Merge pull request #473 from yoheimuta/fix-lib-lint/471

Fix library usage

Author: yoheimuta

README.md

@@ -273,11 +273,24 @@ You can also use protolint from Go code.
 See [Go Documentation](https://pkg.go.dev/github.com/yoheimuta/protolint/lib) and [lib/lint_test.go](https://github.com/yoheimuta/protolint/blob/master/lib/lint_test.go) in detail.
 
 ```go
-args := []string{"-config_path", "path/to/your_protolint.yaml", "."}
-var stdout bytes.Buffer
-var stderr bytes.Buffer
-
-err := lib.Lint(test.inputArgs, &stdout, &stderr)
+import (
+    "bytes"
+    
+    "github.com/yoheimuta/protolint/lib"
+)
+
+func main() {
+    args := []string{"-config_path", "path/to/your_protolint.yaml", "."}
+    var stdout bytes.Buffer
+    var stderr bytes.Buffer
+    
+    err := lib.Lint(args, &stdout, &stderr)
+    if err != nil {
+        // Handle error
+    }
+    
+    // Process output in stdout and stderr
+}
 ```
 
 ## Rules

internal/cmd/lint_runner.go

@@ -3,11 +3,11 @@ package cmd
 import (
 	"io"
 
+	"github.com/yoheimuta/protolint/internal/libinternal"
 	"github.com/yoheimuta/protolint/internal/osutil"
-	"github.com/yoheimuta/protolint/lib"
 )
 
-// CmdLintRunner implements the lib.LintRunner interface for cmd package
+// CmdLintRunner implements the LintRunner interface for cmd package
 type CmdLintRunner struct{}
 
 // NewCmdLintRunner creates a new CmdLintRunner
@@ -20,7 +20,7 @@ func (r *CmdLintRunner) Run(args []string, stdout, stderr io.Writer) osutil.Exit
 	return Do(args, stdout, stderr)
 }
 
-// Initialize registers the cmd lint runner with the lib package
+// Initialize registers the cmd lint runner with the internal library
 func Initialize() {
-	lib.SetLintRunner(NewCmdLintRunner())
+	libinternal.SetLintRunner(NewCmdLintRunner())
 }

internal/libinternal/lint.go

@@ -0,0 +1,55 @@
+package libinternal
+
+import (
+	"errors"
+	"io"
+
+	"github.com/yoheimuta/protolint/internal/osutil"
+)
+
+var (
+	// ErrLintFailure error is returned when there is a linting error
+	ErrLintFailure = errors.New("lint error")
+	// ErrInternalFailure error is returned when there is a parsing, internal, or runtime error.
+	ErrInternalFailure = errors.New("parsing, internal or runtime errors")
+)
+
+// LintRunner is an interface for running lint commands
+type LintRunner interface {
+	Run(args []string, stdout, stderr io.Writer) osutil.ExitCode
+}
+
+var defaultRunner LintRunner
+
+// SetLintRunner sets the runner used by the Lint function
+func SetLintRunner(runner LintRunner) {
+	defaultRunner = runner
+}
+
+// GetLintRunner returns the current lint runner
+func GetLintRunner() LintRunner {
+	return defaultRunner
+}
+
+// Lint is used to lint Protocol Buffer files with the protolint tool.
+// It takes an array of strings (args) representing command line arguments,
+// as well as two io.Writer instances (stdout and stderr) to which the output of the command should be written.
+// It returns an error in the case of a linting error (ErrLintFailure)
+// or a parsing, internal, or runtime error (ErrInternalFailure).
+// Otherwise, it returns nil on success.
+func Lint(args []string, stdout, stderr io.Writer) error {
+	if defaultRunner == nil {
+		return ErrInternalFailure
+	}
+
+	switch defaultRunner.Run(args, stdout, stderr) {
+	case osutil.ExitSuccess:
+		return nil
+
+	case osutil.ExitLintFailure:
+		return ErrLintFailure
+
+	default:
+		return ErrInternalFailure
+	}
+}

lib/lint.go

@@ -1,29 +1,30 @@
 package lib
 
 import (
-	"errors"
 	"io"
 
-	"github.com/yoheimuta/protolint/internal/osutil"
+	"github.com/yoheimuta/protolint/internal/cmd"
+	"github.com/yoheimuta/protolint/internal/libinternal"
 )
 
 var (
 	// ErrLintFailure error is returned when there is a linting error
-	ErrLintFailure = errors.New("lint error")
+	ErrLintFailure = libinternal.ErrLintFailure
 	// ErrInternalFailure error is returned when there is a parsing, internal, or runtime error.
-	ErrInternalFailure = errors.New("parsing, internal or runtime errors")
+	ErrInternalFailure = libinternal.ErrInternalFailure
 )
 
 // LintRunner is an interface for running lint commands
-type LintRunner interface {
-	Run(args []string, stdout, stderr io.Writer) osutil.ExitCode
-}
-
-var defaultRunner LintRunner
+type LintRunner = libinternal.LintRunner
 
 // SetLintRunner sets the runner used by the Lint function
 func SetLintRunner(runner LintRunner) {
-	defaultRunner = runner
+	libinternal.SetLintRunner(runner)
+}
+
+// GetLintRunner returns the current lint runner
+func GetLintRunner() LintRunner {
+	return libinternal.GetLintRunner()
 }
 
 // Lint is used to lint Protocol Buffer files with the protolint tool.
@@ -32,19 +33,15 @@ func SetLintRunner(runner LintRunner) {
 // It returns an error in the case of a linting error (ErrLintFailure)
 // or a parsing, internal, or runtime error (ErrInternalFailure).
 // Otherwise, it returns nil on success.
+//
+// Note: This function automatically initializes the default lint runner if none is set,
+// so you don't need to call cmd.Initialize() before using it.
 func Lint(args []string, stdout, stderr io.Writer) error {
-	if defaultRunner == nil {
-		return ErrInternalFailure
+	// Auto-initialize if needed
+	if libinternal.GetLintRunner() == nil {
+		cmd.Initialize()
 	}
 
-	switch defaultRunner.Run(args, stdout, stderr) {
-	case osutil.ExitSuccess:
-		return nil
-
-	case osutil.ExitLintFailure:
-		return ErrLintFailure
-
-	default:
-		return ErrInternalFailure
-	}
+	// Use the internal implementation
+	return libinternal.Lint(args, stdout, stderr)
 }

lib/lint_test.go

@@ -11,6 +11,14 @@ import (
 )
 
 func TestLint(t *testing.T) {
+	// Set the mock lint runner for testing
+	originalRunner := lib.GetLintRunner() // Save the original runner to restore later
+	lib.SetLintRunner(NewMockLintRunner())
+	defer func() {
+		// Restore the original runner after the test
+		lib.SetLintRunner(originalRunner)
+	}()
+
 	tests := []struct {
 		name            string
 		inputArgs       []string

lib/lint_test_runner.go renamed to lib/mock_lint_runner_test.go

@@ -1,11 +1,12 @@
-package lib
+package lib_test
 
 import (
 	"fmt"
 	"io"
 	"strings"
 
 	"github.com/yoheimuta/protolint/internal/osutil"
+	"github.com/yoheimuta/protolint/lib"
 )
 
 // MockLintRunner is a mock implementation of LintRunner for testing
@@ -38,7 +39,7 @@ func (r *MockLintRunner) Run(args []string, stdout, stderr io.Writer) osutil.Exi
 	return osutil.ExitSuccess
 }
 
-func init() {
-	// Set the default runner to our mock implementation
-	SetLintRunner(&MockLintRunner{})
+// NewMockLintRunner creates a new MockLintRunner
+func NewMockLintRunner() lib.LintRunner {
+	return &MockLintRunner{}
 }

mcp/tools.go

@@ -6,7 +6,7 @@ import (
 	"encoding/json"
 	"fmt"
 
-	"github.com/yoheimuta/protolint/lib"
+	"github.com/yoheimuta/protolint/internal/libinternal"
 )
 
 // Tool defines the interface for MCP tools
@@ -92,12 +92,12 @@ func (t *LintFilesTool) Execute(args json.RawMessage) (any, error) {
 	var errorBuffer bytes.Buffer
 
 	// Run lint command
-	err := lib.Lint(cmdArgs, &outputBuffer, &errorBuffer)
+	err := libinternal.Lint(cmdArgs, &outputBuffer, &errorBuffer)
 
 	// Determine exit code based on error
 	exitCode := 0
 	if err != nil {
-		if err == lib.ErrLintFailure {
+		if err == libinternal.ErrLintFailure {
 			exitCode = 1
 		} else {
 			exitCode = 2