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package llm
import (
"context"
"errors"
"io"
"net/http"
"net/http/httptest"
"sync/atomic"
"testing"
"time"
)
// testPolicy returns a retry policy with deterministic, instant backoff and no
// jitter so tests are fast and reproducible.
func testPolicy(maxAttempts int) retryPolicy {
return retryPolicy{
maxAttempts: maxAttempts,
baseDelay: time.Millisecond,
maxDelay: time.Millisecond,
jitterFraction: 0,
sleep: func(ctx context.Context, d time.Duration) error { return ctx.Err() },
randFloat: func() float64 { return 0.5 },
}
}
func TestShouldRetryStatus(t *testing.T) {
cases := map[int]bool{
200: false, 201: false,
400: false, 401: false, 404: false,
429: true,
500: true, 502: true, 503: true,
}
for status, want := range cases {
if got := shouldRetryStatus(status); got != want {
t.Errorf("shouldRetryStatus(%d)=%v want %v", status, got, want)
}
}
}
func TestResilient_RetriesThenSucceeds(t *testing.T) {
var calls int32
srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if atomic.AddInt32(&calls, 1) < 3 {
w.WriteHeader(http.StatusInternalServerError)
_, _ = io.WriteString(w, "boom")
return
}
w.WriteHeader(http.StatusOK)
_, _ = io.WriteString(w, "ok")
}))
defer srv.Close()
resp, err := doJSONRequestResilient(context.Background(), srv.Client(), srv.URL, []byte("{}"), nil, "", testPolicy(3), nil)
if err != nil {
t.Fatalf("unexpected error: %v", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
t.Fatalf("status=%d want 200", resp.StatusCode)
}
if got := atomic.LoadInt32(&calls); got != 3 {
t.Fatalf("expected 3 calls, got %d", got)
}
}
func TestResilient_NoRetryOn4xx(t *testing.T) {
var calls int32
srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
atomic.AddInt32(&calls, 1)
w.WriteHeader(http.StatusBadRequest)
}))
defer srv.Close()
resp, err := doJSONRequestResilient(context.Background(), srv.Client(), srv.URL, []byte("{}"), nil, "", testPolicy(3), nil)
if err != nil {
t.Fatalf("unexpected error: %v", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusBadRequest {
t.Fatalf("status=%d want 400", resp.StatusCode)
}
if got := atomic.LoadInt32(&calls); got != 1 {
t.Fatalf("4xx must not be retried: got %d calls", got)
}
}
func TestResilient_ExhaustsRetries(t *testing.T) {
var calls int32
srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
atomic.AddInt32(&calls, 1)
w.WriteHeader(http.StatusServiceUnavailable)
}))
defer srv.Close()
_, err := doJSONRequestResilient(context.Background(), srv.Client(), srv.URL, []byte("{}"), nil, "", testPolicy(3), nil)
if err == nil {
t.Fatal("expected error after exhausting retries")
}
if got := atomic.LoadInt32(&calls); got != 3 {
t.Fatalf("expected 3 attempts, got %d", got)
}
}
func TestResilient_NetworkErrorRetries(t *testing.T) {
srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
url := srv.URL
srv.Close() // closed server: connection attempts fail at the transport layer
_, err := doJSONRequestResilient(context.Background(), http.DefaultClient, url, []byte("{}"), nil, "", testPolicy(2), nil)
if err == nil {
t.Fatal("expected network error")
}
}
func TestResilient_ContextCancelStopsRetries(t *testing.T) {
var calls int32
srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
atomic.AddInt32(&calls, 1)
w.WriteHeader(http.StatusInternalServerError)
}))
defer srv.Close()
ctx, cancel := context.WithCancel(context.Background())
// Cancel during the backoff sleep after the first failed attempt.
policy := testPolicy(5)
policy.sleep = func(c context.Context, d time.Duration) error {
cancel()
return c.Err()
}
_, err := doJSONRequestResilient(ctx, srv.Client(), srv.URL, []byte("{}"), nil, "", policy, nil)
if !errors.Is(err, context.Canceled) {
t.Fatalf("expected context.Canceled, got %v", err)
}
if got := atomic.LoadInt32(&calls); got != 1 {
t.Fatalf("expected 1 attempt before cancel, got %d", got)
}
}
func TestResilient_AlreadyCancelledContext(t *testing.T) {
srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
defer srv.Close()
ctx, cancel := context.WithCancel(context.Background())
cancel()
if _, err := doJSONRequestResilient(ctx, srv.Client(), srv.URL, []byte("{}"), nil, "", testPolicy(3), nil); !errors.Is(err, context.Canceled) {
t.Fatalf("expected context.Canceled, got %v", err)
}
}
func TestResilient_CircuitOpenRejects(t *testing.T) {
cb := newCircuitBreaker(1, time.Hour)
cb.recordFailure() // trips immediately (threshold 1)
srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
t.Fatal("server should not be reached while circuit is open")
}))
defer srv.Close()
_, err := doJSONRequestResilient(context.Background(), srv.Client(), srv.URL, []byte("{}"), nil, "", testPolicy(3), cb)
if !errors.Is(err, errCircuitOpen) {
t.Fatalf("expected errCircuitOpen, got %v", err)
}
}
func TestResilient_BreakerTripsAfterExhaustedRetries(t *testing.T) {
srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusInternalServerError)
}))
defer srv.Close()
cb := newCircuitBreaker(1, time.Hour) // a single exhausted run trips it
if _, err := doJSONRequestResilient(context.Background(), srv.Client(), srv.URL, []byte("{}"), nil, "", testPolicy(2), cb); err == nil {
t.Fatal("expected error")
}
// Next call must be rejected by the now-open breaker.
if _, err := doJSONRequestResilient(context.Background(), srv.Client(), srv.URL, []byte("{}"), nil, "", testPolicy(2), cb); !errors.Is(err, errCircuitOpen) {
t.Fatalf("expected errCircuitOpen on second call, got %v", err)
}
}
func TestBackoffFor_ExponentialCappedNoJitter(t *testing.T) {
p := retryPolicy{baseDelay: 100 * time.Millisecond, maxDelay: 400 * time.Millisecond}
want := []time.Duration{
100 * time.Millisecond,
200 * time.Millisecond,
400 * time.Millisecond,
400 * time.Millisecond, // capped
}
for i, w := range want {
if got := p.backoffFor(i); got != w {
t.Errorf("backoffFor(%d)=%s want %s", i, got, w)
}
}
}
func TestBackoffFor_JitterWithinBounds(t *testing.T) {
p := retryPolicy{
baseDelay: 100 * time.Millisecond,
maxDelay: time.Second,
jitterFraction: 0.5,
randFloat: func() float64 { return 1.0 }, // max positive jitter
}
got := p.backoffFor(0)
// 100ms + 50% = 150ms.
if got != 150*time.Millisecond {
t.Fatalf("got %s want 150ms", got)
}
p.randFloat = func() float64 { return 0.0 } // max negative jitter
if got := p.backoffFor(0); got != 50*time.Millisecond {
t.Fatalf("got %s want 50ms", got)
}
}
func TestSleepWithContext_ReturnsOnDeadline(t *testing.T) {
ctx, cancel := context.WithCancel(context.Background())
cancel()
if err := sleepWithContext(ctx, time.Hour); !errors.Is(err, context.Canceled) {
t.Fatalf("expected canceled, got %v", err)
}
// Zero delay returns immediately with ctx.Err() (nil here).
if err := sleepWithContext(context.Background(), 0); err != nil {
t.Fatalf("expected nil for zero delay, got %v", err)
}
// Positive delay elapses normally.
if err := sleepWithContext(context.Background(), time.Millisecond); err != nil {
t.Fatalf("unexpected error: %v", err)
}
}
func TestResilient_DefaultPolicyDisabledRetriesWhenSingleAttempt(t *testing.T) {
var calls int32
srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
atomic.AddInt32(&calls, 1)
w.WriteHeader(http.StatusInternalServerError)
}))
defer srv.Close()
// maxAttempts <= 1 means no retries: exactly one attempt.
if _, err := doJSONRequestResilient(context.Background(), srv.Client(), srv.URL, []byte("{}"), nil, "", testPolicy(0), nil); err == nil {
t.Fatal("expected error")
}
if got := atomic.LoadInt32(&calls); got != 1 {
t.Fatalf("expected exactly 1 attempt, got %d", got)
}
}
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