Repro for #13801: Dashboard should handle cards with null values (#13811)

The bug was fixed in #13808 .

frontend/test/metabase/scenarios/question/nulls.cy.spec.js

@@ -7,8 +7,10 @@ import {
 } from "__support__/cypress";
 
 describe("scenarios > question > null", () => {
-  before(restore);
-  beforeEach(signInAsAdmin);
+  beforeEach(() => {
+    restore();
+    signInAsAdmin();
+  });
 
   it("should display rows whose value is `null` (metabase#13571)", () => {
     withSampleDataset(({ ORDERS }) => {
@@ -127,6 +129,77 @@ describe("scenarios > question > null", () => {
     });
   });
 
+  it("dashboard should handle cards with null values (metabase#13801)", () => {
+    cy.log("**-- Create Question 1 --**");
+
+    cy.request("POST", "/api/card", {
+      name: "13801_Q1",
+      dataset_query: {
+        database: 1,
+        native: { query: "SELECT null", "template-tags": {} },
+        type: "native",
+      },
+      display: "scalar",
+      visualization_settings: {},
+    }).then(({ body: { id: Q1_ID } }) => {
+      cy.log("**-- Create Question 2 --**");
+
+      cy.request("POST", "/api/card", {
+        name: "13801_Q2",
+        dataset_query: {
+          database: 1,
+          native: { query: "SELECT 0", "template-tags": {} },
+          type: "native",
+        },
+        display: "scalar",
+        visualization_settings: {},
+      }).then(({ body: { id: Q2_ID } }) => {
+        cy.log("**-- Create Dashboard --**");
+
+        cy.request("POST", "/api/dashboard", {
+          name: "13801D",
+        }).then(({ body: { id: DASHBOARD_ID } }) => {
+          cy.log(
+            `**-- Add both previously created questions to the dashboard--**`,
+          );
+
+          [Q1_ID, Q2_ID].forEach((questionId, index) => {
+            cy.request("POST", `/api/dashboard/${DASHBOARD_ID}/cards`, {
+              cardId: questionId,
+            }).then(({ body: { id: DASHCARD_ID } }) => {
+              const CARD_SIZE_X = 6;
+
+              cy.request("PUT", `/api/dashboard/${DASHBOARD_ID}/cards`, {
+                cards: [
+                  {
+                    id: DASHCARD_ID,
+                    card_id: questionId,
+                    row: 0,
+                    col: index === 0 ? 0 : CARD_SIZE_X, // making sure the second card doesn't overlap the first one
+                    sizeX: CARD_SIZE_X,
+                    sizeY: 4,
+                    parameter_mappings: [],
+                  },
+                ],
+              });
+            });
+          });
+          cy.server();
+          cy.route("POST", "/api/card/*/query").as("cardQuery");
+
+          cy.visit(`/dashboard/${DASHBOARD_ID}`);
+          // wait for the second cardQuery to finish
+          cy.wait("@cardQuery.2");
+
+          cy.log("P0 regression in v0.37.1!");
+          cy.get(".LoadingSpinner").should("not.exist");
+          cy.findByText("13801_Q1");
+          cy.findByText("13801_Q2");
+        });
+      });
+    });
+  });
+
   describe("aggregations with null values", () => {
     beforeEach(() => {
       cy.server();