Emdash source with visual editor image upload fix

Fixes:
1. media.ts: wrap placeholder generation in try-catch
2. toolbar.ts: check r.ok, display error message in popover

packages/cloudflare/tests/db/do-preview-sign.test.ts

@@ -0,0 +1,94 @@
+import { describe, it, expect } from "vitest";
+
+import { signPreviewUrl, verifyPreviewSignature } from "../../src/db/do-preview-sign.js";
+
+const SECRET = "test-secret-key";
+const DIGITS = /^\d+$/;
+const HEX_64 = /^[0-9a-f]{64}$/;
+
+describe("signPreviewUrl", () => {
+	it("returns a URL with source, exp, and sig params", async () => {
+		const url = await signPreviewUrl("https://preview.example.com", "https://mysite.com", SECRET);
+		const parsed = new URL(url);
+
+		expect(parsed.origin).toBe("https://preview.example.com");
+		expect(parsed.searchParams.get("source")).toBe("https://mysite.com");
+		expect(parsed.searchParams.get("exp")).toMatch(DIGITS);
+		expect(parsed.searchParams.get("sig")).toMatch(HEX_64);
+	});
+
+	it("sets expiry based on ttl", async () => {
+		const before = Math.floor(Date.now() / 1000);
+		const url = await signPreviewUrl(
+			"https://preview.example.com",
+			"https://mysite.com",
+			SECRET,
+			7200,
+		);
+		const after = Math.floor(Date.now() / 1000);
+
+		const exp = Number(new URL(url).searchParams.get("exp"));
+		expect(exp).toBeGreaterThanOrEqual(before + 7200);
+		expect(exp).toBeLessThanOrEqual(after + 7200);
+	});
+
+	it("defaults to 1 hour TTL", async () => {
+		const before = Math.floor(Date.now() / 1000);
+		const url = await signPreviewUrl("https://preview.example.com", "https://mysite.com", SECRET);
+		const exp = Number(new URL(url).searchParams.get("exp"));
+		expect(exp).toBeGreaterThanOrEqual(before + 3600);
+	});
+});
+
+describe("verifyPreviewSignature", () => {
+	it("verifies a signature produced by signPreviewUrl", async () => {
+		const url = await signPreviewUrl("https://preview.example.com", "https://mysite.com", SECRET);
+		const parsed = new URL(url);
+		const source = parsed.searchParams.get("source")!;
+		const exp = Number(parsed.searchParams.get("exp"));
+		const sig = parsed.searchParams.get("sig")!;
+
+		expect(await verifyPreviewSignature(source, exp, sig, SECRET)).toBe(true);
+	});
+
+	it("rejects a wrong secret", async () => {
+		const url = await signPreviewUrl("https://preview.example.com", "https://mysite.com", SECRET);
+		const parsed = new URL(url);
+		const source = parsed.searchParams.get("source")!;
+		const exp = Number(parsed.searchParams.get("exp"));
+		const sig = parsed.searchParams.get("sig")!;
+
+		expect(await verifyPreviewSignature(source, exp, sig, "wrong-secret")).toBe(false);
+	});
+
+	it("rejects a tampered source", async () => {
+		const url = await signPreviewUrl("https://preview.example.com", "https://mysite.com", SECRET);
+		const parsed = new URL(url);
+		const exp = Number(parsed.searchParams.get("exp"));
+		const sig = parsed.searchParams.get("sig")!;
+
+		expect(await verifyPreviewSignature("https://evil.com", exp, sig, SECRET)).toBe(false);
+	});
+
+	it("rejects a tampered expiry", async () => {
+		const url = await signPreviewUrl("https://preview.example.com", "https://mysite.com", SECRET);
+		const parsed = new URL(url);
+		const source = parsed.searchParams.get("source")!;
+		const sig = parsed.searchParams.get("sig")!;
+
+		expect(await verifyPreviewSignature(source, 9999999999, sig, SECRET)).toBe(false);
+	});
+
+	it("rejects a tampered signature", async () => {
+		const url = await signPreviewUrl("https://preview.example.com", "https://mysite.com", SECRET);
+		const parsed = new URL(url);
+		const source = parsed.searchParams.get("source")!;
+		const exp = Number(parsed.searchParams.get("exp"));
+
+		expect(await verifyPreviewSignature(source, exp, "a".repeat(64), SECRET)).toBe(false);
+	});
+
+	it("rejects a signature with wrong length", async () => {
+		expect(await verifyPreviewSignature("https://x.com", 123, "tooshort", SECRET)).toBe(false);
+	});
+});