feat: add response mutator option to config and update .gitignore to …

…exclude aide files

.gitignore

@@ -18,3 +18,4 @@
 # vendor/
 
 .DS_Store
+.aider*

client.go

@@ -12,6 +12,7 @@ type config struct {
 	namingScheme     NamingScheme
 	requestSanitizer RequestSanitizer
 	requestValidator RequestValidator
+	responseMutator  ResponseMutator
 	parentHTTPClient *http.Client
 }
 
@@ -50,6 +51,13 @@ func WithRequestValidator(v RequestValidator) Option {
 	}
 }
 
+// WithResponseMutator allows user to set the response mutator.
+func WithResponseMutator(m ResponseMutator) Option {
+	return func(cfg *config) {
+		cfg.responseMutator = m
+	}
+}
+
 // returns caller directory, assuming the caller is 2 levels up
 func callerDir() string {
 	_, filePath, _, _ := runtime.Caller(3)

response_mutator.go

@@ -0,0 +1,61 @@
+package hypert
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+)
+
+// ResponseMutator is an interface for types that can modify HTTP responses.
+type ResponseMutator interface {
+	MutateResponse(resp *http.Response) (*http.Response, error)
+}
+
+// JSONResponseMutator is a ResponseMutator that modifies JSON responses.
+type JSONResponseMutator[T any] func(T) (T, error)
+
+// Ensure JSONResponseMutator implements ResponseMutator
+var _ ResponseMutator = JSONResponseMutator[any](nil)
+
+// MutateResponse implements the ResponseMutator interface for JSONResponseMutator.
+func (m JSONResponseMutator[T]) MutateResponse(resp *http.Response) (mutatedResp *http.Response, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = fmt.Errorf("panic in JSONResponseMutator: %v", r)
+		}
+	}()
+
+	if resp.Header.Get("Content-Type") != "application/json" {
+		return resp, nil
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("read response body: %w", err)
+	}
+	defer resp.Body.Close()
+
+	var data T
+	if err := json.Unmarshal(body, &data); err != nil {
+		return nil, fmt.Errorf("unmarshal JSON: %w", err)
+	}
+
+	mutatedData, err := m(data)
+	if err != nil {
+		return nil, fmt.Errorf("mutate JSON: %w", err)
+	}
+
+	mutatedBody, err := json.Marshal(mutatedData)
+	if err != nil {
+		return nil, fmt.Errorf("marshal mutated JSON: %w", err)
+	}
+
+	resp.Body = io.NopCloser(bytes.NewReader(mutatedBody))
+	resp.ContentLength = int64(len(mutatedBody))
+	resp.Header.Set("Content-Length", strconv.Itoa(len(mutatedBody)))
+
+	return resp, nil
+}