#155 refactor and synchronise writing to CodeOcean. (#174)

* #155 refactor and synchronise writing to CodeOcean.

* Reduce complexity of input parsing.

* Update typo in internal/api/ws/codeocean_writer.go

Co-authored-by: Sebastian Serth <MrSerth@users.noreply.github.com>

internal/api/ws/codeocean_writer_test.go

@@ -0,0 +1,100 @@
+package ws
+
+import (
+	"context"
+	"encoding/json"
+	"github.com/gorilla/websocket"
+	"github.com/openHPI/poseidon/internal/runner"
+	"github.com/openHPI/poseidon/pkg/dto"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+func TestRawToCodeOceanWriter(t *testing.T) {
+	connectionMock, message := buildConnectionMock(t)
+	proxyCtx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	output := NewCodeOceanOutputWriter(connectionMock, proxyCtx)
+	<-message // start message
+
+	t.Run("StdOut", func(t *testing.T) {
+		testMessage := "testStdOut"
+		_, err := output.StdOut().Write([]byte(testMessage))
+		require.NoError(t, err)
+
+		expected, err := json.Marshal(struct {
+			Type string `json:"type"`
+			Data string `json:"data"`
+		}{string(dto.WebSocketOutputStdout), testMessage})
+		require.NoError(t, err)
+
+		assert.Equal(t, expected, <-message)
+	})
+
+	t.Run("StdErr", func(t *testing.T) {
+		testMessage := "testStdErr"
+		_, err := output.StdErr().Write([]byte(testMessage))
+		require.NoError(t, err)
+
+		expected, err := json.Marshal(struct {
+			Type string `json:"type"`
+			Data string `json:"data"`
+		}{string(dto.WebSocketOutputStderr), testMessage})
+		require.NoError(t, err)
+
+		assert.Equal(t, expected, <-message)
+	})
+}
+
+type sendExitInfoTestCase struct {
+	name    string
+	info    *runner.ExitInfo
+	message dto.WebSocketMessage
+}
+
+func TestCodeOceanOutputWriter_SendExitInfo(t *testing.T) {
+	testCases := []sendExitInfoTestCase{
+		{"Timeout", &runner.ExitInfo{Err: runner.ErrorRunnerInactivityTimeout},
+			dto.WebSocketMessage{Type: dto.WebSocketMetaTimeout}},
+		{"Error", &runner.ExitInfo{Err: websocket.ErrCloseSent},
+			dto.WebSocketMessage{Type: dto.WebSocketOutputError, Data: "Error executing the request"}},
+		{"Exit", &runner.ExitInfo{Code: 21},
+			dto.WebSocketMessage{Type: dto.WebSocketExit, ExitCode: 21}},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.name, func(t *testing.T) {
+			connectionMock, message := buildConnectionMock(t)
+			proxyCtx, cancel := context.WithCancel(context.Background())
+			defer cancel()
+			output := NewCodeOceanOutputWriter(connectionMock, proxyCtx)
+			<-message // start message
+
+			output.SendExitInfo(test.info)
+			expected, err := json.Marshal(test.message)
+			require.NoError(t, err)
+
+			msg := <-message
+			assert.Equal(t, expected, msg)
+		})
+	}
+}
+
+func buildConnectionMock(t *testing.T) (conn *ConnectionMock, messages chan []byte) {
+	t.Helper()
+	message := make(chan []byte)
+	connectionMock := &ConnectionMock{}
+	connectionMock.On("WriteMessage", mock.AnythingOfType("int"), mock.AnythingOfType("[]uint8")).
+		Run(func(args mock.Arguments) {
+			m, ok := args.Get(1).([]byte)
+			require.True(t, ok)
+			message <- m
+		}).
+		Return(nil)
+	connectionMock.On("CloseHandler").Return(nil)
+	connectionMock.On("SetCloseHandler", mock.Anything).Return()
+	connectionMock.On("Close").Return()
+	return connectionMock, message
+}