From 0d426473f379523cf28faf4bafe25c453f84875f Mon Sep 17 00:00:00 2001
From: Simon <simon.toivo@telhaug.no>
Date: Fri, 22 Oct 2021 15:24:46 +0200
Subject: [PATCH] Use color if stdout is a tty
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

It's quite commen for commands use check if the output is a terminal or for and use that to determine if it should print colors.

When you print these codes to an none interactive shell it looks like. This could be build tools integrated in ides or Ci.
```
        4  describe Iso20022::Camt053 do
      223    describe "::Parser", :aggregate_failures do
    ❯ 376      fdescribe "DNB cryptic description" do
    ❯ 400      end
    ❯ 401      end
      535    end
      536  end
    
```
---
 CHANGELOG.md                           |  2 ++
 exe/dead_end                           |  5 ++++-
 lib/dead_end/display_invalid_blocks.rb |  4 ++--
 lib/dead_end/internals.rb              |  3 +--
 spec/integration/exe_cli_spec.rb       | 19 ++++++++++++++++---
 5 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 82d5ba3..f24aeb1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 ## HEAD (unreleased)
 
+- Don't print terminal color codes when output is not tty (https://github.com/zombocom/dead_end/pull/91)
+
 ## 2.0.1
 
 - Reintroduce Ruby 2.5 support (https://github.com/zombocom/dead_end/pull/90)
diff --git a/exe/dead_end b/exe/dead_end
index 053c180..2ea5070 100755
--- a/exe/dead_end
+++ b/exe/dead_end
@@ -5,7 +5,6 @@ require "optparse"
 require_relative "../lib/dead_end"
 
 options = {}
-options[:terminal] = true
 options[:record_dir] = ENV["DEAD_END_RECORD_DIR"]
 
 parser = OptionParser.new do |opts|
@@ -46,6 +45,10 @@ parser = OptionParser.new do |opts|
     options[:record_dir] = v
   end
 
+  opts.on("--terminal", "Enable terminal highlighting") do |v|
+    options[:terminal] = true
+  end
+
   opts.on("--no-terminal", "Disable terminal highlighting") do |v|
     options[:terminal] = false
   end
diff --git a/lib/dead_end/display_invalid_blocks.rb b/lib/dead_end/display_invalid_blocks.rb
index 9d22c72..f659473 100644
--- a/lib/dead_end/display_invalid_blocks.rb
+++ b/lib/dead_end/display_invalid_blocks.rb
@@ -9,8 +9,8 @@ module DeadEnd
   class DisplayInvalidBlocks
     attr_reader :filename
 
-    def initialize(code_lines:, blocks:, io: $stderr, filename: nil, terminal: false, invalid_obj: WhoDisSyntaxError::Null.new)
-      @terminal = terminal
+    def initialize(code_lines:, blocks:, io: $stderr, filename: nil, terminal: nil, invalid_obj: WhoDisSyntaxError::Null.new)
+      @terminal = terminal.nil? ? io.isatty : terminal
       @filename = filename
       @io = io
 
diff --git a/lib/dead_end/internals.rb b/lib/dead_end/internals.rb
index bd87c64..26008f9 100644
--- a/lib/dead_end/internals.rb
+++ b/lib/dead_end/internals.rb
@@ -28,14 +28,13 @@ def self.handle_error(e, search_source_on_error: SEARCH_SOURCE_ON_ERROR_DEFAULT)
       call(
         source: Pathname(filename).read,
         filename: filename,
-        terminal: true
       )
     end
 
     raise e
   end
 
-  def self.call(source:, filename:, terminal: false, record_dir: nil, timeout: TIMEOUT_DEFAULT, io: $stderr)
+  def self.call(source:, filename:, terminal: nil, record_dir: nil, timeout: TIMEOUT_DEFAULT, io: $stderr)
     search = nil
     Timeout.timeout(timeout) do
       record_dir ||= ENV["DEBUG"] ? "tmp" : nil
diff --git a/spec/integration/exe_cli_spec.rb b/spec/integration/exe_cli_spec.rb
index c1742c0..b3b606b 100644
--- a/spec/integration/exe_cli_spec.rb
+++ b/spec/integration/exe_cli_spec.rb
@@ -23,7 +23,7 @@ def exe(cmd)
 
     it "parses invalid code" do
       ruby_file = fixtures_dir.join("this_project_extra_def.rb.txt")
-      out = exe("#{ruby_file} --no-terminal")
+      out = exe(ruby_file)
 
       expect(out.strip).to include("Missing `end` detected")
       expect(out.strip).to include("❯ 36      def filename")
@@ -32,13 +32,13 @@ def exe(cmd)
     end
 
     it "handles heredocs" do
+      lines = fixtures_dir.join("rexe.rb.txt").read.lines
       Tempfile.create do |file|
-        lines = fixtures_dir.join("rexe.rb.txt").read.lines
         lines.delete_at(85 - 1)
 
         Pathname(file.path).write(lines.join)
 
-        out = exe("#{file.path} --no-terminal")
+        out = exe(file.path)
 
         expect(out).to include(<<~EOM.indent(4))
              16  class Rexe
@@ -50,6 +50,19 @@ def exe(cmd)
       end
     end
 
+    describe "terminal coloring" do
+      # When ruby sub shells it is not a interactive shell and dead_end will
+      # default to no coloring.
+
+      it "passing --terminal will force color codes" do
+        ruby_file = fixtures_dir.join("this_project_extra_def.rb.txt")
+        out = exe("#{ruby_file} --terminal")
+
+        expect(out.strip).to include("Missing `end` detected")
+        expect(out.strip).to include("\e[0m❯ 36  \e[1;3m    def filename")
+      end
+    end
+
     it "records search" do
       Dir.mktmpdir do |dir|
         dir = Pathname(dir)