refactor: centralize event dialog form state

tests/event-form.test.ts

@@ -0,0 +1,73 @@
+import { describe, expect, test } from "bun:test";
+import {
+	getDefaultEventFormValues,
+	getEventFormValuesFromEvent,
+	validateEventFormValues,
+} from "@/lib/event-form";
+
+describe("event form defaults and validation", () => {
+	test("returns manual-create defaults with blank values", () => {
+		expect(getDefaultEventFormValues()).toEqual({
+			title: "",
+			description: "",
+			location: "",
+			url: "",
+			start: "",
+			end: "",
+			allDay: false,
+			recurrenceRule: undefined,
+		});
+	});
+
+	test("maps edit and AI-prefilled events into form values", () => {
+		const values = getEventFormValuesFromEvent({
+			title: "AI Draft",
+			location: "Studio A",
+			start: "2026-04-09T10:00:00.000Z",
+			recurrenceRule: "FREQ=WEEKLY;INTERVAL=1;BYDAY=TH",
+		});
+
+		expect(values.title).toBe("AI Draft");
+		expect(values.location).toBe("Studio A");
+		expect(values.start).toBe("2026-04-09T10:00:00.000Z");
+		expect(values.recurrenceRule).toBe("FREQ=WEEKLY;INTERVAL=1;BYDAY=TH");
+	});
+
+	test("requires title and start values", () => {
+		const result = validateEventFormValues(getDefaultEventFormValues());
+
+		expect(result.success).toBe(false);
+		if (!result.success) {
+			expect(result.error.flatten().fieldErrors.title?.[0]).toContain("Title is required");
+			expect(result.error.flatten().fieldErrors.start?.[0]).toContain("Start date is required");
+		}
+	});
+
+	test("requires end to be after start when present", () => {
+		const result = validateEventFormValues({
+			...getDefaultEventFormValues(),
+			title: "Planning",
+			start: "2026-04-09T10:00:00.000Z",
+			end: "2026-04-09T09:30:00.000Z",
+		});
+
+		expect(result.success).toBe(false);
+		if (!result.success) {
+			expect(result.error.flatten().fieldErrors.end?.[0]).toContain("after the start date");
+		}
+	});
+
+	test("requires an optional URL to be valid when provided", () => {
+		const result = validateEventFormValues({
+			...getDefaultEventFormValues(),
+			title: "Planning",
+			start: "2026-04-09T10:00:00.000Z",
+			url: "not-a-url",
+		});
+
+		expect(result.success).toBe(false);
+		if (!result.success) {
+			expect(result.error.flatten().fieldErrors.url?.[0]).toContain("valid URL");
+		}
+	});
+});