Added clear git version cache method

Library/Homebrew/test/utils/git_spec.rb

@@ -1,44 +1,39 @@
 require "utils/git"
 
 describe Git do
-  before(:all) do
+  before(:each) do
     git = HOMEBREW_SHIMS_PATH/"scm/git"
 
-    @file = "lib/blah.rb"
+    @file = "blah.rb"
-    @repo = Pathname.new("repo")
 
-    (@repo/"lib").mkpath
+    HOMEBREW_CACHE.cd do
       system git, "init"
-    FileUtils.touch(@repo/@file)
 
-    File.open(@repo/@file, "w") { |f| f.write("blah") }
+      File.open(@file, "w") { |f| f.write("blah") }
-    system git, "add", @repo/@file
+      system git, "add", HOMEBREW_CACHE/@file
       system git, "commit", "-m", "'File added'"
       @h1 = `git rev-parse HEAD`
 
-    File.open(@repo/@file, "w") { |f| f.write("brew") }
+      File.open(@file, "w") { |f| f.write("brew") }
-    system git, "add", @repo/@file
+      system git, "add", HOMEBREW_CACHE/@file
       system git, "commit", "-m", "'written to File'"
       @h2 = `git rev-parse HEAD`
     end
+  end
 
   let(:hash1) { @h1[0..6] }
   let(:hash2) { @h2[0..6] }
 
-  after(:all) do
-    FileUtils.rm_rf(@repo)
-  end
-
   describe "#last_revision_commit_of_file" do
     it "gives last revision commit when before_commit is nil" do
       expect(
-        described_class.last_revision_commit_of_file(@repo, @file),
+        described_class.last_revision_commit_of_file(HOMEBREW_CACHE, @file),
       ).to eq(hash1)
     end
 
     it "gives revision commit based on before_commit when it is not nil" do
       expect(
-        described_class.last_revision_commit_of_file(@repo,
+        described_class.last_revision_commit_of_file(HOMEBREW_CACHE,
                                                     @file,
                                                     before_commit: hash2),
       ).to eq(hash2)
@@ -48,14 +43,14 @@ describe Git do
   describe "#last_revision_of_file" do
     it "returns last revision of file" do
       expect(
-        described_class.last_revision_of_file(@repo,
+        described_class.last_revision_of_file(HOMEBREW_CACHE,
-                                              @repo/@file),
+                                              HOMEBREW_CACHE/@file),
       ).to eq("blah")
     end
 
     it "returns last revision of file based on before_commit" do
       expect(
-        described_class.last_revision_of_file(@repo, @repo/@file,
+        described_class.last_revision_of_file(HOMEBREW_CACHE, HOMEBREW_CACHE/@file,
                                               before_commit: "0..3"),
       ).to eq("brew")
     end
@@ -64,9 +59,7 @@ end
 
 describe Utils do
   before(:each) do
-    if described_class.instance_variable_defined?(:@git)
+    described_class.clear_git_version_cache
-      described_class.send(:remove_instance_variable, :@git)
-    end
   end
 
   describe "::git_available?" do
@@ -75,14 +68,14 @@ describe Utils do
     end
 
     it "returns false if git --version command does not succeed" do
-      stub_const("HOMEBREW_SHIMS_PATH", mktmpdir/"shim")
+      stub_const("HOMEBREW_SHIMS_PATH", HOMEBREW_PREFIX/"bin/shim")
       expect(described_class.git_available?).to be_falsey
     end
   end
 
   describe "::git_path" do
     it "returns nil when git is not available" do
-      stub_const("HOMEBREW_SHIMS_PATH", mktmpdir/"shim")
+      stub_const("HOMEBREW_SHIMS_PATH", HOMEBREW_PREFIX/"bin/shim")
       expect(described_class.git_path).to eq(nil)
     end
 
@@ -93,7 +86,7 @@ describe Utils do
 
   describe "::git_version" do
     it "returns nil when git is not available" do
-      stub_const("HOMEBREW_SHIMS_PATH", mktmpdir/"shim")
+      stub_const("HOMEBREW_SHIMS_PATH", HOMEBREW_PREFIX/"bin/shim")
       expect(described_class.git_path).to eq(nil)
     end
 
@@ -109,7 +102,7 @@ describe Utils do
 
     context "when git is not already available" do
       before do
-        stub_const("HOMEBREW_SHIMS_PATH", mktmpdir/"shim")
+        stub_const("HOMEBREW_SHIMS_PATH", HOMEBREW_PREFIX/"bin/shim")
       end
 
       it "can't install brewed git if homebrew/core is unavailable" do
@@ -118,7 +111,7 @@ describe Utils do
       end
 
       it "raises error if can't install git" do
-        stub_const("HOMEBREW_BREW_FILE", mktmpdir/"brew")
+        stub_const("HOMEBREW_BREW_FILE", HOMEBREW_PREFIX/"bin/brew")
         expect { described_class.ensure_git_installed! }.to raise_error("Git is unavailable")
       end
 
@@ -131,24 +124,23 @@ describe Utils do
 
   describe "::git_remote_exists" do
     it "returns true when git is not available" do
-      stub_const("HOMEBREW_SHIMS_PATH", mktmpdir/"shim")
+      stub_const("HOMEBREW_SHIMS_PATH", HOMEBREW_PREFIX/"bin/shim")
       expect(described_class.git_remote_exists("blah")).to be_truthy
     end
 
     context "when git is available" do
       it "returns true when git remote exists", :needs_network do
         git = HOMEBREW_SHIMS_PATH/"scm/git"
-        repo = Pathname.new("hey")
+        url = "http://github.com/Homebrew/homebrew.github.io"
+        repo = HOMEBREW_CACHE/"hey"
         repo.mkpath
 
-        system "cd", repo
+        repo.cd do
           system git, "init"
-        system git, "remote", "add", "origin", "http://github.com/Homebrew/homebrew.github.io"
+          system git, "remote", "add", "origin", url
-        system "cd .."
+        end
 
-        expect(described_class.git_remote_exists("http://github.com/Homebrew/homebrew.github.io")).to be_truthy
+        expect(described_class.git_remote_exists(url)).to be_truthy
-
-        FileUtils.rm_rf(repo)
       end
 
       it "returns false when git remote does not exist" do

Library/Homebrew/utils/git.rb

@@ -19,13 +19,17 @@ module Git
     commit_hash = last_revision_commit_of_file(repo, relative_file, before_commit: before_commit)
     out, = Open3.capture3(
       HOMEBREW_SHIMS_PATH/"scm/git", "-C", repo,
-      "show", "#{commit_hash}:#{file}"
+      "show", "#{commit_hash}:#{relative_file}"
     )
     out
   end
 end
 
 module Utils
+  def self.clear_git_version_cache
+    remove_instance_variable(:@git) if instance_variable_defined?(:@git)
+  end
+
   def self.git_available?
     return @git if instance_variable_defined?(:@git)
     @git = quiet_system HOMEBREW_SHIMS_PATH/"scm/git", "--version"