invokeExpressSynthetic

function invokeExpressSynthetic(
	app: Express,
	opts: {
		method: HttpMethod
		path: string
		headers?: Record<string, string>
		body?: unknown
	},
): Promise<{
	statusCode: number
	headers: Record<string, string>
	bodyText: string
	bodyJson: unknown
}>

Behavior

• Binds an ephemeral HTTP server on 127.0.0.1 with a random port.
• Issues a fetch with the given method, path (leading / optional), optional headers, and JSON body for mutating methods (sets content-type: application/json when body is set and not overridden).
• Parses JSON response bodies when possible; otherwise returns raw text in bodyJson as a string.
• Always closes the server in a finally block.

When to use

• Integration tests that need real req / res / middleware behavior without deploying.
• Tooling that drives an Express app the same way external HTTP would.

See also

• HTTP bridge — map RPC to synthetic HTTP for QA