Implemented API endpoint to sign arbitrary data

internal/client/signer/local.go

@@ -0,0 +1,34 @@
+package signer
+
+import (
+	"context"
+	"io"
+	"strings"
+)
+
+type Signer interface {
+	Sign(data io.Reader) ([]byte, error)
+	GetPublicKey(format string) ([]byte, error)
+}
+
+type LocalSigner struct {
+	Signer
+}
+
+func (s *LocalSigner) Sign(ctx context.Context, data string) (string, error) {
+	signed, err := s.Signer.Sign(strings.NewReader(data))
+	if err != nil {
+		return "", err
+	}
+
+	return string(signed), nil
+}
+
+func (s *LocalSigner) GetPublicKey(ctx context.Context, format string) (string, error) {
+	publicKey, err := s.Signer.GetPublicKey(format)
+	if err != nil {
+		return "", err
+	}
+
+	return string(publicKey), nil
+}

internal/client/signer/local_test.go

@@ -0,0 +1,104 @@
+package signer
+
+import (
+	"context"
+	"errors"
+	"io"
+	"testing"
+
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/suite"
+)
+
+type SignerMock struct {
+	mock.Mock
+}
+
+func (m *SignerMock) Sign(data io.Reader) ([]byte, error) {
+	args := m.Called(data)
+	var result []byte
+	if casted, ok := args.Get(0).([]byte); ok {
+		result = casted
+	}
+
+	return result, args.Error(1)
+}
+
+func (m *SignerMock) GetPublicKey(format string) ([]byte, error) {
+	args := m.Called(format)
+	var result []byte
+	if casted, ok := args.Get(0).([]byte); ok {
+		result = casted
+	}
+
+	return result, args.Error(1)
+}
+
+type LocalSignerServiceTestSuite struct {
+	suite.Suite
+
+	Service *LocalSigner
+
+	Signer *SignerMock
+}
+
+func (t *LocalSignerServiceTestSuite) SetupSubTest() {
+	t.Signer = &SignerMock{}
+
+	t.Service = &LocalSigner{
+		Signer: t.Signer,
+	}
+}
+
+func (t *LocalSignerServiceTestSuite) TearDownSubTest() {
+	t.Signer.AssertExpectations(t.T())
+}
+
+func (t *LocalSignerServiceTestSuite) TestSign() {
+	t.Run("successfully sign", func() {
+		signature := []byte("mock signature")
+		t.Signer.On("Sign", mock.Anything).Return(signature, nil).Run(func(args mock.Arguments) {
+			r, _ := io.ReadAll(args.Get(0).(io.Reader))
+			t.Equal([]byte("mock body to sign"), r)
+		})
+
+		result, err := t.Service.Sign(context.Background(), "mock body to sign")
+		t.NoError(err)
+		t.Equal(string(signature), result)
+	})
+
+	t.Run("handle error during sign", func() {
+		expectedErr := errors.New("mock error")
+		t.Signer.On("Sign", mock.Anything).Return(nil, expectedErr)
+
+		result, err := t.Service.Sign(context.Background(), "mock body to sign")
+		t.Error(err)
+		t.Same(expectedErr, err)
+		t.Empty(result)
+	})
+}
+
+func (t *LocalSignerServiceTestSuite) TestGetPublicKey() {
+	t.Run("successfully get", func() {
+		publicKey := []byte("mock public key")
+		t.Signer.On("GetPublicKey", "pem").Return(publicKey, nil)
+
+		result, err := t.Service.GetPublicKey(context.Background(), "pem")
+		t.NoError(err)
+		t.Equal(string(publicKey), result)
+	})
+
+	t.Run("handle error", func() {
+		expectedErr := errors.New("mock error")
+		t.Signer.On("GetPublicKey", "pem").Return(nil, expectedErr)
+
+		result, err := t.Service.GetPublicKey(context.Background(), "pem")
+		t.Error(err)
+		t.Same(expectedErr, err)
+		t.Empty(result)
+	})
+}
+
+func TestLocalSignerService(t *testing.T) {
+	suite.Run(t, new(LocalSignerServiceTestSuite))
+}