--repository: support to show tap path

This can become handy when we separate core code and formulae. For
example, we could use `cd $(brew --repo homebrew/core)` to go to core
tap path.

Closes Homebrew/homebrew#50346.

Signed-off-by: Xu Cheng <xucheng@me.com>

3 files changed, 15 insertions, 1 deletions

diff --git a/Library/Homebrew/cmd/--repository.rb b/Library/Homebrew/cmd/--repository.rb
index e2a5feb13..b697b3eaa 100644
--- a/Library/Homebrew/cmd/--repository.rb
+++ b/Library/Homebrew/cmd/--repository.rb
@@ -1,5 +1,11 @@
+require "tap"
+
 module Homebrew
   def __repository
-    puts HOMEBREW_REPOSITORY
+    if ARGV.named.empty?
+      puts HOMEBREW_REPOSITORY
+    else
+      puts ARGV.named.map { |tap| Tap.fetch(tap).path }
+    end
   end
 end
diff --git a/Library/Homebrew/manpages/brew.1.md b/Library/Homebrew/manpages/brew.1.md
index d884d6702..aa88b373d 100644
--- a/Library/Homebrew/manpages/brew.1.md
+++ b/Library/Homebrew/manpages/brew.1.md
@@ -529,6 +529,9 @@ With `--verbose` or `-v`, many commands print extra debugging information. Note
     Display where Homebrew's `.git` directory is located. For standard installs,
     the `prefix` and `repository` are the same directory.
 
+  * `--repository` <user>`/`<repo>:
+    Display where tap <user>`/`<repo>'s directory is located.
+
   * `--version`:
     Print the version number of brew to standard error and exit.
 
diff --git a/Library/Homebrew/test/test_integration_cmds.rb b/Library/Homebrew/test/test_integration_cmds.rb
index 52606da08..8a7c85551 100644
--- a/Library/Homebrew/test/test_integration_cmds.rb
+++ b/Library/Homebrew/test/test_integration_cmds.rb
@@ -124,6 +124,11 @@ class IntegrationCommandTests < Homebrew::TestCase
                  cmd("--repository")
   end
 
+  def test_repository
+    assert_match "#{HOMEBREW_LIBRARY}/Taps/foo/homebrew-bar",
+                 cmd("--repository", "foo/bar")
+  end
+
   def test_help
     assert_match "Example usage:",
                  cmd("help")