Rely on well-known /usr/bin/env to find Ruby

This is pretty darn normalized on *nix systems these days, where this
will be installed via Homebrew. Let's rely on that rather than
hard-coding to a version of Ruby that can/will likely change over time.

Also, use the Regex#match? and avoid extra object; we don't need/use the
MatchData, so don't create it.

Author: stevenharman

lib/git_tracker/standalone.rb

@@ -10,52 +10,32 @@ module Standalone
       # Original source files with comments are at:
       # https://github.com/stevenharman/git_tracker
       #
-
     DOC
 
-    def save(filename, path = ".")
-      dest = File.join(File.expand_path(path), filename)
-      File.open(dest, "w") do |f|
-        build(f)
-        f.chmod(0o755)
-      end
-    end
-
     def build(io)
-      io.puts "#!#{ruby_executable}"
-      io << PREAMBLE
+      io.puts("#!/usr/bin/env ruby")
+      io.puts(PREAMBLE)
 
       each_source_file do |filename|
         File.open(filename, "r") do |source|
           inline_source(source, io)
         end
       end
 
-      io.puts "GitTracker::Runner.execute(*ARGV)"
+      io.puts("GitTracker::Runner.execute(*ARGV)")
       io
     end
 
-    def ruby_executable
-      if File.executable? "/usr/bin/ruby" then "/usr/bin/ruby"
-      else
-        require "rbconfig"
-        File.join(RbConfig::CONFIG["bindir"], RbConfig::CONFIG["ruby_install_name"])
+    def save(filename, path = ".")
+      dest = File.join(File.expand_path(path), filename)
+      File.open(dest, "w") do |f|
+        build(f)
+        f.chmod(0o755)
       end
     end
 
     private
 
-    def inline_source(code, io)
-      code.each_line do |line|
-        io << line unless require_own_file?(line)
-      end
-      io.puts ""
-    end
-
-    def require_own_file?(line)
-      line =~ /^\s*require\s+["']git_tracker\//
-    end
-
     def each_source_file
       File.open(File.join(GIT_TRACKER_ROOT, "lib/git_tracker.rb"), "r") do |main|
         main.each_line do |req|
@@ -65,5 +45,16 @@ def each_source_file
         end
       end
     end
+
+    def inline_source(code, io)
+      code.each_line do |line|
+        io << line unless require_own_file?(line)
+      end
+      io.puts("")
+    end
+
+    def require_own_file?(line)
+      /^\s*require\s+["']git_tracker\//.match?(line)
+    end
   end
 end

spec/git_tracker/standalone_spec.rb

@@ -63,23 +63,4 @@
       expect(standalone_script).to_not match(/^require\s+["']git_tracker/)
     end
   end
-
-  describe "#ruby_executable" do
-    subject(:standalone) { described_class }
-
-    before do
-      allow(RbConfig::CONFIG).to receive(:[]).with("bindir") { "/some/other/bin" }
-      allow(RbConfig::CONFIG).to receive(:[]).with("ruby_install_name") { "ruby" }
-    end
-
-    it "uses user-level ruby binary when it is executable" do
-      allow(File).to receive(:executable?).with("/usr/bin/ruby") { true }
-      expect(standalone.ruby_executable).to eq("/usr/bin/ruby")
-    end
-
-    it "uses rbconfig ruby when user-level ruby binary not executable" do
-      allow(File).to receive(:executable?).with("/usr/bin/ruby") { false }
-      expect(standalone.ruby_executable).to eq("/some/other/bin/ruby")
-    end
-  end
 end