Feature/trendline w many outputs (#12811)

* trendline check for simple q

* skip so test passes until issue resolves

* replaced wait(1000)s

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

+import {
+  restore,
+  signInAsNormalUser,
+  openOrdersTable,
+  sidebar,
+} from "__support__/cypress";
+
+describe("scenarios > question > trendline", () => {
+  before(restore);
+  beforeEach(signInAsNormalUser);
+
+  it.skip("displays trendline when there are multiple numeric outputs (for simple question) (Issue #12781)", () => {
+    // Create question: orders summarized with "Average of Subtotal" and "Sum of Total" by CreatedAt:Year
+    openOrdersTable();
+    cy.get(".Icon-notebook").click();
+    cy.findByText("Summarize").click();
+    cy.findByText("Average of ...").click();
+    cy.findByText("Subtotal").click();
+
+    cy.get(".Icon-add")
+      .last()
+      .click();
+    cy.findByText("Sum of ...").click();
+    cy.findByText("Total").click();
+
+    cy.findByText("Pick a column to group by").click();
+    cy.findByText("Created At").click();
+    cy.findByText("Created At: Month").click();
+    cy.findByText("by month").click();
+    cy.findByText("Year").click();
+
+    cy.findByText("Visualize").click();
+
+    // Check graph is there
+    cy.findByText("Visualize").should("not.exist");
+    cy.findByText("Visualization");
+    cy.get("rect");
+
+    // Change settings to trendline
+    cy.findByText("Visualization").click();
+    sidebar().within(() => {
+      cy.get(".Icon-line").click();
+    });
+    cy.findByText("Display").click();
+    cy.findByText("Trend line")
+      .parent()
+      .children()
+      .last()
+      .click();
+
+    // Check graph is still there
+    cy.get("rect");
+
+    // Remove sum of total
+    cy.findByText("Data").click();
+    sidebar().within(() => {
+      cy.get(".Icon-close")
+        .last()
+        .click();
+      cy.findByText("Done").click();
+    });
+
+    // Graph should still exist
+    cy.findByPlaceholderText("Created At").should("not.exist");
+    cy.get("rect");
+  });
+});