Default to local Gemfile

README.md

@@ -24,33 +24,27 @@ gem 'gem_dating', group: [:development], require: false
 
 ### Running GemDating
 
-This gem provides a *very* limited command line interface. It may be invoked with:
+This gem provides a small command line interface. It may be invoked with:
 
 ```bash
-$ gem_dating [path/to/Gemfile]
+$ gem_dating
 ```
 
-Given a path to a Gemfile, GemDating will output a list of gems and their relative ages to the stdout stream.
+By default, GemDating will look for a Gemfile in the current directory.
+If it finds one, it will output a list of gems and their relative ages to the stdout stream.
 
-For example(using gem exec):
-```bash
-$ gem exec gem_dating ~/code/my_app/Gemfile
-```
+You may also pass a path to a Gemfile as an argument:
 
-or (using installed gem):
 ```bash
 $ gem_dating ~/code/my_app/Gemfile
-```
-
-to see the output in your terminal.
+``` 
 
-Or you can run
+GemDating leans on `$stdout`, so you can pipe the output to a file if you'd like:
 ```bash
 $ gem_dating ~/code/my_app/Gemfile > ~/code/my_app/gem_ages.txt
 ```
-which will pipe the output into a text file.
 
-The command line output will look something like this:
+[TablePrint](https://github.com/arches/table_print) formats the output to something like this:
 
 ```bash
 NAME        | VERSION | DATE

lib/gem_dating/cli.rb

@@ -5,10 +5,15 @@ class Cli
 
     HELP_TEXT =
       <<~HELP
-        Usage: gem_dating [--help | -h] [<GEMFILE_FILEPATH>]
+        gem_dating [--help | -h] [<GEMFILE_FILEPATH>]
+
+        GEMFILE_FILEPATH defaults to ./Gemfile if not provided.
+
+        Options:
+          --help, -h  Show this help message
       HELP
 
-    def initialize(argv)
+    def initialize(argv = [])
       args, file_path = argv.partition { |arg| (arg =~ /--\w+/) || (arg =~ /(-[a-z])/) }
 
       @args = args
@@ -22,8 +27,15 @@ def run
       end
 
       unless @file_path
-        $stdout << HELP_TEXT
-        return GENERAL_ERROR
+        current_directory = Dir.pwd
+        file_path = File.join(current_directory, "Gemfile")
+
+        if File.exist?(file_path)
+          @file_path = file_path
+        else
+          $stdout << HELP_TEXT
+          return GENERAL_ERROR
+        end
       end
 
       $stdout << GemDating.from_file(@file_path).table_print << "\n"

test/cli_test.rb

@@ -18,13 +18,21 @@ def setup
       s.version = "0.0.2227"
       s.date = DateTime.parse("2023-05-17")
     end
-  end
 
-  def test_gemfile
-    exit_code = nil
+    @tempdir = Dir.mktmpdir("gem_dating_test")
 
     Mocktail.replace(GemDating::Rubygems)
     stubs { |m| GemDating::Rubygems.fetch(m.is_a(Array)) }.with { [@spec1, @spec2, @spec3] }
+  end
+
+  def teardown
+    super
+    FileUtils.rm_rf @tempdir
+    Mocktail.reset
+  end
+
+  def test_gemfile
+    exit_code = nil
 
     stdout, _stderr = capture_io do
       exit_code = GemDating::Cli.new(["test/Gemfile.example"]).run
@@ -42,17 +50,42 @@ def test_gemfile
     assert_equal expected_out, stdout
   end
 
-  def test_no_args_prints_help
-    exit_code = nil
+  def test_default_to_existing_relative_gemfile
+    FileUtils.copy("test/Gemfile.example", "#{@tempdir}/Gemfile")
 
-    stdout, _stderr = capture_io do
-      exit_code = GemDating::Cli.new([]).run
+    Dir.chdir(@tempdir) do
+      exit_code = nil
+
+      stdout, _stderr = capture_io do
+        exit_code = GemDating::Cli.new.run
+      end
+
+      expected_out = <<~EXPECTED
+      NAME            | VERSION  | DATE      
+      ----------------|----------|-----------
+      banana-client   | 21.1.0   | 1990-08-21
+      rails-on-rubies | 70.0.5   | 2123-05-24
+      giraffeql       | 0.0.2227 | 2023-05-17
+    EXPECTED
+
+      assert_equal 0, exit_code
+      assert_equal expected_out, stdout
     end
+  end
 
-    expected_out = GemDating::Cli::HELP_TEXT
+  def test_no_default_gemfile
+    Dir.chdir(@tempdir) do
+      exit_code = nil
 
-    assert_equal 1, exit_code
-    assert_equal expected_out, stdout
+      stdout, _stderr = capture_io do
+        exit_code = GemDating::Cli.new([]).run
+      end
+
+      expected_out = GemDating::Cli::HELP_TEXT
+
+      assert_equal 1, exit_code
+      assert_equal expected_out, stdout
+    end
   end
 
   def test_bad_filepath