/**
* postgres-mcp - Connection Pool Mock
*
* Provides mock implementation of pg Pool and PoolClient
* for testing connection management without real database.
*/
import { vi } from 'vitest';
import type { Pool } from 'pg';
/**
* Create a mock PoolClient
*/
export function createMockPoolClient(): {
query: ReturnType<typeof vi.fn>;
release: (err?: Error | boolean) => void;
} {
return {
query: vi.fn().mockResolvedValue({ rows: [], rowCount: 0 }),
release: vi.fn()
};
}
/**
* Create a mock pg Pool
*/
export function createMockPool(): Partial<Pool> & {
connect: ReturnType<typeof vi.fn>;
query: ReturnType<typeof vi.fn>;
end: ReturnType<typeof vi.fn>;
on: ReturnType<typeof vi.fn>;
} {
const mockClient = createMockPoolClient();
return {
connect: vi.fn().mockResolvedValue(mockClient),
query: vi.fn().mockResolvedValue({ rows: [], rowCount: 0 }),
end: vi.fn().mockResolvedValue(undefined),
on: vi.fn().mockReturnThis(),
totalCount: 10,
idleCount: 8,
waitingCount: 0
};
}
/**
* Create a mock ConnectionPool (our custom wrapper)
*/
export function createMockConnectionPool(): {
execute: ReturnType<typeof vi.fn>;
getStats: ReturnType<typeof vi.fn>;
healthCheck: ReturnType<typeof vi.fn>;
shutdown: ReturnType<typeof vi.fn>;
acquire: ReturnType<typeof vi.fn>;
release: ReturnType<typeof vi.fn>;
} {
const mockClient = createMockPoolClient();
return {
execute: vi.fn().mockResolvedValue({ rows: [], rowCount: 0, executionTimeMs: 5 }),
getStats: vi.fn().mockReturnValue({
total: 10,
active: 2,
idle: 8,
waiting: 0,
totalQueries: 100
}),
healthCheck: vi.fn().mockResolvedValue({ connected: true, latencyMs: 5 }),
shutdown: vi.fn().mockResolvedValue(undefined),
acquire: vi.fn().mockResolvedValue(mockClient),
release: vi.fn()
};
}
/**
* Configure mock pool query responses
*/
export function configureMockPoolQuery(
pool: ReturnType<typeof createMockPool>,
pattern: string,
result: { rows: Record<string, unknown>[]; rowCount: number }
): void {
const originalImpl = pool.query.getMockImplementation() as
((sql: string) => Promise<{ rows: Record<string, unknown>[]; rowCount: number }>) | undefined;
const impl = (sql: string): Promise<{ rows: Record<string, unknown>[]; rowCount: number }> => {
if (sql.includes(pattern)) {
return Promise.resolve(result);
}
if (typeof originalImpl === 'function') {
return originalImpl(sql);
}
return Promise.resolve({ rows: [], rowCount: 0 });
};
// eslint-disable-next-line @typescript-eslint/no-misused-promises
pool.query.mockImplementation(impl);
}
