test: create/update UTs for engine, chunk and semaphore

Author: cx-rui-oliveira

engine/chunk/chunk_test.go

@@ -0,0 +1,157 @@
+package chunk
+
+import (
+	"bufio"
+	"bytes"
+	"github.com/stretchr/testify/require"
+	"io"
+	"strings"
+	"testing"
+)
+
+func TestGetAndPutBuf(t *testing.T) {
+	chunk := NewChunk()
+	buf, ok := chunk.GetBuf()
+	defer chunk.PutBuf(buf)
+
+	require.True(t, ok)
+	require.Equal(t, defaultSize, len(*buf))
+}
+
+func TestGetAndPutPeekBuf(t *testing.T) {
+	chunk := NewChunk()
+	data := []byte("test")
+	buf, ok := chunk.GetPeekBuf(data)
+	defer chunk.PutPeekBuf(buf)
+
+	require.True(t, ok)
+	require.Equal(t, defaultSize+defaultMaxPeekSize, buf.Cap())
+	require.Equal(t, string(data), buf.String())
+}
+
+func TestGetSize(t *testing.T) {
+	chunk := NewChunk()
+	require.Equal(t, defaultSize, chunk.GetSize())
+}
+
+func TestGetMaxPeekSize(t *testing.T) {
+	chunk := NewChunk()
+	require.Equal(t, defaultMaxPeekSize, chunk.GetMaxPeekSize())
+}
+
+func TestReadChunk(t *testing.T) {
+	// Arrange
+	type testCase struct {
+		name          string
+		reader        io.Reader
+		expected      string
+		expectedError error
+	}
+	testCases := []testCase{
+		{
+			name:          "empty",
+			reader:        strings.NewReader(""),
+			expectedError: io.EOF,
+		},
+		{
+			name:          "unsupported file type",
+			reader:        bytes.NewReader([]byte{'P', 'K', 0x03, 0x04}),
+			expectedError: ErrUnsupportedFileType,
+		},
+		{
+			name:     "successful read",
+			reader:   strings.NewReader("abc\n"),
+			expected: "abc\n",
+		},
+		{
+			name:     "successful read - peek size exceeded",
+			reader:   strings.NewReader("abc\ndef\nghi\njkl\nmno\npqr\nstu\nvwx\nyz"),
+			expected: "abc\ndef\nghi\njkl\nmno\npqr\ns",
+		},
+		{
+			name:     "successful read - multiple lines with consecutives new lines",
+			reader:   strings.NewReader("abc\ndef\n\nghi\n"),
+			expected: "abc\ndef\n\n",
+		},
+		{
+			name:     "multiple lines without consecutives new lines",
+			reader:   strings.NewReader("abc\ndef\nghi\n"),
+			expected: "abc\ndef\nghi\n",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			chunk := NewChunkWithSize(5, 20, 20)
+			reader := bufio.NewReader(tc.reader)
+
+			// Act
+			result, err := chunk.ReadChunk(reader, 0)
+			require.ErrorIs(t, err, tc.expectedError)
+
+			// Assert
+			require.Equal(t, tc.expected, result)
+		})
+	}
+}
+
+func TestReadUntilSafeBoundary(t *testing.T) {
+	// Arrange
+	testCases := []struct {
+		name     string
+		reader   io.Reader
+		expected string
+	}{
+		// Current split is fine, exit early.
+		{
+			name:     "safe original split - LF",
+			reader:   strings.NewReader("abc\n\ndefghijklmnop\n\nqrstuvwxyz"),
+			expected: "abc\n\n",
+		},
+		{
+			name:     "safe original split - CRLF",
+			reader:   strings.NewReader("a\r\n\r\nbcdefghijklmnop\n"),
+			expected: "a\r\n\r\n",
+		},
+		// Current split is bad, look for a better one.
+		{
+			name:     "safe split - LF",
+			reader:   strings.NewReader("abcdefg\nhijklmnop\n\nqrstuvwxyz"),
+			expected: "abcdefg\nhijklmnop\n\n",
+		},
+		{
+			name:     "safe split - CRLF",
+			reader:   strings.NewReader("abcdefg\r\nhijklmnop\r\n\r\nqrstuvwxyz"),
+			expected: "abcdefg\r\nhijklmnop\r\n\r\n",
+		},
+		{
+			name:     "safe split - blank line",
+			reader:   strings.NewReader("abcdefg\nhijklmnop\n\t  \t\nqrstuvwxyz"),
+			expected: "abcdefg\nhijklmnop\n\t  \t\n",
+		},
+		// Current split is bad, exhaust options.
+		{
+			name:     "no safe split",
+			reader:   strings.NewReader("abcdefg\nhijklmnopqrstuvwxyz"),
+			expected: "abcdefg\nhijklmnopqrstuvwx",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			buf := make([]byte, 5)
+			n, err := tc.reader.Read(buf)
+			require.NoError(t, err)
+
+			// Act
+			chunk := NewChunkWithSize(5, 20, 20)
+			reader := bufio.NewReader(tc.reader)
+			peekBuf := bytes.NewBuffer(buf[:n])
+			err = chunk.readUntilSafeBoundary(reader, n, peekBuf)
+			require.NoError(t, err)
+
+			// Assert
+			require.Equal(t, tc.expected, peekBuf.String())
+		})
+	}
+}