webextension-rpc/test

import test from 'ava'
import sinon from 'ts-sinon'

import { RpcClient, RpcError, RemoteError, injectRpcInfo } from '../src/RpcClient'

function mockBrowser() {
	return {
		runtime: {
			sendMessage: sinon.spy(async (...args) => {}),
		},
		tabs: {
			sendMessage: sinon.spy(async (...args) => {}),
		},
	}
}

let browser = mockBrowser()

test.beforeEach(() => {
	// We mock the browser globally. Note we therefore need to test serially to prevent the tests from
	// interfering with each other.
	global.browser = browser = mockBrowser()
})

test.serial('should create a function', t => {
	const remoteFunc = new RpcClient({ tabId: 1 }).func('remoteFunc')
	t.is(remoteFunc.name, 'remoteFunc_RPC')
	t.is(typeof remoteFunc, 'function')
})

test.serial('should throw an error when unable to sendMessage', async t => {
	const remoteFunc = new RpcClient({ tabId: 1 }).func('remoteFunc')
	browser.tabs.sendMessage = async () => { throw new Error() }
	await t.throwsAsync(remoteFunc, {
		instanceOf: RpcError,
		message: `Got no response when trying to call 'remoteFunc'. Did you enable RPC in the tab's content script?`,
	})
})

test.serial('should call the browser.tabs function when tabId is given', async t => {
	const remoteFunc = new RpcClient({ tabId: 1 }).func('remoteFunc')
	try {
		await remoteFunc()
	} catch (e) {}
	t.true(browser.tabs.sendMessage.calledOnce)
	t.true(browser.runtime.sendMessage.notCalled)
})

test.serial('should call the browser.runtime function when tabId is undefined', async t => {
	const remoteFunc = new RpcClient().func('remoteFunc')
	try {
		await remoteFunc()
	} catch (e) {}
	t.true(browser.tabs.sendMessage.notCalled)
	t.true(browser.runtime.sendMessage.calledOnce)
})

test.serial('should call the browser.tabs function when tabId is overridden', async t => {
	const remoteFunc = new RpcClient().func('remoteFunc', { tabId: 123 })
	try {
		await remoteFunc()
	} catch (e) {}
	t.true(browser.tabs.sendMessage.calledOnce)
	t.true(browser.runtime.sendMessage.notCalled)
})

test.serial('should call the browser.runtime function when tabId is overridden as null', async t => {
	const remoteFunc = new RpcClient({ tabId: 123 }).func('remoteFunc', { tabId: null })
	try {
		await remoteFunc()
	} catch (e) {}
	t.true(browser.tabs.sendMessage.notCalled)
	t.true(browser.runtime.sendMessage.calledOnce)
})

test.serial('should send the call message correctly', async t => {
	const remoteFunc = new RpcClient().func('remoteFunc')
	try {
		await remoteFunc('a', 'b', 'c', 'd')
	} catch {}
	t.true(browser.runtime.sendMessage.calledOnce)
	t.deepEqual(browser.runtime.sendMessage.lastCall.args, [{
		__WEBEXTENSION_RPC_MESSAGE__: '__RPC_CALL__',
		funcName: 'remoteFunc',
		args: ['a', 'b', 'c', 'd'],
		addRpcInfoAsArgument: false,
	}])
})

test.serial('should handle the RpcInfoSymbol', async t => {
	const remoteFunc = new RpcClient().func('remoteFunc')
	try {
		await remoteFunc('a', 'b', injectRpcInfo, 'd')
	} catch {}
	t.true(browser.runtime.sendMessage.calledOnce)
	t.deepEqual(browser.runtime.sendMessage.lastCall.args, [{
		__WEBEXTENSION_RPC_MESSAGE__: '__RPC_CALL__',
		funcName: 'remoteFunc',
		args: ['a', 'b', null, 'd'],
		addRpcInfoAsArgument: 2,
	}])
})

test.serial('should throw an "interfering listener" error if response is unrecognised', async t => {
	browser.tabs.sendMessage = async () => 'some unexpected return value'
	const remoteFunc = new RpcClient({ tabId: 1 }).func('remoteFunc')
	await t.throwsAsync(remoteFunc, {
		instanceOf: RpcError,
		message: /RPC got a response from an interfering listener/,
	})
})

test.serial('should throw a "no response" error if response is undefined', async t => {
	// It seems we can get back undefined when the tab is closed before the response is sent.
	// In such cases 'no response' seems a better error message than 'interfering listener'.
	browser.tabs.sendMessage = async () => undefined
	const remoteFunc = new RpcClient({ tabId: 1 }).func('remoteFunc')
	await t.throwsAsync(remoteFunc, {
		instanceOf: RpcError,
		message: /Got no response/,
	})
})

test.serial('should throw RemoteError if the response contains an error message', async t => {
	browser.tabs.sendMessage = async () => ({
		__WEBEXTENSION_RPC_MESSAGE__: '__RPC_RESPONSE__',
		errorMessage: 'Remote function error',
	})
	const remoteFunc = new RpcClient({ tabId: 1 }).func('remoteFunc')
	await t.throwsAsync(remoteFunc, {
		instanceOf: RemoteError,
		message: 'Remote function error',
	})
})

test.serial('should return the value contained in the response', async t => {
	browser.tabs.sendMessage = async () => ({
		__WEBEXTENSION_RPC_MESSAGE__: '__RPC_RESPONSE__',
		returnValue: 'Remote function return value',
	})
	const remoteFunc = new RpcClient({ tabId: 1 }).func('remoteFunc')
	t.is(await remoteFunc(), 'Remote function return value')
})