Add idempotent object deletion

internal/adapters/storage/s3_backend.go

@@ -23,6 +23,7 @@ type s3API interface {
 	ListObjectsV2(ctx context.Context, params *s3.ListObjectsV2Input, optFns ...func(*s3.Options)) (*s3.ListObjectsV2Output, error)
 	GetObject(ctx context.Context, params *s3.GetObjectInput, optFns ...func(*s3.Options)) (*s3.GetObjectOutput, error)
 	PutObject(ctx context.Context, params *s3.PutObjectInput, optFns ...func(*s3.Options)) (*s3.PutObjectOutput, error)
+	DeleteObject(ctx context.Context, params *s3.DeleteObjectInput, optFns ...func(*s3.Options)) (*s3.DeleteObjectOutput, error)
 	HeadObject(ctx context.Context, params *s3.HeadObjectInput, optFns ...func(*s3.Options)) (*s3.HeadObjectOutput, error)
 }
 
@@ -300,6 +301,25 @@ func (b *S3Backend) uploadReader(ctx context.Context, source io.Reader, key stri
 	return info, nil
 }
 
+// Delete removes one object. S3 deletion is idempotent when the key is absent.
+func (b *S3Backend) Delete(ctx context.Context, key string) error {
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+	normalizedKey := normalizeObjectKey(key)
+	if normalizedKey == "" {
+		return fmt.Errorf("delete object: key is required")
+	}
+	_, err := b.client.DeleteObject(ctx, &s3.DeleteObjectInput{
+		Bucket: &b.bucket,
+		Key:    &normalizedKey,
+	})
+	if err != nil {
+		return fmt.Errorf("delete object %q: %w", normalizedKey, err)
+	}
+	return nil
+}
+
 // Exists checks whether one object key exists.
 func (b *S3Backend) Exists(ctx context.Context, key string) (bool, error) {
 	normalizedKey := normalizeObjectKey(key)