#18512 Repro: Cannot join saved questions with the same implicit/explicit grouped field (#18516)

frontend/test/metabase/scenarios/question/reproductions/18512-cannot-join-two-saved-questions-with-same-implicit-explicit-grouped-field.cy.spec.js

+import { restore, popover } from "__support__/e2e/cypress";
+import { SAMPLE_DATASET } from "__support__/e2e/cypress_sample_dataset";
+
+const { PRODUCTS, PRODUCTS_ID, REVIEWS, REVIEWS_ID } = SAMPLE_DATASET;
+
+const question1 = getQuestionDetails("18512#1", "Doohickey");
+const question2 = getQuestionDetails("18512#2", "Gizmo");
+
+describe.skip("issue 18512", () => {
+  beforeEach(() => {
+    cy.intercept("POST", "/api/dataset").as("dataset");
+
+    restore();
+    cy.signInAsAdmin();
+  });
+
+  it("should join two saved questions with the same implicit/explicit grouped field (metabase#18512)", () => {
+    cy.createQuestion(question1);
+    cy.createQuestion(question2);
+
+    cy.visit("/question/new");
+    cy.findByText("Custom question").click();
+    cy.findByText("Saved Questions").click();
+
+    cy.findByText("18512#1").click();
+    cy.icon("join_left_outer").click();
+
+    popover().within(() => {
+      cy.findByText("Sample Dataset").click();
+      cy.findByText("Saved Questions").click();
+      cy.findByText("18512#2").click();
+    });
+
+    popover()
+      .findByText("Products → Created At")
+      .click();
+    popover()
+      .findByText("Products → Created At")
+      .click();
+
+    cy.button("Visualize").click();
+
+    cy.wait("@dataset").then(({ response }) => {
+      expect(response.body.error).to.not.exist;
+    });
+
+    cy.contains("Products → Created At");
+  });
+});
+
+function getQuestionDetails(name, catFilter) {
+  return {
+    name,
+    query: {
+      "source-table": REVIEWS_ID,
+      joins: [
+        {
+          fields: "all",
+          "source-table": PRODUCTS_ID,
+          condition: [
+            "=",
+            ["field", REVIEWS.PRODUCT_ID, null],
+            ["field", PRODUCTS.ID, { "join-alias": "Products" }],
+          ],
+          alias: "Products",
+        },
+      ],
+      filter: [
+        "=",
+        ["field", PRODUCTS.CATEGORY, { "join-alias": "Products" }],
+        catFilter,
+      ],
+      aggregation: [
+        ["distinct", ["field", PRODUCTS.ID, { "join-alias": "Products" }]],
+      ],
+      breakout: [
+        [
+          "field",
+          PRODUCTS.CREATED_AT,
+          { "join-alias": "Products", "temporal-unit": "month" },
+        ],
+      ],
+    },
+  };
+}