Added func asserter

Author: oliverreid

pkg/goponent/assert_json.go

@@ -17,33 +17,58 @@ type JsonResponseAsserter[T any] struct {
 }
 
 func (j JsonResponseAsserter[T]) Assert(t *testing.T, context *Context, stepContext *Context) error {
+	actualBody, res, err := extractBody[T](t, stepContext)
+	if err != nil {
+		return err
+	}
+
+	expectedBody := j.ExpectedBody
+	if j.ExpectedBodyFunc != nil {
+		expectedBody = j.ExpectedBodyFunc(context)
+	}
+
+	AssertEqual(t, expectedBody, actualBody)
+	AssertEqual(t, j.ExpectedStatusCode, res.StatusCode)
+
+	return nil
+}
+
+var _ Asserter = JsonFuncAsserter[string]{}
+
+type JsonFuncAsserter[T any] struct {
+	ExpectedFunc       func(ctx *Context, body T)
+	ExpectedStatusCode int
+}
+
+func (j JsonFuncAsserter[T]) Assert(t *testing.T, context *Context, stepContext *Context) error {
+	actualBody, res, err := extractBody[T](t, stepContext)
+	if err != nil {
+		return err
+	}
+	j.ExpectedFunc(context, actualBody)
+	AssertEqual(t, j.ExpectedStatusCode, res.StatusCode)
+	return nil
+}
+
+func extractBody[T any](t *testing.T, stepContext *Context) (T, *http.Response, error) {
+	var actualBody T
 	res, ok := ContextGet[*http.Response](stepContext, "response")
 	if !ok {
 		t.Error("no response in context")
-		return errors.New("no response in context")
+		return actualBody, res, errors.New("no response in context")
 	}
 
 	b, err := io.ReadAll(res.Body)
 	if err != nil {
 		t.Error(err)
-		return err
+		return actualBody, res, err
 	}
 
-	var actualBody T
 	t.Logf("response body: %s", string(b))
 	err = json.Unmarshal(b, &actualBody)
 	if err != nil {
 		t.Error(err)
-		return err
+		return actualBody, res, err
 	}
-
-	expectedBody := j.ExpectedBody
-	if j.ExpectedBodyFunc != nil {
-		expectedBody = j.ExpectedBodyFunc(context)
-	}
-
-	AssertEqual(t, expectedBody, actualBody)
-	AssertEqual(t, j.ExpectedStatusCode, res.StatusCode)
-
-	return nil
+	return actualBody, res, nil
 }