added real_ip and cloudflare_real_ip middlewares, fixed that some middlewares does not work properly

internal/net/http/middleware/test_utils.go

@@ -0,0 +1,125 @@
+package middleware
+
+import (
+	"bytes"
+	_ "embed"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+
+	E "github.com/yusing/go-proxy/internal/error"
+	gpHTTP "github.com/yusing/go-proxy/internal/net/http"
+)
+
+//go:embed test_data/sample_headers.json
+var testHeadersRaw []byte
+var testHeaders http.Header
+
+const testHost = "example.com"
+
+func init() {
+	tmp := map[string]string{}
+	err := json.Unmarshal(testHeadersRaw, &tmp)
+	if err != nil {
+		panic(err)
+	}
+	testHeaders = http.Header{}
+	for k, v := range tmp {
+		testHeaders.Set(k, v)
+	}
+}
+
+type requestHeaderRecorder struct {
+	parent     http.RoundTripper
+	reqHeaders http.Header
+}
+
+func (rt *requestHeaderRecorder) RoundTrip(req *http.Request) (*http.Response, error) {
+	rt.reqHeaders = req.Header
+	if rt.parent != nil {
+		return rt.parent.RoundTrip(req)
+	}
+	return &http.Response{
+		StatusCode: http.StatusOK,
+		Header:     testHeaders,
+		Body:       io.NopCloser(bytes.NewBufferString("OK")),
+		Request:    req,
+	}, nil
+}
+
+type TestResult struct {
+	RequestHeaders  http.Header
+	ResponseHeaders http.Header
+	ResponseStatus  int
+	Data            []byte
+}
+
+type testArgs struct {
+	middlewareOpt OptionsRaw
+	proxyURL      string
+	body          []byte
+	scheme        string
+}
+
+func newMiddlewareTest(middleware *Middleware, args *testArgs) (*TestResult, E.NestedError) {
+	var body io.Reader
+	var rt = new(requestHeaderRecorder)
+	var proxyURL *url.URL
+	var requestTarget string
+	var err error
+
+	if args == nil {
+		args = new(testArgs)
+	}
+
+	if args.body != nil {
+		body = bytes.NewReader(args.body)
+	}
+
+	if args.scheme == "" || args.scheme == "http" {
+		requestTarget = "http://" + testHost
+	} else if args.scheme == "https" {
+		requestTarget = "https://" + testHost
+	} else {
+		panic("typo?")
+	}
+
+	req := httptest.NewRequest(http.MethodGet, requestTarget, body)
+	w := httptest.NewRecorder()
+
+	if args.scheme == "https" && req.TLS == nil {
+		panic("bug occurred")
+	}
+
+	if args.proxyURL != "" {
+		proxyURL, err = url.Parse(args.proxyURL)
+		if err != nil {
+			return nil, E.From(err)
+		}
+		rt.parent = http.DefaultTransport
+	} else {
+		proxyURL, _ = url.Parse("https://" + testHost) // dummy url, no actual effect
+	}
+	rp := gpHTTP.NewReverseProxy(proxyURL, rt)
+	setOptErr := PatchReverseProxy(rp, map[string]OptionsRaw{
+		middleware.name: args.middlewareOpt,
+	})
+	if setOptErr != nil {
+		return nil, setOptErr
+	}
+	rp.ServeHTTP(w, req)
+	resp := w.Result()
+	defer resp.Body.Close()
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, E.From(err)
+	}
+	return &TestResult{
+		RequestHeaders:  rt.reqHeaders,
+		ResponseHeaders: resp.Header,
+		ResponseStatus:  resp.StatusCode,
+		Data:            data,
+	}, nil
+}