chore: import upstream snapshot with attribution

apps/webapp/test/duplicateTaskIds.test.ts

@@ -0,0 +1,60 @@
+import { describe, it, expect } from "vitest";
+import { ServiceValidationError } from "~/v3/services/common.server";
+import { assertNoDuplicateTaskIds } from "~/v3/services/duplicateTaskIds.server";
+
+function task(partial: {
+  id: string;
+  filePath?: string;
+  exportName?: string;
+  triggerSource?: string;
+}) {
+  return {
+    filePath: "src/trigger/example.ts",
+    exportName: "exampleTask",
+    ...partial,
+  } as any;
+}
+
+describe("assertNoDuplicateTaskIds", () => {
+  it("does not throw when all task ids are unique", () => {
+    const tasks = [task({ id: "a" }), task({ id: "b" }), task({ id: "c" })];
+
+    expect(() => assertNoDuplicateTaskIds(tasks)).not.toThrow();
+  });
+
+  it("throws a ServiceValidationError when a task id is duplicated", () => {
+    const tasks = [task({ id: "a" }), task({ id: "a" })];
+
+    expect(() => assertNoDuplicateTaskIds(tasks)).toThrow(ServiceValidationError);
+  });
+
+  it("reports a 400 and names the duplicate id and its files", () => {
+    const tasks = [
+      task({ id: "report", filePath: "src/trigger/report.ts" }),
+      task({ id: "report", filePath: "src/trigger/scheduled.ts" }),
+    ];
+
+    let error: unknown;
+    try {
+      assertNoDuplicateTaskIds(tasks);
+    } catch (e) {
+      error = e;
+    }
+
+    expect(error).toBeInstanceOf(ServiceValidationError);
+    const validationError = error as ServiceValidationError;
+    expect(validationError.status).toBe(400);
+    expect(validationError.message).toContain("report");
+    expect(validationError.message).toContain("src/trigger/report.ts");
+    expect(validationError.message).toContain("src/trigger/scheduled.ts");
+  });
+
+  it("detects duplicates across different task types (a schedule and a regular task sharing an id)", () => {
+    const tasks = [
+      task({ id: "report", triggerSource: undefined, filePath: "src/trigger/report.ts" }),
+      task({ id: "report", triggerSource: "schedule", filePath: "src/trigger/scheduled.ts" }),
+    ];
+
+    expect(() => assertNoDuplicateTaskIds(tasks)).toThrow(ServiceValidationError);
+  });
+});