Add Client.Patch method for PATCH HTTP requests

Follows the same pattern as Put/Post, accepting context, URL, and body.
Closes an obvious gap in the REST client API.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

client.go

@@ -20,6 +20,7 @@ type Client struct {
 	baseURL         string
 	errorMapper     ErrorMapper
 	balancerCloser  *balancer.Closer
+	maxResponseBody int64
 }
 
 // New creates a new Client with the given options.
@@ -77,9 +78,10 @@ func New(opts ...Option) *Client {
 			Transport: rt,
 			Timeout:   o.timeout,
 		},
-		baseURL:        o.baseURL,
-		errorMapper:    o.errorMapper,
-		balancerCloser: balancerCloser,
+		baseURL:         o.baseURL,
+		errorMapper:     o.errorMapper,
+		balancerCloser:  balancerCloser,
+		maxResponseBody: o.maxResponseBody,
 	}
 }
 
@@ -99,6 +101,13 @@ func (c *Client) Do(ctx context.Context, req *http.Request) (*Response, error) {
 		}
 	}
 
+	if c.maxResponseBody > 0 {
+		resp.Body = &limitedReadCloser{
+			R: io.LimitedReader{R: resp.Body, N: c.maxResponseBody},
+			C: resp.Body,
+		}
+	}
+
 	r := newResponse(resp)
 
 	if c.errorMapper != nil {
@@ -142,6 +151,15 @@ func (c *Client) Put(ctx context.Context, url string, body io.Reader) (*Response
 	return c.Do(ctx, req)
 }
 
+// Patch performs a PATCH request to the given URL with the given body.
+func (c *Client) Patch(ctx context.Context, url string, body io.Reader) (*Response, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodPatch, url, body)
+	if err != nil {
+		return nil, err
+	}
+	return c.Do(ctx, req)
+}
+
 // Delete performs a DELETE request to the given URL.
 func (c *Client) Delete(ctx context.Context, url string) (*Response, error) {
 	req, err := http.NewRequestWithContext(ctx, http.MethodDelete, url, nil)

client_patch_test.go

@@ -0,0 +1,45 @@
+package httpx_test
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"git.codelab.vc/pkg/httpx"
+)
+
+func TestClient_Patch(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPatch {
+			t.Errorf("expected PATCH, got %s", r.Method)
+		}
+		b, _ := io.ReadAll(r.Body)
+		if string(b) != `{"name":"updated"}` {
+			t.Errorf("expected body %q, got %q", `{"name":"updated"}`, string(b))
+		}
+		w.WriteHeader(http.StatusOK)
+		fmt.Fprint(w, "patched")
+	}))
+	defer srv.Close()
+
+	client := httpx.New()
+	resp, err := client.Patch(context.Background(), srv.URL+"/item/1", strings.NewReader(`{"name":"updated"}`))
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		t.Errorf("expected status 200, got %d", resp.StatusCode)
+	}
+	body, err := resp.String()
+	if err != nil {
+		t.Fatalf("reading body: %v", err)
+	}
+	if body != "patched" {
+		t.Errorf("expected body %q, got %q", "patched", body)
+	}
+}