feat(cmd): add the init command for rslint (#250)

Author: holyfata

GUIDE.md

@@ -20,6 +20,9 @@ yarn add @rslint/core
 ### Command Line Interface
 
 ```bash
+# create the default config file
+rslint --init
+
 # use default rslint.json
 rslint
 # use custom configuration file

cmd/rslint/cmd.go

@@ -314,6 +314,7 @@ Usage:
   rslint [OPTIONS]
 
 Options:
+  --init				Initialize a default config in the current directory.
   --config PATH         Which rslint config file to use. Defaults to rslint.json.
   --format FORMAT       Output format: default | jsonline
   --fix                 Automatically fix problems
@@ -328,6 +329,7 @@ func runCMD() int {
 	flag.Usage = func() { fmt.Fprint(os.Stderr, usage) }
 
 	var (
+		init   bool
 		help   bool
 		config string
 		fix    bool
@@ -343,6 +345,7 @@ func runCMD() int {
 	)
 	flag.StringVar(&format, "format", "default", "output format")
 	flag.StringVar(&config, "config", "", "which rslint config to use")
+	flag.BoolVar(&init, "init", false, "initialize a default config in the current directory")
 	flag.BoolVar(&fix, "fix", false, "automatically fix problems")
 	flag.BoolVar(&help, "help", false, "show help")
 	flag.BoolVar(&help, "h", false, "show help")
@@ -405,6 +408,14 @@ func runCMD() int {
 	}
 	currentDirectory = tspath.NormalizePath(currentDirectory)
 
+	if init {
+		if err := rslintconfig.InitDefaultConfig(currentDirectory); err != nil {
+			fmt.Fprintf(os.Stderr, "error initializing config: %v\n", err)
+			return 1
+		}
+		return 0
+	}
+
 	fs := bundled.WrapFS(cachedvfs.From(osvfs.FS()))
 
 	// Initialize rule registry with all available rules

internal/config/config.go

@@ -1,7 +1,9 @@
 package config
 
 import (
+	"fmt"
 	"os"
+	"path/filepath"
 	"strings"
 
 	"github.com/bmatcuk/doublestar/v4"
@@ -129,6 +131,31 @@ type RuleConfig struct {
 	Options map[string]interface{} `json:"options,omitempty"` // Rule-specific options
 }
 
+const defaultJsonc = `
+[
+  {
+    // ignore files and folders for linting
+    "ignores": [],
+    "languageOptions": {
+      "parserOptions": {
+        // Rslint will lint all files included in your typescript projects defined here
+        // support lint multi packages in monorepo
+        "project": ["./tsconfig.json"]
+      }
+    },
+    // same configuration as https://typescript-eslint.io/rules/
+    "rules": {
+      "@typescript-eslint/require-await": "off",
+      "@typescript-eslint/no-unnecessary-type-assertion": "warn",
+      "@typescript-eslint/array-type": ["warn", { "default": "array-simple" }]
+    },
+    "plugins": [
+      "@typescript-eslint" // will enable all implemented @typescript-eslint rules by default
+    ]
+  }
+]
+`
+
 // IsEnabled returns true if the rule is enabled (not "off")
 func (rc *RuleConfig) IsEnabled() bool {
 	if rc == nil {
@@ -401,3 +428,21 @@ func isFileIgnoredSimple(filePath string, ignorePatterns []string) bool {
 	}
 	return false
 }
+
+// initialize a default config in the directory
+func InitDefaultConfig(directory string) error {
+	configPath := filepath.Join(directory, "rslint.jsonc")
+
+	// if the config exists
+	if _, err := os.Stat(configPath); err == nil {
+		return fmt.Errorf("rslint.json already exists in %s", directory)
+	}
+
+	// write file content
+	err := os.WriteFile(configPath, []byte(defaultJsonc), 0644)
+	if err != nil {
+		return fmt.Errorf("failed to create rslint.json: %w", err)
+	}
+
+	return nil
+}

internal/config/config_test.go

@@ -1,6 +1,9 @@
 package config
 
 import (
+	"os"
+	"path/filepath"
+	"strings"
 	"testing"
 
 	"github.com/bmatcuk/doublestar/v4"
@@ -491,3 +494,151 @@ func TestGetRulesForFileWithArrayConfig(t *testing.T) {
 		t.Error("expected rule5 to exist")
 	}
 }
+
+func TestInitDefaultConfig(t *testing.T) {
+	t.Run("create config in empty directory", func(t *testing.T) {
+		tempDir := t.TempDir()
+
+		err := InitDefaultConfig(tempDir)
+		if err != nil {
+			t.Fatalf("InitDefaultConfig failed: %v", err)
+		}
+
+		configPath := filepath.Join(tempDir, "rslint.jsonc")
+		if _, err := os.Stat(configPath); os.IsNotExist(err) {
+			t.Error("rslint.jsonc file was not created")
+		}
+
+		content, err := os.ReadFile(configPath)
+		if err != nil {
+			t.Fatalf("failed to read created config file: %v", err)
+		}
+
+		if string(content) != defaultJsonc {
+			t.Error("created config file content does not match expected default content")
+		}
+	})
+
+	t.Run("fail when config already exists", func(t *testing.T) {
+		tempDir := t.TempDir()
+		configPath := filepath.Join(tempDir, "rslint.jsonc")
+
+		err := os.WriteFile(configPath, []byte("existing content"), 0644)
+		if err != nil {
+			t.Fatalf("failed to create existing config file: %v", err)
+		}
+
+		err = InitDefaultConfig(tempDir)
+		if err == nil {
+			t.Error("expected InitDefaultConfig to fail when config already exists")
+		}
+
+		expectedErrorMsg := "rslint.json already exists in " + tempDir
+		if err.Error() != expectedErrorMsg {
+			t.Errorf("expected error message %q, got %q", expectedErrorMsg, err.Error())
+		}
+
+		content, err := os.ReadFile(configPath)
+		if err != nil {
+			t.Fatalf("failed to read config file: %v", err)
+		}
+
+		if string(content) != "existing content" {
+			t.Error("existing config file was modified")
+		}
+	})
+
+	t.Run("fail with invalid directory", func(t *testing.T) {
+		invalidDir := "/nonexistent/directory/path"
+
+		err := InitDefaultConfig(invalidDir)
+		if err == nil {
+			t.Error("expected InitDefaultConfig to fail with invalid directory")
+		}
+
+		expectedPrefix := "failed to create rslint.json:"
+		if !strings.HasPrefix(err.Error(), expectedPrefix) {
+			t.Errorf("expected error to start with %q, got %q", expectedPrefix, err.Error())
+		}
+	})
+
+	t.Run("create config with relative path", func(t *testing.T) {
+		tempDir := t.TempDir()
+
+		originalWD, err := os.Getwd()
+		if err != nil {
+			t.Fatalf("failed to get current working directory: %v", err)
+		}
+		defer func() {
+			t.Chdir(originalWD)
+		}()
+
+		t.Chdir(tempDir)
+
+		err = InitDefaultConfig(".")
+		if err != nil {
+			t.Fatalf("InitDefaultConfig with relative path failed: %v", err)
+		}
+
+		configPath := "rslint.jsonc"
+		if _, err := os.Stat(configPath); os.IsNotExist(err) {
+			t.Error("rslint.jsonc file was not created with relative path")
+		}
+	})
+
+	t.Run("create config in nested directory", func(t *testing.T) {
+		tempDir := t.TempDir()
+
+		nestedDir := filepath.Join(tempDir, "project", "config")
+		err := os.MkdirAll(nestedDir, 0755)
+		if err != nil {
+			t.Fatalf("failed to create nested directory: %v", err)
+		}
+
+		err = InitDefaultConfig(nestedDir)
+		if err != nil {
+			t.Fatalf("InitDefaultConfig in nested directory failed: %v", err)
+		}
+
+		configPath := filepath.Join(nestedDir, "rslint.jsonc")
+		if _, err := os.Stat(configPath); os.IsNotExist(err) {
+			t.Error("rslint.jsonc file was not created in nested directory")
+		}
+	})
+
+	t.Run("verify config content is valid JSON", func(t *testing.T) {
+		tempDir := t.TempDir()
+
+		err := InitDefaultConfig(tempDir)
+		if err != nil {
+			t.Fatalf("InitDefaultConfig failed: %v", err)
+		}
+
+		configPath := filepath.Join(tempDir, "rslint.jsonc")
+		content, err := os.ReadFile(configPath)
+		if err != nil {
+			t.Fatalf("failed to read config file: %v", err)
+		}
+
+		if len(content) == 0 {
+			t.Error("created config file is empty")
+		}
+
+		contentStr := string(content)
+		expectedElements := []string{
+			"ignores",
+			"languageOptions",
+			"parserOptions",
+			"project",
+			"rules",
+			"plugins",
+			"@typescript-eslint",
+		}
+
+		for _, element := range expectedElements {
+			if !strings.Contains(contentStr, element) {
+				t.Errorf("config content missing expected element: %s", element)
+			}
+		}
+	})
+}