Require git repo location to be given

Whomever calls Hook::init should be responsible for saying where to
install. We also simplify things a bit by relying on a tempdir in the
tests.

Author: stevenharman

lib/git_tracker/hook.rb

@@ -2,38 +2,33 @@
 
 module GitTracker
   class Hook
-    attr_reader :hook_file
+    BODY = <<~HOOK.freeze
+      #!/usr/bin/env bash
 
-    def self.init
-      init_at(Repository.root)
-    end
+      if command -v git-tracker >/dev/null; then
+        git-tracker prepare-commit-msg "$@"
+      fi
+
+    HOOK
+
+    attr_reader :hook_file
 
-    def self.init_at(root)
-      new(root).write
+    def self.init(at:)
+      new(at: at).write
     end
 
-    def initialize(root)
-      @hook_file = File.join(root, ".git", "hooks", "prepare-commit-msg")
+    def initialize(at:)
+      @hook_file = Pathname(at).join(PREPARE_COMMIT_MSG_PATH)
     end
 
     def write
-      File.open(hook_file, "w") do |f|
-        f.write(hook_body)
+      hook_file.open("w") do |f|
+        f.write(BODY)
         f.chmod(0o755)
       end
     end
 
-    private
-
-    def hook_body
-      <<~HOOK
-        #!/usr/bin/env bash
-
-        if command -v git-tracker >/dev/null; then
-          git-tracker prepare-commit-msg "$@"
-        fi
-
-      HOOK
-    end
+    PREPARE_COMMIT_MSG_PATH = ".git/hooks/prepare-commit-msg".freeze
+    private_constant :PREPARE_COMMIT_MSG_PATH
   end
 end

lib/git_tracker/runner.rb

@@ -1,12 +1,15 @@
 require "git_tracker/prepare_commit_message"
 require "git_tracker/hook"
+require "git_tracker/repository"
 require "git_tracker/version"
 
 module GitTracker
   module Runner
     def self.execute(cmd_arg = "help", *args)
       command = cmd_arg.tr("-", "_")
+
       abort("[git_tracker] command: '#{cmd_arg}' does not exist.") unless respond_to?(command)
+
       send(command, *args)
     end
 
@@ -15,7 +18,7 @@ def self.prepare_commit_msg(*args)
     end
 
     def self.init
-      Hook.init
+      Hook.init(at: Repository.root)
     end
 
     def self.install

spec/git_tracker/hook_spec.rb

@@ -1,51 +1,26 @@
 require "git_tracker/hook"
-require "active_support/core_ext/string/strip"
 
 RSpec.describe GitTracker::Hook do
-  subject(:hook) { described_class }
-  let(:root) { "/path/to/git/repo/toplevel" }
-  let(:hook_path) { File.join(root, ".git", "hooks", "prepare-commit-msg") }
-
-  describe ".init" do
-    before do
-      allow(GitTracker::Repository).to receive(:root) { root }
-      allow(hook).to receive(:init_at)
-    end
-
-    it "initializes to the root of the Git repository" do
-      hook.init
-      expect(hook).to have_received(:init_at).with(root)
+  subject(:hook) { described_class.new(at: Pathname(@repo_root_dir)) }
+
+  around do |example|
+    Dir.mktmpdir do |dir|
+      @repo_root_dir = dir
+      hooks_dir = Pathname(dir).join(".git/hooks")
+      FileUtils.mkdir_p(hooks_dir)
+      example.call
     end
   end
 
-  describe ".init_at" do
-    let(:fake_file) { GitTracker::FakeFile.new }
-    before do
-      allow(File).to receive(:open).and_yield(fake_file)
-    end
-
-    it "writes the hook into the hooks directory" do
-      hook.init_at(root)
-      expect(File).to have_received(:open).with(hook_path, "w")
-    end
+  it "makes the hook executable" do
+    hook.write
 
-    it "makes the hook executable" do
-      hook.init_at(root)
-      expect(fake_file.mode).to eq(0o755)
-    end
-
-    it "writes the hook code in the hook file" do
-      hook_code = <<-HOOK_CODE.strip_heredoc
-        #!/usr/bin/env bash
-
-        if command -v git-tracker >/dev/null; then
-          git-tracker prepare-commit-msg "$@"
-        fi
+    expect(hook.hook_file).to be_executable
+  end
 
-      HOOK_CODE
+  it "writes the hook code in the hook file" do
+    hook.write
 
-      hook.init_at(root)
-      expect(fake_file.content).to eq(hook_code)
-    end
+    expect(hook.hook_file.read).to eq(described_class::BODY)
   end
 end

spec/git_tracker/runner_spec.rb

@@ -12,7 +12,7 @@
     end
 
     it "runs the hook, passing the args" do
-      expect(runner).to receive(:prepare_commit_msg).with(*args) { true }
+      expect(runner).to receive(:prepare_commit_msg).with(*args)
       runner.execute("prepare-commit-msg", *args)
     end
 
@@ -26,14 +26,17 @@
 
   describe ".prepare_commit_msg" do
     it "runs the hook, passing the args" do
-      expect(GitTracker::PrepareCommitMessage).to receive(:run).with(*args) { true }
+      expect(GitTracker::PrepareCommitMessage).to receive(:run).with(*args)
       runner.prepare_commit_msg(*args)
     end
   end
 
   describe ".init" do
+    let(:repo_root) { "/path/to/git/repo/root" }
+
     it "tells the hook to initialize itself" do
-      expect(GitTracker::Hook).to receive(:init)
+      allow(GitTracker::Repository).to receive(:root) { repo_root }
+      expect(GitTracker::Hook).to receive(:init).with(at: repo_root)
       runner.init
     end
   end