Develop Reference

NodeJS: My jest spyOn function is not being called

I don't understand why my spy is not being used. I have used this code elsewhere and it has worked fine.
Here is my test:
const {DocumentEngine} = require('../documentEngine')
const fileUtils = require('../utils/fileUtils')
const request = {...}
const fieldConfig = {...}
test('If the Carbone addons file is not found, context is built with the carboneAddons property as an empty object', async () => {
const expectedResult = {
carboneAddons: {},
}
const fileExistSpy = jest
.spyOn(fileUtils, 'checkFileExists')
.mockResolvedValue(false)
const result = await docEngine.buildContext(request, fieldConfig)
expect(fileExistSpy).toHaveBeenCalledTimes(1)
})
Here is the code that it is being tested:
async function buildContextForLocalResources(request, fieldConfig) {
/* other code */
const addonFormatters = await getCarboneAddonFormatters()
const context = {
sourceJson,
addonFormatters,
documentFormat,
documentTemplateId,
documentTemplateFile,
responseType,
jsonTransformContext
}
return context
}
async function getCarboneAddonFormatters() {
const addOnPath = path.resolve(
docConfig.DOC_GEN_RESOURCE_LOCATION,
'library/addon-formatters.js'
)
if (await checkFileExists(addOnPath)) {
logger.info('Formatters found and are being used')
const {formatters} = require(addOnPath)
return formatters
}
logger.info('No formatters were found')
return {}
}
This is the code from my fileUtils file:
const fs = require('fs/promises')
async function checkFileExists(filePath) {
try {
await fs.stat(filePath)
return true
} catch (e) {
return false
}
}
My DocumentEngine class calls the buildContext function which in turn calls the its method getCarboneAddonFormatters. The fileUtils is outside of DocumentEngine class in a utilities folder. The original code I had this working on was TypeScript as opposed to this which is just NodeJS Javascript. The config files for both are the same. When I try to step through the code (VSCode debugger), as soon as I hit the line with await fs.stat(filePath) in the checkFileExists function, it kicks me out of the test and moves on to the next test - no error messages or warnings.
I've spent most of the day trying to figure this out. I don't think I need to do an instance wrapper for the documentEngine, because checkFileExists is not a class member, and that looks like a React thing...
Any help in getting this to work would be appreciated.

How to make proper unit test of async function?

I have a function which checks url address and returns true if that address is valid or no.
I need to write tests to that using Jest. To complete this task I wrote testcase which located in the bottom of the document. At first it threw regenerator-runtime error, but I fixed that with according import. But then it started to throw that error. To fix it, I tried to import fetch library, but error didn't solved. Despite that error function in my app working normally. How to fix that error?
ReferenceError: fetch is not defined
const fetch = require('node-fetch');
test("Testing valid product", async ()=>{
const result = await valid('#products/1');
expect(result).toBe(true);
});
My function
//FUNCTION WITH VALIDATION
export async function valid(path){
//GETTING GROUP OF THE PRODUCTS
let group = path.substr(path.indexOf('#')+1,path.indexOf('/')-1);
//GET ID OF ITEM OF THE GROUP
let url = path.substr(path.indexOf('/')+1);
if(group=='products'){
//CHECKING IF ITEM WITH THAT ID EXISTS
let items = await fetch('https://my-json-server.typicode.com/ValeryDrozd/Valerydrozd.github.io/products').then(res => res.json());
for(let i=0;i<items.length;i++){
if(String(items[i]['id'])==url)return true;
}
return false;
}
if(group=='promos'){
let items = await fetch('https://my-json-server.typicode.com/ValeryDrozd/Valerydrozd.github.io/promos').then(res => res.json());
for(let i=0;i<items.length;i++){
if(String(items[i]['id'])==url)return true;
}
return false;
}
if(group=='order'){
let orders = JSON.parse(localStorage.getItem('orders'));
if(orders==null)return false;
if(orders['orderids'].indexOf(url)==-1)return false;
return true;
}
return false;
}
My jest.config.js file
module.exports = {
collectCoverage: true,
transform: { '\\.js$': 'babel-jest', },
};

I think you could resolve this issue by either using jest-fetch-mock or create a mock fetch on your own before your test as following:
// Mock at global level
global.fetch = jest.fn(() =>
Promise.resolve({
json: () => Promise.resolve({/* whatever you want to ressolve */}),
})
);
test("Testing valid product", async ()=>{
const result = await valid('#products/1');
expect(result).toBe(true);
});

slack bot sending direct message to user using aws lambda function

I'm trying to send a direct message using slack web api to a user but I think my getSlackUser method which gets all the available users does not complete in time for when I call slackId;
the console.log(slackId) gives undefined meaning it doesn't complete my api call with bolt
how do I ensure getSlackUser method finishes (make it blocking) before it moves on to the rest?
const { WebClient } = require('#slack/web-api');
const { App } = require('#slack/bolt')
const rtm = new RTMClient(process.env.SLACK_OAUTH_TOKEN);
const web = new WebClient(process.env.SLACK_OAUTH_TOKEN);
const app = new App({
token: process.env.SLACK_OAUTH_TOKEN,
signingSecret: process.env.SLACK_SIGNING_SECRET
});
exports.handler = async (event) => {
const slackId = await getSlackUser('example_real_name').id;
console.log(slackId);
await sendSlackMessage(slackId, 'Bot message');
}
sendSlackMessage = async (channel, message) => {
await web.chat.postMessage({
channel: channel,
text: message,
as_user: true
});
}
getSlackUser = async(real_name) => {
const result = await app.client.users.list({
token: process.env.SLACK_OAUTH_TOKEN
});
console.log(result);
return result.members.find((user) => user.real_name == real_name);
}

The problem is precedence on this line:
const slackId = await getSlackUser('example_real_name').id;
Since member access has a higher precedence (evaluated before) than await, it is effectively the same as:
const slackId = await (getSlackUser('example_real_name').id);
getSlackUser returns a Promise object, then its id member is undefined. Await waits for the undefined, which is undefined.
To fix this, make sure that the await is evaluated before the .id:
const slackId = (await getSlackUser('example_real_name')).id;

MongoDB reusable custom javascript module

I would like to create a local Javascript module I can "require" in other files to handle all MongoDB CRUD operations.
I wrote something as:
-- dbConn.js file --
require('dotenv').config()
const MongoClient = require('mongodb').MongoClient
const ObjectID = require('mongodb').ObjectID
let _connection
const connectDB = async () => {
try {
const client = await MongoClient.connect(process.env.MONGO_DB_URI, {
useNewUrlParser: true,
useUnifiedTopology: true
})
console.log('Connected to MongoDB')
return client
} catch (err) {
console.log(error)
}
}
exports.findOne = async () => {
let client = await connectDB()
if (!client) {
return;
}
try {
const db = client.db("Test_DB");
const collection = db.collection('IoT_data_Coll');
const query = {}
let res = await collection.findOne(query);
return res;
} catch (err) {
console.log(err);
} finally {
client.close();
}
}
exports.findAll = async () => {
let client = await connectDB()
if (!client) {
return;
}
try {
const db = client.db("Test_DB");
const collection = db.collection('IoT_data_Coll');
const query = {}
let res = await collection.find(query).toArray();
return res;
} catch (err) {
console.log(err);
} finally {
client.close();
}
}
Then in another file (not necessary inside Express app), say
-- app.js ---
const findAll = require('./dbConn').findAll
const findOne = require('./dbConn').findOne
findAll().then(res => JSON.stringify(console.log(res)))
findOne().then(res => JSON.stringify(console.log(res)))
I wonder if it is correct?
I have to close the connection after each method/CRUD operation?
I was trying to use IIF instead of ".then", as:
(async () => {
console.log(await findOne())
})()
But I receive a weird error saying that findAll is not a function.
What's wrong with it?
Thanks.

It really depends on your use case which isn’t clear If you are using Express or just stand alone and how frequent are you planning to run app.js
Either way your code is expensive, each time you reference dbCon.js you are opening a new connection to the database.
So you can fix app.js by only requiring dbCon.js once and use it..
The best practice is to ofcourse use connection pooling https://www.compose.com/articles/connection-pooling-with-mongodb/

Node.js: Awaiting a Require

I'm new the Node.js and I've been working with a sample project by a third party provider and I'm trying to use Azure Key Vault to store configuration values.
I'm having trouble getting a process to wait before executing the rest. I'll try to detail as much as I know.
The sample project has a file named agent.js which is the start page/file. On line 16 (agent_config = require('./config/config.js')[process.env.LP_ACCOUNT][process.env.LP_USER]) it calls a config file with values. I'm trying to set these value using Key Vault. I've tried many combinations of calling functions, and even implementing async / await but the value for agent_config always contains a [Promise] object and not the data returned by Key Vault.
If I'm right, this is because the Key Vault itself uses async / await too and the config file returns before the Key Vault values are returned.
How can Key Vault be added/implemented in a situation like this?
Here's what I've tried:
First updated agent.js to
let agent_config = {};
try {
agent_config = require('./config/config.js')['123']['accountName'];
} catch (ex) {
log.warn(`[agent.js] Error loading config: ${ex}`)
}
console.log(agent_config);
Test 1
./config/config.js
const KeyVault = require('azure-keyvault');
const msRestAzure = require('ms-rest-azure');
const KEY_VAULT_URI = 'https://' + '{my vault}' + '.vault.azure.net/' || process.env['KEY_VAULT_URI'];
function getValue(secretName, secretVersion) {
msRestAzure.loginWithAppServiceMSI({ resource: 'https://vault.azure.net' }).then((credentials) => {
const client = new KeyVault.KeyVaultClient(credentials);
client.getSecret(KEY_VAULT_URI, secretName, secretVersion).then(
function (response) {
return response.Value;
});
});
}
module.exports = {
'123': {
'accountName': {
accountId: getValue('mySecretName', '')
}
}
};
Results
{ accountsId: undefined }
Test 2
Made getValue an async function and wrapped it around another function (tried without the wrapping and didn't work either)
./config/config.js
const KeyVault = require('azure-keyvault');
const msRestAzure = require('ms-rest-azure');
const KEY_VAULT_URI = 'https://' + '{my vault}' + '.vault.azure.net/' || process.env['KEY_VAULT_URI'];
async function getValue(secretName, secretVersion) {
msRestAzure.loginWithAppServiceMSI({ resource: 'https://vault.azure.net' }).then((credentials) => {
const client = new KeyVault.KeyVaultClient(credentials);
client.getSecret(KEY_VAULT_URI, secretName, secretVersion).then(
function (response) {
return response.Value;
});
});
}
async function config() {
module.exports = {
'123': {
'accountName': {
accountId: await getValue('mySecretName', '')
}
}
};
}
config();
Results
{}
Test 3
Made getValue an async function and wrapped it around another function (tried without the wrapping and didn't work either)
./config/config.js
const KeyVault = require('azure-keyvault');
const msRestAzure = require('ms-rest-azure');
const KEY_VAULT_URI = 'https://' + '{my vault}' + '.vault.azure.net/' || process.env['KEY_VAULT_URI'];
async function getValue(secretName, secretVersion) {
return msRestAzure.loginWithAppServiceMSI({ resource: 'https://vault.azure.net' })
.then((credentials) => {
const client = new KeyVault.KeyVaultClient(credentials);
return client.getSecret(KEY_VAULT_URI, secretName, secretVersion).then(
function (response) {
return response.Value;
});
});
}
module.exports = {
'123': {
'accountName': {
accountId: getValue('mySecretName', '')
}
}
};
config();
Results
{ accountId: { <pending> } }
Other
I've tried many others ways like module.exports = async (value) =< {...} (found through other questions/solutions without success.
I'm starting to think I need to do some "waiting" on agent.js but I haven't found good info on this.
Any help would be great!

One issue is that your getValue function is not returning anything as your returns need to be explicit.
(and without the promise being returned, there's nothing to await on)
async function getValue(secretName, secretVersion) {
return msRestAzure.loginWithAppServiceMSI({ resource: 'https://vault.azure.net' })
.then((credentials) => {
const client = new KeyVault.KeyVaultClient(credentials);
return client.getSecret(KEY_VAULT_URI, secretName, secretVersion).then(
function (response) {
return response.Value;
});
});
}
You could also get away with less explicit returns using arrow functions..
const getValue = async (secretName, secretVersion) =>
msRestAzure.loginWithAppServiceMSI({ resource: 'https://vault.azure.net' })
.then(credentials => {
const client = new KeyVault.KeyVaultClient(credentials);
return client.getSecret(KEY_VAULT_URI, secretName, secretVersion)
.then(response => response.Value);
});
Introducing the Azure Key Vault read, which is async, means your whole config read is async. There' nothing you can do to get around that. This will mean that the code that uses the config will need to handle it appropriately. You start by exporting an async function that will return the config..
async function getConfig() {
return {
'123': {
'accountName': {
accountId: await getValue('mySecretName', '')
}
}
};
}
module.exports = getConfig;
In your agent code you call that function. This will mean that your agent code will need to be wrapped in a function too, so maybe something like this..
const Bot = require('./bot/bot.js');
const getConfig = require('./config/config.js');
getConfig().then(agentConfig => {
const agent = new Bot(agentConfig);
agent.on(Bot.const.CONNECTED, data => {
log.info(`[agent.js] CONNECTED ${JSON.stringify(data)}`);
});
});

The package azure-keyvault has been deprecated in favor of the new packages to deal with Keyvault keys, secrets and certificates separately. For your scenario, you can use the new #azure/keyvault-secrets package to talk to Key Vault and the new #azure/identity package to create the credential.
const { SecretClient } = require("#azure/keyvault-secrets");
const { DefaultAzureCredential } = require("#azure/identity");
async function getValue(secretName, secretVersion) {
const credential = new DefaultAzureCredential();
const client = new SecretClient(KEY_VAULT_URI, credential);
const secret = await client.getSecret(secretName);
return secret.value;
}
The DefaultAzureCredential assumes that you have set the below env variables
AZURE_TENANT_ID: The tenant ID in Azure Active Directory
AZURE_CLIENT_ID: The application (client) ID registered in the AAD tenant
AZURE_CLIENT_SECRET: The client secret for the registered application
To try other credentials, see the readme for #azure/identity
If you are moving from the older azure-keyvault package, checkout the migration guide to understand the major changes