Big changes

server/internal/api/images_test.go

@@ -0,0 +1,54 @@
+package api
+
+import (
+	"context"
+	"errors"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"syscall"
+	"testing"
+)
+
+func TestExpectedClientDisconnect(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/v1/images/1/primary", nil)
+	for _, err := range []error{
+		context.Canceled,
+		syscall.EPIPE,
+		syscall.ECONNRESET,
+		errors.New("write tcp: broken pipe"),
+		errors.New("client disconnected"),
+	} {
+		if !expectedClientDisconnect(req, err) {
+			t.Errorf("%q should be an expected client disconnect", err)
+		}
+	}
+	if expectedClientDisconnect(req, io.ErrUnexpectedEOF) {
+		t.Fatal("an upstream truncated image must remain a real warning")
+	}
+}
+
+func TestExpectedClientDisconnectUsesRequestContext(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	req := httptest.NewRequest(http.MethodGet, "/v1/images/1/primary", nil).WithContext(ctx)
+	if !expectedClientDisconnect(req, errors.New("opaque response writer error")) {
+		t.Fatal("a cancelled request should be treated as viewer cancellation")
+	}
+}
+
+func TestTaggedImageConditionalRequestSkipsUpstream(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/v1/images/1/primary?tag=abc123", nil)
+	req.Header.Set("If-None-Match", `"abc123"`)
+	rec := httptest.NewRecorder()
+
+	if !writeNotModifiedForTag(rec, req, "abc123") {
+		t.Fatal("matching image tag should short-circuit")
+	}
+	if rec.Code != http.StatusNotModified {
+		t.Fatalf("status = %d, want 304", rec.Code)
+	}
+	if got := rec.Header().Get("ETag"); got != `"abc123"` {
+		t.Fatalf("etag = %q", got)
+	}
+}