fix: make DefaultMatcher strict

cassette/cassette.go

@@ -35,6 +35,8 @@ import (
 	"strings"
 	"sync"
 	"time"
+	"reflect"
+	"bytes"
 
 	"gopkg.in/yaml.v3"
 )
@@ -207,10 +209,98 @@ func (i *Interaction) GetHTTPResponse() (*http.Response, error) {
 // criteria.
 type MatcherFunc func(*http.Request, Request) bool
 
-// DefaultMatcher is used when a custom matcher is not defined and
-// compares only the method and of the HTTP request.
+// Similar to reflect.DeepEqual, but considers the contents of collections, so {} and nil would be
+// considered equal. works with Array, Map, Slice, or pointer to Array.
+func deepEqualContents(x, y any) bool {
+	if reflect.ValueOf(x).IsNil() {
+		if reflect.ValueOf(y).IsNil() {
+			return true
+		} else {
+			return reflect.ValueOf(y).Len() == 0
+		}
+	} else {
+		if reflect.ValueOf(y).IsNil() {
+			return reflect.ValueOf(x).Len() == 0
+		} else {
+			return reflect.DeepEqual(x, y)
+		}
+	}
+}
+
+func bodyMatches(r *http.Request, i Request) bool {
+	if r.Body != nil {
+		var buffer bytes.Buffer
+
+		if _, err := buffer.ReadFrom(r.Body); err != nil {
+			panic(fmt.Sprintf("failed to read %s %s body: %s", r.Method, r.URL.String(), err))
+		}
+
+		r.Body = io.NopCloser(bytes.NewBuffer(buffer.Bytes()))
+
+		if buffer.String() != i.Body {
+			return false
+		}
+	} else {
+		if len(i.Body) != 0 {
+			return false
+		}
+	}
+
+	return true
+}
+
+// DefaultMatcher is used when a custom matcher is not defined. It compares the whole HTTP request
+// and only matches, if everything (eg: method, url, headers, body, ) matches.
 func DefaultMatcher(r *http.Request, i Request) bool {
-	return r.Method == i.Method && r.URL.String() == i.URL
+
+	if r.Method != i.Method {
+		return false
+	}
+
+	if r.URL.String() != i.URL {
+		return false
+	}
+
+	if r.ProtoMajor != i.ProtoMajor {
+		return false
+	}
+	if r.ProtoMinor != i.ProtoMinor {
+		return false
+	}
+
+	if !deepEqualContents(r.Header, i.Headers) {
+		return false
+	}
+
+	if !bodyMatches(r, i) {
+		return false
+	}
+
+	if r.ContentLength != i.ContentLength {
+		return false
+	}
+
+	if !deepEqualContents(r.TransferEncoding, i.TransferEncoding) {
+		return false
+	}
+
+	if r.Host != i.Host {
+		return false
+	}
+
+	if !deepEqualContents(r.Trailer, i.Trailer) {
+		return false
+	}
+
+	if r.RemoteAddr != i.RemoteAddr {
+		return false
+	}
+
+	if r.RequestURI != i.RequestURI {
+		return false
+	}
+
+	return true
 }
 
 // OnRequestReplayFunc function is called when a request is being replayed.

recorder/recorder_test.go

@@ -1111,10 +1111,10 @@ func TestWithCustomMatcher(t *testing.T) {
 	rec.SetReplayableInteractions(true)
 
 	// All requests which hit the same URL and use the same method
-	// will match against the first recorded interaction.
+	// will match against the recorded interaction.
 	client = rec.GetDefaultClient()
 	url := fmt.Sprintf("%s%s", serverUrl, "/api/v1/foo") // Same URL as the test cases
-	req, err := http.NewRequest(http.MethodPost, url, strings.NewReader("any body will match"))
+	req, err := http.NewRequest(http.MethodPost, url, strings.NewReader("foo"))
 	if err != nil {
 		t.Fatal(err)
 	}