15:31:28 -0500
Subject: [PATCH 7/8] Support for virtual and host paths

---
 lib/better_errors/editor.rb       | 20 ++++++++++++++++-
 spec/better_errors/editor_spec.rb | 37 +++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/lib/better_errors/editor.rb b/lib/better_errors/editor.rb
index 06df7f4d..b8de8fb7 100644
--- a/lib/better_errors/editor.rb
+++ b/lib/better_errors/editor.rb
@@ -70,12 +70,30 @@ def initialize(url_proc)
       @url_proc = url_proc
     end
 
-    def url(file, line)
+    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
diff --git a/spec/better_errors/editor_spec.rb b/spec/better_errors/editor_spec.rb
index 033c05d5..ca0127a3 100644
--- a/spec/better_errors/editor_spec.rb
+++ b/spec/better_errors/editor_spec.rb
@@ -230,4 +230,41 @@
       end
     end
   end
+
+  describe "#url" do
+    subject(:url) { described_instance.url("/full/path/to/lib/file.rb", 42) }
+    let(:described_instance) { described_class.for_formatting_string("%{file_unencoded}")}
+    before do
+      ENV['BETTER_ERRORS_VIRTUAL_PATH'] = virtual_path
+      ENV['BETTER_ERRORS_HOST_PATH'] = host_path
+    end
+    let(:virtual_path) { nil }
+    let(:host_path) { nil }
+
+    context "when $BETTER_ERRORS_VIRTUAL_PATH is set" do
+      let(:virtual_path) { "/full/path/to" }
+
+      context "when $BETTER_ERRORS_HOST_PATH is not set" do
+        let(:host_path) { nil }
+
+        it "removes the VIRTUAL_PATH prefix, making the path relative" do
+          expect(url).to eq("lib/file.rb")
+        end  
+      end
+
+      context "when $BETTER_ERRORS_HOST_PATH is set" do
+        let(:host_path) { '/Users/myname/Code' }
+
+        it "replaces the VIRTUAL_PATH prefix with the HOST_PATH" do
+          expect(url).to eq("/Users/myname/Code/lib/file.rb")
+        end  
+      end
+    end
+
+    context "when $BETTER_ERRORS_VIRTUAL_PATH is not set" do
+      it "does not alter file paths" do
+        expect(url).to eq("/full/path/to/lib/file.rb")
+      end
+    end
+  end
 end

From 123f9b327e8dc9c960c87dfaf876a8d519be57a4 Mon Sep 17 00:00:00 2001
From: Robin Daugherty <robin@robindaugherty.net>
Date: Wed, 4 Nov 2020 15:33:22 -0500
Subject: [PATCH 8/8] Test invalid editor

---
 spec/better_errors_spec.rb | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/spec/better_errors_spec.rb b/spec/better_errors_spec.rb
index 0b5b6604..fbec6e7c 100644
--- a/spec/better_errors_spec.rb
+++ b/spec/better_errors_spec.rb
@@ -33,6 +33,12 @@
           expect(subject.editor).to eq(:editor_from_symbol)
         end
       end
+
+      context "when set to something else" do
+        it "raises an ArgumentError" do
+          expect { subject.editor = Class.new }.to raise_error(ArgumentError)
+        end
+      end
     end
 
     context "when no value has been set" do