REST API: fix and test HEAD /v1/pems

pkg/rest/allpems_handler_test.go

@@ -281,14 +281,34 @@ func TestAllPems(t *testing.T) {
 	if !barFound {
 		t.Errorf("GET /v1/pems did not return bar: %#v", allInfo)
 	}
-	if rr.Header().Get("Content-Length") != strconv.Itoa(rr.Body.Len()) {
-		t.Errorf("GET /v1/pems Content-Length: got %s want %d",
-			rr.Header().Get("Content-Length"), rr.Body.Len())
+	bodyLen := strconv.Itoa(rr.Body.Len())
+	if rr.Header().Get("Content-Length") != bodyLen {
+		t.Errorf("GET /v1/pems Content-Length: got %s want %s",
+			rr.Header().Get("Content-Length"), bodyLen)
 	}
 	if rr.Header().Get("Content-Type") != jsonContentType {
 		t.Errorf("GET /v1/pems Content-Type: got %s want %s",
 			rr.Header().Get("Content-Type"), jsonContentType)
 	}
+
+	req = httptest.NewRequest(http.MethodHead, "/v1/pems", nil)
+	rr = httptest.NewRecorder()
+	hndlr.ServeHTTP(rr, req)
+	if rr.Code != http.StatusOK {
+		t.Errorf("HEAD /v1/pems status: got %d want %d", rr.Code,
+			http.StatusOK)
+	}
+	if rr.Body.Len() != 0 {
+		t.Errorf("HEAD /v1/pems body len: got %d want 0", rr.Body.Len())
+	}
+	if rr.Header().Get("Content-Length") != bodyLen {
+		t.Errorf("HEAD /v1/pems Content-Length: got %s want %s",
+			rr.Header().Get("Content-Length"), bodyLen)
+	}
+	if rr.Header().Get("Content-Type") != jsonContentType {
+		t.Errorf("HEAD /v1/pems Content-Type: got %s want %s",
+			rr.Header().Get("Content-Type"), jsonContentType)
+	}
 }
 
 func TestAllPems405(t *testing.T) {

pkg/rest/handlers.go

@@ -266,10 +266,15 @@ func (h *pemsHndlr) allPems(
 	// XXX LastModified and ETag
 	resp.Header().Set("Content-Type", jsonContentType)
 	resp.Header().Set("Content-Length", strconv.Itoa(len(jsonBytes)))
-	n, err := resp.Write(jsonBytes)
-	if err != nil {
-		h.log.Errorf("%s %s: cannot write body: %v", req.Method,
-			req.RequestURI, err)
+	n := 0
+	if req.Method == http.MethodGet {
+		n, err = resp.Write(jsonBytes)
+		if err != nil {
+			h.log.Errorf("%s %s: cannot write body: %v", req.Method,
+				req.RequestURI, err)
+		}
+	} else {
+		resp.WriteHeader(http.StatusOK)
 	}
 	reqLog(h.log, req, now, http.StatusOK, n)
 }