From dab1cd6ddb48d06b9e6995038769f497b9d99fa8 Mon Sep 17 00:00:00 2001
From: schneems <richard.schneeman+foo@gmail.com>
Date: Wed, 3 Nov 2021 20:01:06 -0500
Subject: [PATCH] Fix CLI edge case around position of arguments

The DeadEnd vscode extension relies on calling `dead_end --terminal <filename>` which was previously possible because calling `OptionParser#parse` mutates ARGV. The filename should be the first argument, but only after parsing, not before.
---
 CHANGELOG.md          |  2 ++
 lib/dead_end/cli.rb   | 21 ++++++++++++-----
 spec/unit/cli_spec.rb | 52 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 70 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8cf836d..3d6e75c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 ## HEAD (unreleased)
 
+- Fix CLI parsing when flags come before filename (https://github.com/zombocom/dead_end/pull/102)
+
 ## 3.0.0
 
 - [Breaking] Remove previously deprecated `require "dead_end/fyi"` interface (https://github.com/zombocom/dead_end/pull/94)
diff --git a/lib/dead_end/cli.rb b/lib/dead_end/cli.rb
index a81d9a3..6ea3aba 100644
--- a/lib/dead_end/cli.rb
+++ b/lib/dead_end/cli.rb
@@ -12,7 +12,7 @@ module DeadEnd
   #   Cli.new(argv: ["<path/to/file>.rb", "--terminal"]).call
   #
   class Cli
-    attr_accessor :options, :file_name
+    attr_accessor :options
 
     # ARGV is Everything passed to the executable, does not include executable name
     #
@@ -26,22 +26,33 @@ def initialize(argv:, exit_obj: Kernel, io: $stdout, env: ENV)
 
       @io = io
       @argv = argv
-      @file_name = argv[0]
       @exit_obj = exit_obj
     end
 
     def call
-      if file_name.nil? || file_name.empty?
+      if @argv.empty?
         # Display help if raw command
         parser.parse! %w[--help]
+        return
       else
+        # Mutates @argv
         parse
+        return if options[:exit]
       end
 
-      # Needed for testing since we fake exit
-      return if options[:exit]
+      file_name = @argv.first
+      if file_name.nil?
+        @io.puts "No file given"
+        @exit_obj.exit(1)
+        return
+      end
 
       file = Pathname(file_name)
+      if !file.exist?
+        @io.puts "file not found: #{file.expand_path} "
+        @exit_obj.exit(1)
+        return
+      end
 
       @io.puts "Record dir: #{options[:record_dir]}" if options[:record_dir]
 
diff --git a/spec/unit/cli_spec.rb b/spec/unit/cli_spec.rb
index 79a3340..8925eb4 100644
--- a/spec/unit/cli_spec.rb
+++ b/spec/unit/cli_spec.rb
@@ -61,6 +61,58 @@ def called?
       expect(out.strip).to include("❯ 36      def filename")
     end
 
+    it "parses valid code with flags" do
+      Dir.mktmpdir do |dir|
+        dir = Pathname(dir)
+        file = dir.join("script.rb")
+        file.write("puts 'lol'")
+
+        io = StringIO.new
+        exit_obj = FakeExit.new
+        cli = Cli.new(
+          io: io,
+          argv: ["--terminal", file.to_s],
+          exit_obj: exit_obj
+        )
+        cli.call
+
+        expect(exit_obj.called?).to be_truthy
+        expect(exit_obj.value).to eq(0)
+        expect(cli.options[:terminal]).to be_truthy
+        expect(io.string.strip).to eq("Syntax OK")
+      end
+    end
+
+    it "errors when no file given" do
+      io = StringIO.new
+      exit_obj = FakeExit.new
+      cli = Cli.new(
+        io: io,
+        argv: ["--terminal"],
+        exit_obj: exit_obj
+      )
+      cli.call
+
+      expect(exit_obj.called?).to be_truthy
+      expect(exit_obj.value).to eq(1)
+      expect(io.string.strip).to eq("No file given")
+    end
+
+    it "errors when file does not exist" do
+      io = StringIO.new
+      exit_obj = FakeExit.new
+      cli = Cli.new(
+        io: io,
+        argv: ["lol-i-d-o-not-ex-ist-yololo.txtblerglol"],
+        exit_obj: exit_obj
+      )
+      cli.call
+
+      expect(exit_obj.called?).to be_truthy
+      expect(exit_obj.value).to eq(1)
+      expect(io.string.strip).to include("file not found:")
+    end
+
     # We cannot execute the parser here
     # because it calls `exit` and it will exit
     # our tests, however we can assert that the