Hint at new location of migrated formulae

Partial implementation of
https://github.com/Homebrew/brew-evolution/pull/15, along with the ability to
search for deleted formulae in git history (inspired by #1996) which is not
described in the proposal.

See also: #1371.

1 files changed, 46 insertions, 0 deletions

diff --git a/Library/Homebrew/test/historic_test.rb b/Library/Homebrew/test/historic_test.rb
new file mode 100644
index 000000000..d09656fe0
--- /dev/null
+++ b/Library/Homebrew/test/historic_test.rb
@@ -0,0 +1,46 @@
+require "testing_env"
+require "historic"
+
+class HistoricTest < Homebrew::TestCase
+  def setup
+    super
+
+    @path = Tap::TAP_DIRECTORY/"homebrew/homebrew-foo"
+    @path.mkpath
+    @tap = Tap.new("Homebrew", "foo")
+
+    (@path/"tap_migrations.json").write <<-EOS.undent
+      { "migrated-formula": "homebrew/bar" }
+    EOS
+    (@path/"Formula/to-delete.rb").write "placeholder"
+
+    @path.cd do
+      shutup do
+        system "git", "init"
+        system "git", "add", "--all"
+        system "git", "commit", "-m", "initial state"
+        system "git", "rm", "Formula/to-delete.rb"
+        system "git", "commit", "-m", "delete formula 'to-delete'"
+      end
+    end
+  end
+
+  def teardown
+    @path.rmtree
+
+    super
+  end
+
+  def test_search_for_migrated_formula
+    migrations = Homebrew.search_for_migrated_formula("migrated-formula", print_messages: false)
+    assert_equal [[@tap, "homebrew/bar"]], migrations
+  end
+
+  def test_search_for_deleted_formula
+    tap, relpath, hash, = Homebrew.search_for_deleted_formula("homebrew/foo/to-delete",
+                                                              print_messages: false)
+    assert_equal tap, @tap
+    assert_equal relpath, "Formula/to-delete.rb"
+    assert_equal `git rev-parse HEAD`.chomp, hash
+  end
+end