#18219 Repro: Temporal breakout fields are not formatted in export (#18436)

frontend/test/metabase/scenarios/downloads/reproductions/18219-temporal-units-not-formatted.cy.spec.js

+import { restore } from "__support__/e2e/cypress";
+import { SAMPLE_DATASET } from "__support__/e2e/cypress_sample_dataset";
+
+const xlsx = require("xlsx");
+const { ORDERS, ORDERS_ID } = SAMPLE_DATASET;
+
+const questionDetails = {
+  name: "18219",
+  query: {
+    "source-table": ORDERS_ID,
+    aggregation: [["count"]],
+    breakout: [["field", ORDERS.CREATED_AT, { "temporal-unit": "year" }]],
+  },
+};
+
+const testCases = [
+  { type: "csv", sheetName: "Sheet1" },
+  { type: "xlsx", sheetName: "Query result" },
+];
+
+describe.skip("issue 18219", () => {
+  beforeEach(() => {
+    restore();
+    cy.signInAsAdmin();
+  });
+
+  it("should format temporal units on export (metabase#18219)", () => {
+    cy.createQuestion(questionDetails).then(({ body: { id } }) => {
+      cy.intercept("POST", `/api/card/${id}/query`).as("cardQuery");
+      cy.visit(`/question/${id}`);
+
+      // Wait for `result_metadata` to load
+      cy.wait("@cardQuery");
+
+      cy.findByText("Created At: Year");
+      cy.findByText("2016");
+      cy.findByText("744");
+
+      cy.icon("download").click();
+
+      cy.wrap(testCases).each(({ type, sheetName }) => {
+        cy.log(`downloading a ${type} file`);
+        const endpoint = `/api/card/${id}/query/${type}`;
+
+        cy.request({
+          url: endpoint,
+          method: "POST",
+          encoding: "binary",
+        }).then(resp => {
+          const workbook = xlsx.read(resp.body, {
+            type: "binary",
+            raw: true,
+          });
+
+          const A1 = workbook.Sheets[sheetName]["A1"];
+          const A2 = workbook.Sheets[sheetName]["A2"];
+
+          expect(A1.v).to.eq("Created At: Year");
+
+          if (type === "csv") {
+            expect(A2.v).to.eq("2016");
+          }
+
+          if (type === "xlsx") {
+            /**
+             * Depending on how we end up solving this issue,
+             * the following assertion on the cell type might not be correct.
+             * It's very likely we'll format temporal breakouts as strings.
+             * I.e. we have to take into account Q1, Q2, etc.
+             */
+            // expect(A2.t).to.eq("n");
+
+            /**
+             * Because of the excel date format, we cannot assert on the raw value `v`.
+             * Rather, we have to do it on the parsed value `w`.
+             */
+            expect(A2.w).to.eq("2016");
+          }
+        });
+      });
+    });
+  });
+});