From 5dcce02a3af17000e71521a0c0ca82456e6c47be Mon Sep 17 00:00:00 2001
From: Matt Clarkson <matthew.clarkson@arm.com>
Date: Mon, 8 Apr 2024 17:14:27 +0100
Subject: [PATCH] feat: implement `git config $NAME $VALUE`

This is needed to set `core.compression` to `9` in `rules_git`.

Nothing else is implemented other than setting repository
local configurations.
---
 cmd/bazel-git/BUILD.bazel |  2 ++
 cmd/bazel-git/cat-file.go |  1 +
 cmd/bazel-git/config.go   | 43 +++++++++++++++++++++++++++++++
 config/BUILD.bazel        | 19 ++++++++++++++
 config/set.go             | 53 +++++++++++++++++++++++++++++++++++++++
 config/set_test.go        | 32 +++++++++++++++++++++++
 6 files changed, 150 insertions(+)
 create mode 100644 cmd/bazel-git/config.go
 create mode 100644 config/BUILD.bazel
 create mode 100644 config/set.go
 create mode 100644 config/set_test.go

diff --git a/cmd/bazel-git/BUILD.bazel b/cmd/bazel-git/BUILD.bazel
index 8997861..4b59524 100644
--- a/cmd/bazel-git/BUILD.bazel
+++ b/cmd/bazel-git/BUILD.bazel
@@ -6,6 +6,7 @@ go_library(
     srcs = [
         "cat-file.go",
         "checkout.go",
+        "config.go",
         "error.go",
         "fetch.go",
         "init.go",
@@ -16,6 +17,7 @@ go_library(
     visibility = ["//visibility:private"],
     deps = [
         "//checkout",
+        "//config",
         "//fetch",
         "//object",
         "//reference",
diff --git a/cmd/bazel-git/cat-file.go b/cmd/bazel-git/cat-file.go
index 36fda48..b1e67cc 100644
--- a/cmd/bazel-git/cat-file.go
+++ b/cmd/bazel-git/cat-file.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"log/slog"
 
 	"github.com/jessevdk/go-flags"
diff --git a/cmd/bazel-git/config.go b/cmd/bazel-git/config.go
new file mode 100644
index 0000000..6680caa
--- /dev/null
+++ b/cmd/bazel-git/config.go
@@ -0,0 +1,43 @@
+package main
+
+import (
+	"log/slog"
+
+	"github.com/jessevdk/go-flags"
+	"gitlab.arm.com/bazel/git/v1/config"
+)
+
+type ConfigCommand struct {
+	Args struct {
+		Name  string `positional-arg-name:"<name>" description:"The configuration option name." required:"yes"`
+		Value string `positional-arg-name:"<value>" description:"The configuration option value." required:"yes"`
+	} `positional-args:"yes"`
+}
+
+var configCommand ConfigCommand
+
+func (x *ConfigCommand) Execute(rest []string) error {
+	if len(rest) != 0 {
+		return &flags.Error{flags.ErrDuplicatedFlag, "unsupported number of positional arguments"}
+	}
+
+	log := slog.With("name", x.Args.Name, "value", x.Args.Value)
+	log.Debug("set")
+	err := config.Set(config.SetOptions{
+		GitDir: options.Dir,
+		Name:   x.Args.Name,
+		Value:  x.Args.Value,
+	})
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func init() {
+	parser.AddCommand("config",
+		"Set repository options.",
+		`Sets repository options using a dot-separated key and value pair.`,
+		&configCommand)
+}
diff --git a/config/BUILD.bazel b/config/BUILD.bazel
new file mode 100644
index 0000000..e20eea5
--- /dev/null
+++ b/config/BUILD.bazel
@@ -0,0 +1,19 @@
+load("@rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "config",
+    srcs = ["set.go"],
+    importpath = "gitlab.arm.com/bazel/git/v1/config",
+    visibility = ["//visibility:public"],
+    deps = ["@com_github_go_git_go_git_v5//:go_default_library"],
+)
+
+go_test(
+    name = "config_test",
+    srcs = ["set_test.go"],
+    embed = [":config"],
+    deps = [
+        "@com_github_go_git_go_git_v5//:go_default_library",
+        "@com_github_stretchr_testify//assert:go_default_library",
+    ],
+)
diff --git a/config/set.go b/config/set.go
new file mode 100644
index 0000000..6e91532
--- /dev/null
+++ b/config/set.go
@@ -0,0 +1,53 @@
+package config
+
+import (
+	"errors"
+	"fmt"
+	"log/slog"
+	"strings"
+
+	"github.com/go-git/go-git/v5"
+)
+
+type SetOptions struct {
+	GitDir string
+	Name   string
+	Value  string
+}
+
+func Set(options SetOptions) (err error) {
+	log := slog.With("namespace", "config.Set", "name", options.Name, "value", options.Value)
+
+	log.Debug("open", "git-dir", options.GitDir)
+	repo, err := git.PlainOpen(options.GitDir)
+	if err != nil {
+		log.Error("open", "err", err)
+		return err
+	}
+	config, err := repo.Config()
+	if err != nil {
+		log.Error("config", "err", err)
+		return err
+	}
+
+	if config.Raw == nil {
+		return errors.New("Unexpected empty raw configuration value")
+	}
+
+	parts := strings.Split(options.Name, ".")
+	log.Debug("split", "parts", parts)
+	if len(parts) != 2 {
+		return fmt.Errorf("Invalid configuration value name: %s", options.Name)
+	}
+
+	section, name := parts[0], parts[1]
+
+	if !config.Raw.HasSection(section) {
+		return fmt.Errorf("`%s` section not found: %s", options.Name, section)
+	}
+	s := config.Raw.Section(section)
+
+	s.SetOption(name, options.Value)
+
+	return repo.SetConfig(config)
+}
diff --git a/config/set_test.go b/config/set_test.go
new file mode 100644
index 0000000..450e6ee
--- /dev/null
+++ b/config/set_test.go
@@ -0,0 +1,32 @@
+package config
+
+import (
+	"github.com/go-git/go-git/v5"
+	"github.com/stretchr/testify/assert"
+	"os"
+	"testing"
+)
+
+func TestSet(t *testing.T) {
+	assert := assert.New(t)
+
+	dir, err := os.MkdirTemp("", "bazel-git-config-set-dir-")
+	assert.Nil(err)
+	defer os.RemoveAll(dir)
+
+	repo, err := git.PlainInitWithOptions(dir, &git.PlainInitOptions{
+		Bare: true,
+	})
+	assert.Nil(err)
+
+	err = Set(SetOptions{
+		GitDir: dir,
+		Name:   "user.name",
+		Value:  "Jango Fett",
+	})
+	assert.Nil(err)
+
+	config, err := repo.Config()
+	assert.Nil(err)
+	assert.Equal(config.User.Name, "Jango Fett")
+}
-- 
GitLab