feat(coverart): shared httpClient for provider HTTP plumbing (C1 prep)

2026-05-08 07:51:33 -04:00
parent 6d16aa2de4
commit b4edda5518
2 changed files with 419 additions and 0 deletions
@@ -0,0 +1,212 @@
+package coverart
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"sync/atomic"
+	"testing"
+	"time"
+)
+
+func TestHTTPClient_GetJSON_Success(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"name":"alice"}`))
+	}))
+	defer srv.Close()
+
+	c := newHTTPClient(httpClientOptions{Name: "test"})
+	var got struct{ Name string }
+	if err := c.getJSON(context.Background(), srv.URL, &got); err != nil {
+		t.Fatalf("unexpected err: %v", err)
+	}
+	if got.Name != "alice" {
+		t.Errorf("Name = %q, want alice", got.Name)
+	}
+}
+
+func TestHTTPClient_GetJSON_404IsNotFound(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusNotFound)
+	}))
+	defer srv.Close()
+
+	c := newHTTPClient(httpClientOptions{Name: "test"})
+	var out any
+	err := c.getJSON(context.Background(), srv.URL, &out)
+	if !errors.Is(err, ErrNotFound) {
+		t.Errorf("err = %v, want ErrNotFound", err)
+	}
+}
+
+func TestHTTPClient_GetJSON_RetryOn429ThenSuccess(t *testing.T) {
+	var calls atomic.Int32
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		n := calls.Add(1)
+		if n < 3 {
+			w.WriteHeader(http.StatusTooManyRequests)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"ok":true}`))
+	}))
+	defer srv.Close()
+
+	c := newHTTPClient(httpClientOptions{
+		Name:        "test",
+		MaxRetries:  3,
+		BaseBackoff: 1 * time.Millisecond, // tiny so the test is fast
+	})
+	var got struct{ OK bool }
+	if err := c.getJSON(context.Background(), srv.URL, &got); err != nil {
+		t.Fatalf("unexpected err: %v", err)
+	}
+	if calls.Load() != 3 {
+		t.Errorf("calls = %d, want 3", calls.Load())
+	}
+	if !got.OK {
+		t.Errorf("OK = false, want true")
+	}
+}
+
+func TestHTTPClient_GetJSON_RetryOn5xxThenExhausted(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusServiceUnavailable)
+	}))
+	defer srv.Close()
+
+	c := newHTTPClient(httpClientOptions{
+		Name:        "test",
+		MaxRetries:  2,
+		BaseBackoff: 1 * time.Millisecond,
+	})
+	var out any
+	err := c.getJSON(context.Background(), srv.URL, &out)
+	if !errors.Is(err, ErrTransient) {
+		t.Errorf("err = %v, want ErrTransient", err)
+	}
+}
+
+func TestHTTPClient_GetJSON_AuthAsTransient(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusUnauthorized)
+	}))
+	defer srv.Close()
+
+	c := newHTTPClient(httpClientOptions{
+		Name:                 "test",
+		TreatAuthAsTransient: true,
+	})
+	var out any
+	err := c.getJSON(context.Background(), srv.URL, &out)
+	if !errors.Is(err, ErrTransient) {
+		t.Errorf("err = %v, want ErrTransient", err)
+	}
+}
+
+func TestHTTPClient_GetJSON_AuthPassthroughByDefault(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusUnauthorized)
+	}))
+	defer srv.Close()
+
+	c := newHTTPClient(httpClientOptions{Name: "test"})
+	var out any
+	err := c.getJSON(context.Background(), srv.URL, &out)
+	if !errors.Is(err, ErrTransient) {
+		// 401 is non-2xx so it falls into the generic transient bucket.
+		t.Errorf("err = %v, want ErrTransient (generic non-2xx)", err)
+	}
+}
+
+func TestHTTPClient_GetJSON_MalformedBody(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		_, _ = w.Write([]byte(`not json`))
+	}))
+	defer srv.Close()
+
+	c := newHTTPClient(httpClientOptions{Name: "test"})
+	var got struct{ Name string }
+	err := c.getJSON(context.Background(), srv.URL, &got)
+	if !errors.Is(err, ErrTransient) {
+		t.Errorf("err = %v, want ErrTransient", err)
+	}
+}
+
+func TestHTTPClient_GetJSON_ContextCancel(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusServiceUnavailable)
+	}))
+	defer srv.Close()
+
+	c := newHTTPClient(httpClientOptions{
+		Name:        "test",
+		MaxRetries:  5,
+		BaseBackoff: 200 * time.Millisecond,
+	})
+	ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond)
+	defer cancel()
+	var out any
+	err := c.getJSON(ctx, srv.URL, &out)
+	if !errors.Is(err, context.DeadlineExceeded) {
+		t.Errorf("err = %v, want context.DeadlineExceeded", err)
+	}
+}
+
+func TestHTTPClient_GetImage_Success(t *testing.T) {
+	want := []byte("\x89PNG\x0d\x0a\x1a\x0a-fake-png-bytes")
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.Header().Set("Content-Type", "image/png")
+		_, _ = w.Write(want)
+	}))
+	defer srv.Close()
+
+	c := newHTTPClient(httpClientOptions{Name: "test"})
+	got, err := c.getImage(context.Background(), srv.URL)
+	if err != nil {
+		t.Fatalf("unexpected err: %v", err)
+	}
+	if string(got) != string(want) {
+		t.Errorf("body mismatch")
+	}
+}
+
+func TestHTTPClient_GetImage_404IsNotFound(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusNotFound)
+	}))
+	defer srv.Close()
+
+	c := newHTTPClient(httpClientOptions{Name: "test"})
+	_, err := c.getImage(context.Background(), srv.URL)
+	if !errors.Is(err, ErrNotFound) {
+		t.Errorf("err = %v, want ErrNotFound", err)
+	}
+}
+
+func TestHTTPClient_RateLimit(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		_ = json.NewEncoder(w).Encode(struct{ OK bool }{true})
+	}))
+	defer srv.Close()
+
+	c := newHTTPClient(httpClientOptions{
+		Name:        "test",
+		MinInterval: 50 * time.Millisecond,
+	})
+	var out struct{ OK bool }
+	t0 := time.Now()
+	if err := c.getJSON(context.Background(), srv.URL, &out); err != nil {
+		t.Fatalf("first call: %v", err)
+	}
+	if err := c.getJSON(context.Background(), srv.URL, &out); err != nil {
+		t.Fatalf("second call: %v", err)
+	}
+	elapsed := time.Since(t0)
+	if elapsed < 50*time.Millisecond {
+		t.Errorf("elapsed %v, want >= 50ms (rate limit)", elapsed)
+	}
+}