Chaining a similar promise ambiguity in Protractor - promise

Question

I am using EXCELJS to read data from Excel file . Created a function,allinExcel which returns the column values in promise . As I need 2 columns , I have chained the similar promise functions - allinExcel . In this context , yet times , I get the expected results and yet times I don't ,which is ambiguous . The ProExcel file consists of 2 columns .The expected result from the below code is 2 arrays which includes each of the column contents . Any help in this is very much useful.
The expected result is [ <1 empty item>, 'GEL', 'BEL', 'HEL', 'SEL' ] [ <1 empty item>, 55, 555, 66, 666 ]
But if I get a column value using a single promise , I get the result every time without any ambiguity .
describe("Excel Read ",function(){
function allinExcel(colNum){
var Excel = require('exceljs');
var workbook = new Excel.Workbook();
var excelFilePath = "ExcelData/ProExcel.xlsx"
return workbook.xlsx.readFile(excelFilePath).then(function() {
var worksheet=workbook.getWorksheet('Sheet1');
return worksheet.getColumn(colNum+1).values
},function(error){
console.log(error)
return fail
})
}
it("Excel Operation",function(){
allinExcel(0).then(function(col0){
allinExcel(1).then(function(col1){
console.log(col1,col0)
})
})
})
The following is the conf.js file
// conf.js
var Jasmine2HtmlReporter = require('protractor-jasmine2-html-reporter');
exports.config = {
seleniumAddress: 'http://localhost:4444/wd/hub',
getPageTimeout:20000, // browser.get timeout
allScriptsTimeout: 360000, // Time to load the DOM
jasmineNodeOpts: {defaultTimeoutInterval: 50000}, //For individual it
framework: 'jasmine',
capabilities: {
'browserName': 'chrome',
chromeOptions: {
args: [
'--start-maximized','disable-infobars'//,'--headless'
]
}
},
onPrepare: function() {
global.EC = protractor.ExpectedConditions,
jasmine.getEnv().addReporter(
new Jasmine2HtmlReporter({
savePath: 'target/reports',
screenshotsFolder: 'images',
takeScreenshots: true,
takeScreenshotsOnlyOnFailures: true,
fixedScreenshotName: false,
fileName: 'currentRun',
cleanDestination: true
})
);
},
jasmineNodeOpts: {
showColors: true, // Use colors in the command line report.
},
specs: ['specs/WebTables.js'],
};

Answer 1

Please try your function and code in a javascript file without using protractor to see your code can work well or not.
Create a temp folder
New a file with name: test.js in the temp folder, and copy following code into the file.
Copy the excel ProExcel.xlsx into the temp folder
Open an cmd window and enter the temp folder
Run node test.js in cmd window
// test.js
function allinExcel(colNum) {
var Excel = require('exceljs');
var workbook = new Excel.Workbook();
var excelFilePath = "ProExcel.xlsx"
return workbook.xlsx.readFile(excelFilePath).then(function () {
var worksheet = workbook.getWorksheet('Sheet1');
return worksheet.getColumn(colNum + 1).values
}, function (error) {
console.log(error)
return fail
})
}
[1, 2, 3, 4, 5, 6, 7].forEach(function (it, index) {
allinExcel(0).then(function (col0) {
allinExcel(1).then(function (col1) {
console.log('\n#### ' + index)
console.log(col0, col1)
})
})
})
If you can't get same result in each loop, change your nodejs version(I used v10.9.0).
If you can get same result in each loop, the problem comes from Protractor side.
Add return for each nested function for then(), run again.
it("Excel Operation",function(){
allinExcel(0).then(function(col0){
return allinExcel(1).then(function(col1){
return console.log(col1,col0)
})
})
})