regarding unit testing in node js with sinon - node.js

Question

class FetchTenant {
constructor (){
this.Config = this._getConfig();
this.Token = this._getToken();
this.TenantMap = new Map();
}
async getTenantId(Id){
if(!this.TenantMap[Id]){
const serviceid = await this._getInfo(Id, false);
this.TenantMap[Id] = serviceid;
}
return this.TenantMap[Id];
}
_getConfig() {
return get_env_from_local({ name: 'env_1' });
}
async _getToken() {
const options = {
method: 'POST',
uri: `${this.Config.url}`,
json: true,
resolveWithFullResponse: false,
transform2xxOnly: true,
transform: body => body.access_token,
auth: {
username: this.Config.clientid,
password: this.Config.clientsecret
},
form: {
grant_type: 'client_credentials'
},
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json'
}
};
return request(options)
.catch(err => {
logger.error('Could not get Token', err.statusCode, err.message);
return null;
});
}
async _getInfo(Id, newtoken) {
if(newtoken){
this.accessToken = await this._getToken();
if(this.accessToken == null){
logger.error(`fetching token failed`);
return null;
}
}
const options = {
method: 'GET',
uri: `${this.Config.url}/xyz/${Id}`,
json: true,
resolveWithFullResponse: false,
transform2xxOnly: true,
transform: body => body.tenantId,
auth: {
bearer: this.accessToken
},
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json',
}
};
return request(options)
.catch(err => {
if(err.statusCode != 401) {
logger.error(`Could not get tenant id`, err.statusCode, err.message);
return null;
}
else {
return this._getServiceInstanceInfo(Id, true);
}
});
}
}
module.exports = FetchTenant;
this is the class that i have created.
how to write a unit test for this class using sinon (stub and mock),i have to test only the public functions and the only public function here is getTenantId(Id) where in all the other private functions have a http request which can give either a valid response or an error.
is there any way to test the public function by mocking all the other private functions. i want to pre-define the data which will be returned by each private function and the primary data they fetch from env and use to send the request.

Answer 1

You can use nock (https://www.npmjs.com/package/nock) to mock all your http calls and test the public function you would normally do.