Auto merge of #4487 - b-ggs:show-executables-man-page, r=segiddins

Show executable's man page when --help or -h is present

Fixes #4480, where `bundle exec foo --help` shows `bundle exec`'s man instead of `foo`'s man.

@RochesterinNYC

2 files changed, 135 insertions, 3 deletions

diff --git a/lib/bundler/cli.rb b/lib/bundler/cli.rb
index 9834277cd8..758decfa24 100644
--- a/lib/bundler/cli.rb
+++ b/lib/bundler/cli.rb
@@ -437,13 +437,37 @@ module Bundler
     # into the corresponding `bundle help #{command}` call
     def self.reformatted_help_args(args)
       bundler_commands = all_commands.keys
+      help_flags = %w(--help -h)
+      exec_commands = %w(exec e)
+      help_used = args.select {|a| help_flags.include? a }
+      exec_used = args.select {|a| exec_commands.include? a }
       command = args.select {|a| bundler_commands.include? a }
-      if command.empty?
+      if exec_used.any? && help_used.any?
+        regex = /
+            ( # Matches `exec --help` or `exec --help foo`
+              (#{exec_commands.join("|")})
+              \s
+              (#{help_flags.join("|")})
+              (.+)*
+            )|
+            ( # Matches `--help exec` or `--help exec foo`
+              (#{help_flags.join("|")})
+              \s
+              (#{exec_commands.join("|")})
+              (.+)*
+            )
+          /x
+        arg_str = args.join(" ")
+        if arg_str =~ regex
+          %w(help exec)
+        else
+          args
+        end
+      elsif command.empty?
         abort("Could not find command \"#{args.join(" ")}\".")
       else
-        command = command.first
+        ["help", command.first]
       end
-      ["help", command]
     end
 
   private
diff --git a/spec/commands/exec_spec.rb b/spec/commands/exec_spec.rb
index e2ae0aabbb..69e468e711 100644
--- a/spec/commands/exec_spec.rb
+++ b/spec/commands/exec_spec.rb
@@ -218,6 +218,114 @@ describe "bundle exec" do
     expect(out).to include("bundler: exec needs a command to run")
   end
 
+  describe "with help flags" do
+    describe "when exec is used" do
+      before(:each) do
+        install_gemfile <<-G
+          gem "rack"
+        G
+      end
+
+      it "shows executable's man page when --help is after the executable" do
+        bundle "exec cat --help"
+        expect(out).to include("Usage: cat [OPTION]... [FILE]...")
+      end
+
+      it "uses executable's original behavior for -h" do
+        bundle "exec cat -h"
+        expect(err).to include("cat: invalid option -- 'h'")
+      end
+
+      it "shows bundle-exec's man page when --help is between exec and the executable" do
+        with_fake_man do
+          bundle "exec --help cat"
+        end
+        expect(out).to include(%(["#{root}/lib/bundler/man/bundle-exec"]))
+      end
+
+      it "shows bundle-exec's man page when --help is before exec" do
+        with_fake_man do
+          bundle "--help exec"
+        end
+        expect(out).to include(%(["#{root}/lib/bundler/man/bundle-exec"]))
+      end
+
+      it "shows bundle-exec's man page when -h is before exec" do
+        with_fake_man do
+          bundle "-h exec"
+        end
+        expect(out).to include(%(["#{root}/lib/bundler/man/bundle-exec"]))
+      end
+
+      it "shows bundle-exec's man page when --help is after exec" do
+        with_fake_man do
+          bundle "exec --help"
+        end
+        expect(out).to include(%(["#{root}/lib/bundler/man/bundle-exec"]))
+      end
+
+      it "shows bundle-exec's man page when -h is after exec" do
+        with_fake_man do
+          bundle "exec -h"
+        end
+        expect(out).to include(%(["#{root}/lib/bundler/man/bundle-exec"]))
+      end
+    end
+
+    describe "when e is used" do
+      before(:each) do
+        install_gemfile <<-G
+          gem "rack"
+        G
+      end
+
+      it "shows executable's man page when --help is after the executable" do
+        bundle "e cat --help"
+        expect(out).to include("Usage: cat [OPTION]... [FILE]...")
+      end
+
+      it "uses executable's original behavior for -h" do
+        bundle "e cat -h"
+        expect(err).to include("cat: invalid option -- 'h'")
+      end
+
+      it "shows bundle-exec's man page when --help is between exec and the executable" do
+        with_fake_man do
+          bundle "e --help cat"
+        end
+        expect(out).to include(%(["#{root}/lib/bundler/man/bundle-exec"]))
+      end
+
+      it "shows bundle-exec's man page when --help is before exec" do
+        with_fake_man do
+          bundle "--help e"
+        end
+        expect(out).to include(%(["#{root}/lib/bundler/man/bundle-exec"]))
+      end
+
+      it "shows bundle-exec's man page when -h is before exec" do
+        with_fake_man do
+          bundle "-h e"
+        end
+        expect(out).to include(%(["#{root}/lib/bundler/man/bundle-exec"]))
+      end
+
+      it "shows bundle-exec's man page when --help is after exec" do
+        with_fake_man do
+          bundle "e --help"
+        end
+        expect(out).to include(%(["#{root}/lib/bundler/man/bundle-exec"]))
+      end
+
+      it "shows bundle-exec's man page when -h is after exec" do
+        with_fake_man do
+          bundle "e -h"
+        end
+        expect(out).to include(%(["#{root}/lib/bundler/man/bundle-exec"]))
+      end
+    end
+  end
+
   describe "with gem executables" do
     describe "run from a random directory" do
       before(:each) do