Enhance color and database support; add environment variable handling for GIT_DIR and GIT_PKGS_DB

Author: andrew

CHANGELOG.md

@@ -2,11 +2,11 @@
 
 - Pager support for long output (respects `GIT_PAGER`, `core.pager`, `PAGER`)
 - `--no-pager` option for commands with long output
+- Colored output (respects `NO_COLOR`, `color.ui`, `color.pkgs`)
+- `GIT_DIR` and `GIT_PKGS_DB` environment variable support
 - `git pkgs stats` now supports `--since` and `--until` date filters
 - Consistent error handling across all commands (JSON errors when `--format=json`)
 - `git pkgs update` now uses a transaction for atomicity and better performance
-- `GIT_PKGS_DB` environment variable to customize database location
-- Colored output for diff, show, and history commands (respects `NO_COLOR`)
 - Renamed `git pkgs outdated` to `git pkgs stale` (outdated remains as alias)
 - `git pkgs log` command to list commits with dependency changes
 - `git pkgs schema` command to output database schema in text, SQL, JSON, or markdown

README.md

@@ -37,7 +37,7 @@ git pkgs diff --from=main --to=feature  # compare branches
 git pkgs init
 ```
 
-Walks through git history and builds a SQLite database of dependency changes, stored in `.git/pkgs.sqlite3`. Set `GIT_PKGS_DB` environment variable to use a custom location.
+Walks through git history and builds a SQLite database of dependency changes, stored in `.git/pkgs.sqlite3`.
 
 Options:
 - `--branch=NAME` - analyze a specific branch (default: default branch)
@@ -328,38 +328,18 @@ jobs:
       - run: git pkgs diff --from=origin/${{ github.base_ref }} --to=HEAD
 ```
 
-## Colors
+## Configuration
 
-Output is colored when writing to a terminal. Colors are automatically disabled when piping to another command or redirecting to a file.
+git-pkgs respects [standard git configuration](https://git-scm.com/docs/git-config).
 
-To disable colors explicitly:
+**Colors** are enabled when writing to a terminal. Disable with `NO_COLOR=1`, `git config color.ui never`, or `git config color.pkgs never` for git-pkgs only.
 
-```bash
-NO_COLOR=1 git pkgs diff --from=HEAD~10
-```
-
-Or set `NO_COLOR` in your shell profile to disable colors permanently. See [no-color.org](https://no-color.org/) for details.
-
-## Pager
-
-Long output is piped through a pager, following git's precedence:
-
-1. `GIT_PAGER` environment variable
-2. `core.pager` git config
-3. `PAGER` environment variable
-4. `less -FRSX` as fallback
+**Pager** follows git's precedence: `GIT_PAGER` env, `core.pager` config, `PAGER` env, then `less -FRSX`. Use `--no-pager` flag or `git config core.pager cat` to disable.
 
-To disable paging for a single command:
+**Environment variables:**
 
-```bash
-git pkgs history --no-pager
-```
-
-To disable paging entirely, set your pager to `cat` or empty string:
-
-```bash
-git config core.pager cat
-```
+- `GIT_DIR` - git directory location (standard git variable)
+- `GIT_PKGS_DB` - database path (default: `.git/pkgs.sqlite3`)
 
 ## Performance
 

lib/git/pkgs/color.rb

@@ -24,12 +24,43 @@ def self.enabled=(value)
         @enabled = value
       end
 
+      def self.reset!
+        remove_instance_variable(:@enabled) if defined?(@enabled)
+      end
+
       def self.determine_color_support
-        return false unless $stdout.respond_to?(:tty?) && $stdout.tty?
+        # NO_COLOR takes precedence (https://no-color.org/)
         return false if ENV["NO_COLOR"] && !ENV["NO_COLOR"].empty?
         return false if ENV["TERM"] == "dumb"
 
-        true
+        # Check git config: color.pkgs takes precedence over color.ui
+        git_color = git_color_config
+        case git_color
+        when "always" then return true
+        when "never" then return false
+        # "auto" falls through to TTY check
+        end
+
+        $stdout.respond_to?(:tty?) && $stdout.tty?
+      end
+
+      def self.git_color_config
+        # color.pkgs overrides color.ui for git-pkgs specific control
+        pkgs_color = `git config --get color.pkgs 2>/dev/null`.chomp
+        return normalize_color_value(pkgs_color) unless pkgs_color.empty?
+
+        ui_color = `git config --get color.ui 2>/dev/null`.chomp
+        return normalize_color_value(ui_color) unless ui_color.empty?
+
+        "auto"
+      end
+
+      def self.normalize_color_value(value)
+        case value.downcase
+        when "true", "always" then "always"
+        when "false", "never" then "never"
+        else "auto"
+        end
       end
 
       def self.colorize(text, *codes)

lib/git/pkgs/database.rb

@@ -17,6 +17,14 @@ def self.path(git_dir = nil)
       end
 
       def self.find_git_dir
+        # Respect GIT_DIR environment variable
+        if ENV["GIT_DIR"] && !ENV["GIT_DIR"].empty?
+          git_dir = ENV["GIT_DIR"]
+          return git_dir if File.directory?(git_dir)
+
+          raise NotInGitRepoError, "GIT_DIR '#{git_dir}' does not exist"
+        end
+
         dir = Dir.pwd
         loop do
           git_dir = File.join(dir, ".git")

lib/git/pkgs/repository.rb

@@ -7,9 +7,9 @@ module Pkgs
     class Repository
       attr_reader :path
 
-      def initialize(path = Dir.pwd)
-        @path = path
-        @rugged = Rugged::Repository.new(path)
+      def initialize(path = nil)
+        @path = path || ENV["GIT_DIR"] || Dir.pwd
+        @rugged = Rugged::Repository.new(@path)
       end
 
       def git_dir

test/git/pkgs/test_color.rb

@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class Git::Pkgs::TestColor < Minitest::Test
+  def setup
+    @original_env = {
+      "NO_COLOR" => ENV["NO_COLOR"],
+      "TERM" => ENV["TERM"]
+    }
+    Git::Pkgs::Color.reset!
+  end
+
+  def teardown
+    @original_env.each do |key, value|
+      if value
+        ENV[key] = value
+      else
+        ENV.delete(key)
+      end
+    end
+    Git::Pkgs::Color.reset!
+  end
+
+  def test_no_color_env_disables_color
+    ENV["NO_COLOR"] = "1"
+    Git::Pkgs::Color.reset!
+
+    refute Git::Pkgs::Color.enabled?
+  end
+
+  def test_term_dumb_disables_color
+    ENV.delete("NO_COLOR")
+    ENV["TERM"] = "dumb"
+    Git::Pkgs::Color.reset!
+
+    refute Git::Pkgs::Color.enabled?
+  end
+
+  def test_colorize_returns_plain_text_when_disabled
+    Git::Pkgs::Color.enabled = false
+
+    assert_equal "hello", Git::Pkgs::Color.red("hello")
+    assert_equal "world", Git::Pkgs::Color.green("world")
+  end
+
+  def test_colorize_returns_ansi_codes_when_enabled
+    Git::Pkgs::Color.enabled = true
+
+    assert_equal "\e[31mhello\e[0m", Git::Pkgs::Color.red("hello")
+    assert_equal "\e[32mworld\e[0m", Git::Pkgs::Color.green("world")
+    assert_equal "\e[33mtest\e[0m", Git::Pkgs::Color.yellow("test")
+  end
+
+  def test_normalize_color_value
+    assert_equal "always", Git::Pkgs::Color.normalize_color_value("true")
+    assert_equal "always", Git::Pkgs::Color.normalize_color_value("always")
+    assert_equal "always", Git::Pkgs::Color.normalize_color_value("TRUE")
+    assert_equal "never", Git::Pkgs::Color.normalize_color_value("false")
+    assert_equal "never", Git::Pkgs::Color.normalize_color_value("never")
+    assert_equal "never", Git::Pkgs::Color.normalize_color_value("FALSE")
+    assert_equal "auto", Git::Pkgs::Color.normalize_color_value("auto")
+    assert_equal "auto", Git::Pkgs::Color.normalize_color_value("anything")
+  end
+end

test/git/pkgs/test_repository.rb

@@ -6,13 +6,20 @@ class Git::Pkgs::TestRepository < Minitest::Test
   include TestHelpers
 
   def setup
+    @original_git_dir = ENV["GIT_DIR"]
+    ENV.delete("GIT_DIR")
     create_test_repo
     add_file("README.md", "# Test")
     commit("Initial commit")
   end
 
   def teardown
     cleanup_test_repo
+    if @original_git_dir
+      ENV["GIT_DIR"] = @original_git_dir
+    else
+      ENV.delete("GIT_DIR")
+    end
   end
 
   def test_initializes_with_path
@@ -95,4 +102,12 @@ def test_rev_parse_returns_nil_for_invalid_ref
 
     assert_nil sha
   end
+
+  def test_respects_git_dir_env
+    git_dir = File.join(@test_dir, ".git")
+    ENV["GIT_DIR"] = git_dir
+
+    repo = Git::Pkgs::Repository.new
+    assert_equal git_dir, repo.path
+  end
 end