Merge pull request #5530 from GauthamGoli/helptext-for-invalid-opt

cli_parser: Output help text on invalid option passed

Library/Homebrew/cli_parser.rb

@@ -123,7 +123,12 @@ module Homebrew
       end
 
       def parse(cmdline_args = ARGV)
-        remaining_args = @parser.parse(cmdline_args)
+        begin
+          remaining_args = @parser.parse(cmdline_args)
+        rescue OptionParser::InvalidOption => e
+          $stderr.puts generate_help_text
+          raise e
+        end
         check_constraint_violations
         Homebrew.args[:remaining] = remaining_args
         Homebrew.args.freeze

Library/Homebrew/test/cli_parser_spec.rb

@@ -11,8 +11,8 @@ describe Homebrew::CLI::Parser do
     }
 
     before do
+      allow(ENV).to receive(:[])
       allow(ENV).to receive(:[]).with("HOMEBREW_PRY").and_return("1")
-      allow(ENV).to receive(:[]).with("HOMEBREW_VERBOSE")
     end
 
     it "parses short option" do
@@ -38,8 +38,9 @@ describe Homebrew::CLI::Parser do
       expect(Homebrew.args.more_verbose?).to be nil
     end
 
-    it "raises an exception when an invalid option is passed" do
+    it "raises an exception and outputs help text when an invalid option is passed" do
       expect { parser.parse(["--random"]) }.to raise_error(OptionParser::InvalidOption, /--random/)
+                                           .and output(/Usage: brew/).to_stderr
     end
 
     it "maps environment var to an option" do