Add better warnings for missing timeAttribute property

src/common/models/data-cube/data-cube.mocha.ts

@@ -17,6 +17,7 @@
 
 import { expect, use } from "chai";
 import { $, AttributeInfo } from "plywood";
+import { SinonSpy, spy } from "sinon";
 import equivalent from "../../../client/utils/test-utils/equivalent";
 import { deduceAttributes } from "../../utils/external/datacube-to-external";
 import { Cluster } from "../cluster/cluster";
@@ -724,6 +725,28 @@ describe("DataCube", () => {
         formula: "$__time"
       };
 
+      describe("timeAttribute property warnings", () => {
+        let consoleWarnSpy: SinonSpy;
+
+        beforeEach(() => {
+          consoleWarnSpy = spy(console, "warn");
+        });
+
+        afterEach(() => {
+          consoleWarnSpy.restore();
+        });
+
+        it("should warn if timeAttribute is missing", () => {
+          fromConfig({ ...baseCube }, druidCluster);
+          expect(consoleWarnSpy.args[0][0]).to.be.equal("DataCube \"wiki\" should have property timeAttribute. Setting timeAttribute to default value \"__time\"");
+        });
+
+        it("should warn if timeAttribute has different value than \"__time\"", () => {
+          fromConfig({ ...baseCube, timeAttribute: "foobar" }, druidCluster);
+          expect(consoleWarnSpy.args[0][0]).to.be.equal('timeAttribute in DataCube "wiki" should have value "__time" because it is required by Druid. Overriding timeAttribute to "__time"');
+        });
+      });
+
       it("should add timeAttribute", () => {
         const cube = fromConfig({ ...baseCube, dimensions: [timeDimensionJS] }, druidCluster);
         expect(cube.timeAttribute).to.be.equivalent($("__time"));

src/common/models/data-cube/data-cube.ts

@@ -281,7 +281,10 @@ function readAttributes(config: DataCubeJS): Pick<DataCube, "attributes" | "attr
 function readTimeAttribute(config: DataCubeJS, cluster: Cluster | undefined, dimensions: Dimensions): { dimensions: Dimensions, timeAttribute: RefExpression } {
   const isFromDruidCluster = config.clusterName !== "native" && cluster.type === "druid";
   if (isFromDruidCluster) {
-    if (config.timeAttribute !== "__time") {
+    if (!isTruthy(config.timeAttribute)) {
+      console.warn(`DataCube "${config.name}" should have property timeAttribute. Setting timeAttribute to default value "__time"`);
+    }
+    if (isTruthy(config.timeAttribute) && config.timeAttribute !== "__time") {
       console.warn(`timeAttribute in DataCube "${config.name}" should have value "__time" because it is required by Druid. Overriding timeAttribute to "__time"`);
     }
     const timeAttribute = $("__time");