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-dialect.test.ts

@@ -0,0 +1,112 @@
+import { CompiledQuery } from "kysely";
+import { describe, it, expect, vi } from "vitest";
+
+import { PreviewDODialect } from "../../src/db/do-dialect.js";
+import type { PreviewDODialectConfig } from "../../src/db/do-dialect.js";
+
+function createMockStub(queryFn = vi.fn()) {
+	return { query: queryFn };
+}
+
+function createConfig(queryFn = vi.fn()): PreviewDODialectConfig {
+	const stub = createMockStub(queryFn);
+	return { getStub: () => stub };
+}
+
+describe("PreviewDODialect", () => {
+	it("creates a SqliteAdapter", () => {
+		const dialect = new PreviewDODialect(createConfig());
+		const adapter = dialect.createAdapter();
+		expect(adapter.constructor.name).toBe("SqliteAdapter");
+	});
+
+	it("creates a SqliteQueryCompiler", () => {
+		const dialect = new PreviewDODialect(createConfig());
+		const compiler = dialect.createQueryCompiler();
+		expect(compiler.constructor.name).toBe("SqliteQueryCompiler");
+	});
+});
+
+describe("PreviewDODriver", () => {
+	it("acquires a connection", async () => {
+		const dialect = new PreviewDODialect(createConfig());
+		const driver = dialect.createDriver();
+		const conn = await driver.acquireConnection();
+		expect(conn).toBeDefined();
+		expect(conn.executeQuery).toBeTypeOf("function");
+	});
+
+	it("transaction methods are no-ops (preview is read-only)", async () => {
+		const dialect = new PreviewDODialect(createConfig());
+		const driver = dialect.createDriver();
+		const conn = await driver.acquireConnection();
+
+		// These should not throw
+		await driver.beginTransaction(conn, {});
+		await driver.commitTransaction(conn);
+		await driver.rollbackTransaction(conn);
+	});
+});
+
+describe("PreviewDOConnection", () => {
+	it("passes sql and parameters to the stub", async () => {
+		const queryFn = vi.fn().mockResolvedValue({ rows: [], changes: 0 });
+		const dialect = new PreviewDODialect(createConfig(queryFn));
+		const driver = dialect.createDriver();
+		const conn = await driver.acquireConnection();
+
+		await conn.executeQuery(CompiledQuery.raw("SELECT * FROM users WHERE id = ?", ["abc"]));
+
+		expect(queryFn).toHaveBeenCalledWith("SELECT * FROM users WHERE id = ?", ["abc"]);
+	});
+
+	it("returns rows from the stub result", async () => {
+		const rows = [
+			{ id: "1", name: "Alice" },
+			{ id: "2", name: "Bob" },
+		];
+		const queryFn = vi.fn().mockResolvedValue({ rows, changes: 0 });
+		const dialect = new PreviewDODialect(createConfig(queryFn));
+		const driver = dialect.createDriver();
+		const conn = await driver.acquireConnection();
+
+		const result = await conn.executeQuery(CompiledQuery.raw("SELECT * FROM users"));
+
+		expect(result.rows).toEqual(rows);
+	});
+
+	it("converts changes to bigint numAffectedRows", async () => {
+		const queryFn = vi.fn().mockResolvedValue({ rows: [], changes: 3 });
+		const dialect = new PreviewDODialect(createConfig(queryFn));
+		const driver = dialect.createDriver();
+		const conn = await driver.acquireConnection();
+
+		const result = await conn.executeQuery(CompiledQuery.raw("UPDATE users SET name = ?", ["x"]));
+
+		expect(result.numAffectedRows).toBe(3n);
+	});
+
+	it("sets numAffectedRows to undefined when changes is undefined", async () => {
+		const queryFn = vi.fn().mockResolvedValue({ rows: [{ count: 5 }] });
+		const dialect = new PreviewDODialect(createConfig(queryFn));
+		const driver = dialect.createDriver();
+		const conn = await driver.acquireConnection();
+
+		const result = await conn.executeQuery(
+			CompiledQuery.raw("SELECT count(*) as count FROM users"),
+		);
+
+		expect(result.numAffectedRows).toBeUndefined();
+	});
+
+	it("handles zero changes correctly", async () => {
+		const queryFn = vi.fn().mockResolvedValue({ rows: [], changes: 0 });
+		const dialect = new PreviewDODialect(createConfig(queryFn));
+		const driver = dialect.createDriver();
+		const conn = await driver.acquireConnection();
+
+		const result = await conn.executeQuery(CompiledQuery.raw("DELETE FROM users WHERE 1=0"));
+
+		expect(result.numAffectedRows).toBe(0n);
+	});
+});