test: add unit tests for rewriter

src/internal/rewrite/rewriter_test.go

@@ -0,0 +1,90 @@
+package rewrite
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"net"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/sunbk201/ua3f/internal/config"
+)
+
+type mockConn struct {
+	io.Reader
+	io.Writer
+}
+
+func (m *mockConn) Close() error                       { return nil }
+func (m *mockConn) LocalAddr() net.Addr                { return &net.IPAddr{} }
+func (m *mockConn) RemoteAddr() net.Addr               { return &net.IPAddr{} }
+func (m *mockConn) SetDeadline(t time.Time) error      { return nil }
+func (m *mockConn) SetReadDeadline(t time.Time) error  { return nil }
+func (m *mockConn) SetWriteDeadline(t time.Time) error { return nil }
+
+func newTestRewriter(t *testing.T) *Rewriter {
+	cfg := &config.Config{
+		UAPattern:            "TestUA",
+		PayloadUA:            "MockUA/1.0",
+		EnablePartialReplace: false,
+	}
+	rewriter, err := New(cfg)
+	assert.NoError(t, err)
+	return rewriter
+}
+
+func TestNewRewriter(t *testing.T) {
+	cfg := &config.Config{
+		UAPattern:            "TestUA",
+		PayloadUA:            "FFF0",
+		EnablePartialReplace: false,
+	}
+	rewriter, err := New(cfg)
+	assert.NoError(t, err)
+	assert.Equal(t, cfg.PayloadUA, rewriter.payloadUA)
+	assert.Equal(t, cfg.UAPattern, rewriter.pattern)
+	assert.Equal(t, cfg.EnablePartialReplace, rewriter.enablePartialReplace)
+	assert.NotNil(t, rewriter.uaRegex)
+	assert.NotNil(t, rewriter.cache)
+}
+
+func TestIsHTTP(t *testing.T) {
+	r := newTestRewriter(t)
+
+	tests := []struct {
+		name     string
+		input    string
+		expected bool
+	}{
+		{"HTTP Get", "GET / HTTP/1.1\r\n", true},
+		{"HTTP Post", "POST /test HTTP/1.1\r\n", true},
+		{"HTTP Connect", "CONNECT example.com:443 HTTP/1.1\r\n", true},
+		{"Not HTTP", "HELLO WORLD\r\n", false},
+		{"Not HTTP", "SSH-2.0-OpenSSH_8.4\r\n", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			reader := bufio.NewReader(strings.NewReader(tt.input))
+			isHTTP, _ := r.isHTTP(reader)
+			assert.Equal(t, tt.expected, isHTTP)
+		})
+	}
+}
+
+func TestProxyHTTPOrRaw_HTTPRewrite(t *testing.T) {
+	r := newTestRewriter(t)
+
+	reqStr := "GET / HTTP/1.1\r\nHost: example.com\r\nUser-Agent: MyTestUA\r\n\r\n"
+	src := &mockConn{Reader: strings.NewReader(reqStr), Writer: &bytes.Buffer{}}
+	dstBuf := &bytes.Buffer{}
+	dst := &mockConn{Reader: nil, Writer: dstBuf}
+
+	r.ProxyHTTPOrRaw(dst, src, "example.com:80")
+
+	out := dstBuf.String()
+	assert.Contains(t, out, "User-Agent: MockUA/1.0")
+}