feat: add option to configure number of context lines in diffs (#22)

- Add a `diff_unified` option to generate diffs with a specific number of lines of context.
- Modify `git.New()` to accept options to configure the `diff_unified` value.
- Add a new file `git/options.go` that defines an `Option` interface and a `WithDiffUnified` function to set the `diff_unified` value.

fix #21 
fix #6

Author: appleboy

cmd/commit.go

@@ -19,13 +19,14 @@ var (
 	commitLang  string
 	commitModel string
 
-	// disbale auot commit in Hook mode
-	preview bool
+	preview     bool
+	diffUnified int
 )
 
 func init() {
 	commitCmd.PersistentFlags().StringP("file", "f", ".git/COMMIT_EDITMSG", "commit message file")
 	commitCmd.PersistentFlags().BoolVar(&preview, "preview", false, "preview commit message")
+	commitCmd.PersistentFlags().IntVar(&diffUnified, "diff_unified", 3, "generate diffs with <n> lines of context, default is 3")
 	commitCmd.PersistentFlags().StringVar(&commitModel, "model", "gpt-3.5-turbo", "select openai model")
 	commitCmd.PersistentFlags().StringVar(&commitLang, "lang", "en", "summarizing language uses English by default")
 	_ = viper.BindPFlag("output.file", commitCmd.PersistentFlags().Lookup("file"))
@@ -42,7 +43,13 @@ var commitCmd = &cobra.Command{
 			return errors.New("To use CodeGPT, you must have git on your PATH")
 		}
 
-		g := git.New()
+		if diffUnified != 3 {
+			viper.Set("git.diff_unified", diffUnified)
+		}
+
+		g := git.New(
+			git.WithDiffUnified(viper.GetInt("git.diff_unified")),
+		)
 		diff, err := g.DiffFiles()
 		if err != nil {
 			return err

cmd/config.go

@@ -18,11 +18,14 @@ func init() {
 	configCmd.PersistentFlags().StringP("lang", "l", "en", "summarizing language uses English by default")
 	configCmd.PersistentFlags().StringP("org_id", "o", "", "openai requesting organization")
 	configCmd.PersistentFlags().StringP("proxy", "", "", "http proxy")
+	configCmd.PersistentFlags().IntP("diff_unified", "", 3, "generate diffs with <n> lines of context, default is 3")
+
 	_ = viper.BindPFlag("openai.org_id", configCmd.PersistentFlags().Lookup("org_id"))
 	_ = viper.BindPFlag("openai.api_key", configCmd.PersistentFlags().Lookup("api_key"))
 	_ = viper.BindPFlag("openai.model", configCmd.PersistentFlags().Lookup("model"))
 	_ = viper.BindPFlag("openai.proxy", configCmd.PersistentFlags().Lookup("proxy"))
 	_ = viper.BindPFlag("output.lang", configCmd.PersistentFlags().Lookup("lang"))
+	_ = viper.BindPFlag("git.diff_unified", configCmd.PersistentFlags().Lookup("diff_unified"))
 }
 
 var configCmd = &cobra.Command{

commitlint.config.js

@@ -1 +1,6 @@
-module.exports = {extends: ['@commitlint/config-conventional']}
+module.exports = {
+  extends: ['@commitlint/config-conventional'],
+  rules: {
+    'body-max-line-length': [0, 'always', 'Infinity'],
+  },
+};

git/git.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"os/exec"
 	"path"
+	"strconv"
 	"strings"
 
 	"github.com/appleboy/CodeGPT/util"
@@ -20,7 +21,10 @@ var excludeFromDiff = []string{
 	"go.mod",
 }
 
-type Command struct{}
+type Command struct {
+	// Generate diffs with <n> lines of context instead of the usual three
+	diffUnified int
+}
 
 func (c *Command) excludeFiles() []string {
 	newFileLists := []string{}
@@ -52,7 +56,7 @@ func (c *Command) diffFiles() *exec.Cmd {
 		"--staged",
 		"--ignore-all-space",
 		"--diff-algorithm=minimal",
-		"--function-context",
+		"--unified=" + strconv.Itoa(c.diffUnified),
 	}
 
 	args = append(args, c.excludeFiles()...)
@@ -151,6 +155,16 @@ func (c *Command) UninstallHook() error {
 	return os.Remove(target)
 }
 
-func New() *Command {
-	return &Command{}
+func New(opts ...Option) *Command {
+	cfg := &config{}
+
+	// Loop through each option
+	for _, o := range opts {
+		// Call the option giving the instantiated
+		o.apply(cfg)
+	}
+
+	return &Command{
+		diffUnified: cfg.diffUnified,
+	}
 }

git/options.go

@@ -0,0 +1,30 @@
+package git
+
+// Option is an interface that specifies instrumentation configuration options.
+type Option interface {
+	apply(*config)
+}
+
+// optionFunc is a type of function that can be used to implement the Option interface.
+// It takes a pointer to a config struct and modifies it.
+type optionFunc func(*config)
+
+// Ensure that optionFunc satisfies the Option interface.
+var _ Option = (*optionFunc)(nil)
+
+// The apply method of optionFunc type is implemented here to modify the config struct based on the function passed.
+func (o optionFunc) apply(c *config) {
+	o(c)
+}
+
+// WithDiffUnified is a function that generate diffs with <n> lines of context instead of the usual three.
+func WithDiffUnified(val int) Option {
+	return optionFunc(func(c *config) {
+		c.diffUnified = val
+	})
+}
+
+// config is a struct that stores configuration options for the instrumentation.
+type config struct {
+	diffUnified int
+}