From b308a6227650e397102fa8fe3e3809af2630cd1e Mon Sep 17 00:00:00 2001
From: Andrey Marchenko <andrey.marchenko@datadoghq.com>
Date: Thu, 4 Jan 2024 13:41:42 +0100
Subject: [PATCH] add Utils::Git.relative_to_root method to return source file
 paths relative to git repo's root

---
 lib/datadog/ci/utils/git.rb       | 13 ++++++++++
 sig/datadog/ci/utils/git.rbs      |  8 ++++--
 spec/datadog/ci/utils/git_spec.rb | 41 +++++++++++++++++++++++++++++++
 3 files changed, 60 insertions(+), 2 deletions(-)

diff --git a/lib/datadog/ci/utils/git.rb b/lib/datadog/ci/utils/git.rb
index 4f89a56e..108b971a 100644
--- a/lib/datadog/ci/utils/git.rb
+++ b/lib/datadog/ci/utils/git.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require "open3"
+require "pathname"
 
 module Datadog
   module CI
@@ -25,6 +26,18 @@ def self.root
           @@root = exec_git_command("git rev-parse --show-toplevel")
         end
 
+        def self.relative_to_root(path)
+          return nil if path.nil?
+
+          git_root = root
+          return path if git_root.nil?
+
+          path = Pathname.new(File.expand_path(path))
+          git_root = Pathname.new(git_root)
+
+          path.relative_path_from(git_root).to_s
+        end
+
         def self.exec_git_command(cmd)
           out, status = Open3.capture2e(cmd)
 
diff --git a/sig/datadog/ci/utils/git.rbs b/sig/datadog/ci/utils/git.rbs
index 4ef0a783..b413f3bc 100644
--- a/sig/datadog/ci/utils/git.rbs
+++ b/sig/datadog/ci/utils/git.rbs
@@ -4,11 +4,15 @@ module Datadog
       module Git
         @@root: String?
 
-        def self?.normalize_ref: (untyped name) -> (nil | untyped)
+        def self.normalize_ref: (String? name) -> String?
 
-        def self?.is_git_tag?: (untyped ref) -> untyped
+        def self.is_git_tag?: (String? ref) -> bool
 
         def self.exec_git_command: (String ref) -> String?
+
+        def self.root: -> String?
+
+        def self.relative_to_root: (String? path) -> String?
       end
     end
   end
diff --git a/spec/datadog/ci/utils/git_spec.rb b/spec/datadog/ci/utils/git_spec.rb
index 0c6cb14f..770f69d0 100644
--- a/spec/datadog/ci/utils/git_spec.rb
+++ b/spec/datadog/ci/utils/git_spec.rb
@@ -64,4 +64,45 @@
       end
     end
   end
+
+  describe ".relative_to_root" do
+    subject { described_class.relative_to_root(path) }
+
+    context "when path is nil" do
+      let(:path) { nil }
+
+      it { is_expected.to be_nil }
+    end
+
+    context "when git root is nil" do
+      before do
+        allow(described_class).to receive(:root).and_return(nil)
+      end
+
+      let(:path) { "foo/bar" }
+
+      it { is_expected.to eq("foo/bar") }
+    end
+
+    context "when git root is not nil" do
+      context "when path is absolute" do
+        before do
+          allow(described_class).to receive(:root).and_return("/foo/bar")
+        end
+        let(:path) { "/foo/bar/baz" }
+
+        it { is_expected.to eq("baz") }
+      end
+
+      context "when path is relative" do
+        before do
+          allow(described_class).to receive(:root).and_return("#{Dir.pwd}/foo/bar")
+        end
+
+        let(:path) { "./baz" }
+
+        it { is_expected.to eq("../../baz") }
+      end
+    end
+  end
 end