How do I query mysql database by using promises in protractor

Question

How do I query mysql database by using promises in protractor?

I would like to execute different queries multiple times during test execution but my executeSelectQuery function executes in the beginning of the test and not in the end. How can I overcome this by using promises?

I also need to access the object inside executeSelectQuery and I am not being able to. Function returns undefined.

Below code is how my executeSelectQuery function looks like:

function executeSelectQuery(sql){
connectDatabase.connection.query(sql, function(err, data) {
    var result;
    if (err) {
        throw new Error('[ FAIL ] - Unsuccessful query execution!!!');
    }
    else{
        result = data[0].user;
        log.info('[ SUCCESS ] - Query executed successfully: ' + sql + ' with the following result ==> ' + result);
        return result;
    }
  });

}

This is how my test looks like:

it('Should navigate to webpage..', function(){
    log.info("Test is being executed..");
    login.goTo(parameters.url);
    login.login(parameters.username, parameters.password);
    helper.executeSelectQuery(query_select);
});

Answer 1

Just make your executeSelectQuery() function return a promise that resolves with the data.

executeSelectQuery = (sql) => {
    return new Promise((resolve, reject) => {
        connectDatabase.connection.query(sql, (err, data) => {
            if(err) {
                reject(err);
            }
            resolve(data);
        });
    });
}

Then resolve it in your tests

executeSelectQuery().then((data) => {
    console.log(data);
})

Answer 2

Keep query functions call in separate 'it' block in the last .

describe('Overall Test Suite',function() {
 var expectedResult; //global variable for all 'it' blocks inside suite.
 it('Should navigate to webpage..', function(){
    log.info("Test is being executed..");
    login.goTo(parameters.url);
    login.login(parameters.username, parameters.password);
  });

it('Executing Queries', function(){
    expect(helper.executeSelectQuery(query_select)).toBeEqual(expectedResult);//let jasmine resolve the promise implicitly
 });
});