Wrap package errors.

Author: s-dwinter

internal/client/aws.go

@@ -85,7 +85,7 @@ func (c awsClient) GetValues(ctx context.Context, ignoreNotFound bool) (values.V
 			if ignoreNotFound && errors.As(err, &notFoundErr) {
 				continue
 			}
-			return nil, err
+			return nil, gettingValueError(v.Name, err)
 		}
 
 		if err := values.SetValue(v, output.Parameter.Value); err != nil {
@@ -103,7 +103,7 @@ func (c awsClient) GetValues(ctx context.Context, ignoreNotFound bool) (values.V
 			if ignoreNotFound && errors.As(err, &notFoundErr) {
 				continue
 			}
-			return nil, err
+			return nil, gettingValueError(v.Name, err)
 		}
 
 		if err := values.SetValue(v, output.SecretString); err != nil {

internal/client/cache/cache.go

@@ -28,6 +28,7 @@ import (
 
 var (
 	ErrInvalidCacheType = errors.New("invalid cache type")
+	ErrCacheProcessing  = errors.New("cache processing error")
 )
 
 type Cache interface {
@@ -58,3 +59,11 @@ func New(cfg config.CacheConfig, options ...Option) (Cache, error) {
 func keyToHex(key string) string {
 	return hex.EncodeToString([]byte(key))
 }
+
+func cacheProcessingError(msg string, err error) error {
+	if err != nil {
+		return fmt.Errorf("%w: %s: %w", ErrCacheProcessing, msg, err)
+	}
+
+	return fmt.Errorf("%w: %s", ErrCacheProcessing, msg)
+}

internal/client/cache/file.go

@@ -21,7 +21,6 @@ import (
 	"crypto/aes"
 	"crypto/cipher"
 	"crypto/rand"
-	"errors"
 	"io"
 	"os"
 	"path/filepath"
@@ -66,7 +65,7 @@ func newFileCache(cfg config.FileCacheConfig, expireDuration time.Duration, opti
 
 	// create cache directory
 	if err := os.MkdirAll(fc.cachePath, 0777); err != nil {
-		return nil, err
+		return nil, cacheProcessingError("failed to create cache directory", err)
 	}
 
 	// read or create key
@@ -77,7 +76,7 @@ func newFileCache(cfg config.FileCacheConfig, expireDuration time.Duration, opti
 
 	fc.cipherBlock, err = aes.NewCipher(key)
 	if err != nil {
-		return nil, err
+		return nil, cacheProcessingError("failed to create cipher block", err)
 	}
 
 	return fc, nil
@@ -145,7 +144,7 @@ func (f *fileCache) readOrCreateKey() ([]byte, error) {
 
 		// create key file
 		if _, err := rand.Read(key); err != nil {
-			return nil, err
+			return nil, cacheProcessingError("failed to create key", err)
 		}
 		if err := f.writeToFile(keyFileName, key, false); err != nil {
 			return nil, err
@@ -178,15 +177,15 @@ func (f *fileCache) readOrCreateKey() ([]byte, error) {
 
 	// check key is not tampered
 	if err := bcrypt.CompareHashAndPassword(keyHash, key); err != nil {
-		return nil, err
+		return nil, cacheProcessingError("key is tampered", err)
 	}
 
 	return key, nil
 }
 
 func (f *fileCache) decryptCache(cipherText []byte) ([]byte, error) {
 	if len(cipherText) < aes.BlockSize {
-		return nil, errors.New("ciphertext too short")
+		return nil, cacheProcessingError("cipher text is too short", nil)
 	}
 
 	iv := cipherText[:aes.BlockSize]
@@ -202,7 +201,7 @@ func (f *fileCache) encryptCache(plainText []byte) ([]byte, error) {
 	cipherText := make([]byte, aes.BlockSize+len(plainText))
 	iv := cipherText[:aes.BlockSize]
 	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
-		return nil, err
+		return nil, cacheProcessingError("failed to create initialization vector", err)
 	}
 
 	stream := cipher.NewCFBEncrypter(f.cipherBlock, iv)
@@ -228,7 +227,7 @@ func (f fileCache) readFile(filename string, hidden bool) ([]byte, error) {
 
 	data, err := os.ReadFile(filepath.Join(f.cachePath, filename))
 	if err != nil {
-		return nil, err
+		return nil, cacheProcessingError("failed to read file", err)
 	}
 	data = data[:len(data)-1]
 
@@ -243,7 +242,7 @@ func (f fileCache) writeToFile(filename string, data []byte, hidden bool) error
 
 	file, err := os.Create(filepath.Join(f.cachePath, filename))
 	if err != nil {
-		return err
+		return cacheProcessingError("failed to create file", err)
 	}
 	defer file.Close()
 

internal/client/client.go

@@ -19,6 +19,7 @@ package client
 import (
 	"context"
 	"errors"
+	"fmt"
 
 	"github.com/dwango/yashiro/internal/values"
 	"github.com/dwango/yashiro/pkg/config"
@@ -27,6 +28,7 @@ import (
 // Define errors
 var (
 	ErrNotfoundValueConfig = errors.New("not found value config")
+	ErrGettingValue        = errors.New("failed to get value")
 )
 
 // Client is the external stores client.
@@ -52,3 +54,7 @@ func New(cfg *config.Config) (Client, error) {
 
 	return client, nil
 }
+
+func gettingValueError(name string, err error) error {
+	return fmt.Errorf("%w: name='%s': %w", ErrGettingValue, name, err)
+}

pkg/engine/engine.go

@@ -19,6 +19,8 @@ package engine
 import (
 	"bytes"
 	"context"
+	"errors"
+	"fmt"
 	"io"
 	"text/template"
 
@@ -27,6 +29,10 @@ import (
 	"github.com/dwango/yashiro/pkg/engine/encoding"
 )
 
+var (
+	ErrRendering = errors.New("failed to render")
+)
+
 // Engine is a template engine.
 type Engine interface {
 	Render(ctx context.Context, text string, dest io.Writer) error
@@ -81,12 +87,12 @@ func (e engine) Render(ctx context.Context, text string, dest io.Writer) error {
 
 func (e engine) render(text string, dest io.Writer, data any) error {
 	if _, err := e.template.Parse(text); err != nil {
-		return err
+		return fmt.Errorf("%w: %w", ErrRendering, err)
 	}
 
 	tmp := &bytes.Buffer{}
 	if err := e.template.Execute(tmp, data); err != nil {
-		return err
+		return fmt.Errorf("%w: %w", ErrRendering, err)
 	}
 
 	b, err := e.encodeAndDecoder.EncodeAndDecode(tmp.Bytes())
@@ -96,7 +102,7 @@ func (e engine) render(text string, dest io.Writer, data any) error {
 
 	_, err = io.Copy(dest, bytes.NewReader(b))
 	if err != nil {
-		return err
+		return fmt.Errorf("%w: %w", ErrRendering, err)
 	}
 
 	return nil

pkg/errors/errors.go

@@ -0,0 +1,34 @@
+/**
+ * Copyright 2024 DWANGO Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package errors
+
+import (
+	"errors"
+
+	"github.com/dwango/yashiro/internal/client/cache"
+	"github.com/dwango/yashiro/pkg/engine"
+)
+
+// IsCacheProcessingError returns true if the error is a cache processing error.
+func IsCacheProcessingError(err error) bool {
+	return errors.Is(err, cache.ErrCacheProcessing)
+}
+
+// IsRenderingError returns true if the error is a rendering error.
+func IsRenderingError(err error) bool {
+	return errors.Is(err, engine.ErrRendering)
+}

pkg/errors/errors_test.go

@@ -0,0 +1,92 @@
+/**
+ * Copyright 2024 DWANGO Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package errors
+
+import (
+	"errors"
+	"fmt"
+	"testing"
+
+	"github.com/dwango/yashiro/internal/client/cache"
+	"github.com/dwango/yashiro/pkg/engine"
+)
+
+func TestIsCacheProcessingError(t *testing.T) {
+	type args struct {
+		err error
+	}
+	tests := []struct {
+		name string
+		args args
+		want bool
+	}{
+		{
+			name: "true",
+			args: args{
+				err: fmt.Errorf("test: %w", cache.ErrCacheProcessing),
+			},
+			want: true,
+		},
+		{
+			name: "false",
+			args: args{
+				err: fmt.Errorf("test: %w", errors.New("different error")),
+			},
+			want: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := IsCacheProcessingError(tt.args.err); got != tt.want {
+				t.Errorf("IsCacheProcessingError() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestIsRenderingError(t *testing.T) {
+	type args struct {
+		err error
+	}
+	tests := []struct {
+		name string
+		args args
+		want bool
+	}{
+		{
+			name: "true",
+			args: args{
+				err: fmt.Errorf("test: %w", engine.ErrRendering),
+			},
+			want: true,
+		},
+		{
+			name: "false",
+			args: args{
+				err: fmt.Errorf("test: %w", errors.New("different error")),
+			},
+			want: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := IsRenderingError(tt.args.err); got != tt.want {
+				t.Errorf("IsRenderingError() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}