How can we use the On Prepare function in config File while i am trying to run multiple Spec files - protractor

Question

In the Config File i am using the On Prepare Function for the purpose of assigning the property data test id as value
But for the first spec file execution the on prepare is picked up
but on the next execution of the Spec , the on prepare function is not getting picked up
import { Config } from "protractor/built/config";
import { by } from "protractor";
// import { encode } from "punycode";
function encode(file) {
var stream = require('fs').readFileSync(file);
return new Buffer(stream).toString('base64');
}
export let config: Config = {
// The address of a running selenium server.
//seleniumAddress: 'http://localhost:4444/wd/hub',
directConnect:true,
allScriptsTimeout:1500000,
// Capabilities to be passed to the webdriver instance.
capabilities: {
browserName: 'chrome',
'chromeOptions': {
'extensions': [encode('C:/Users/koanand/Documents/Protractor/ASR/2.2.9_0.crx')]
}
},
onPrepare: function () {
by.addLocator('testId', function(value, parentElement) {
parentElement = parentElement || document;
var nodes = parentElement.querySelectorAll('[data-test-id]');
return Array.prototype.filter.call(nodes, function(node) {
return (node.getAttribute('data-test-id') === value);
});
});
},
// Spec patterns are relative to the configuration file location passed
// to protractor (in this example conf.js).
// They may include glob patterns.
specs: ['C:/Users/anand/Documents/Protractor/ASR/TS-Output/specs/directasr.js',
'C:/Users/anand/Documents/Protractor/ASR/TS-Output/specs/products.js'
],
// Options to be passed to Jasmine-node.
jasmineNodeOpts: {
showColors: true, // Use colors in the command line report.
defaultTimeoutInterval : 150000
}
};
i am observing the below error
Message:
Failed: protractor_1.by.testID is not a function
Stack:
TypeError: protractor_1.by.testID is not a function
at new productlist (C:\Users\koanand\Documents\Protractor\ASR\pageobject\productlist.ts:19:45)
at product.selectingproductlist (C:\Users\koanand\Documents\Protractor\ASR\specs\classproductlist.ts:14:32)
at UserContext.<anonymous> (C:\Users\koanand\Documents\Protractor\ASR\specs\products.ts:21:21)
at C:\Users\koanand\Documents\Protractor\ASR\node_modules\jasminewd2\index.js:108:15
at new ManagedPromise (C:\Users\koanand\Documents\Protractor\ASR\node_modules\selenium-webdriver\lib\promise.js:1077:7)
at ControlFlow.promise (C:\Users\koanand\Documents\Protractor\ASR\node_modules\selenium-webdriver\lib\promise.js:2505:12)
at schedulerExecute (C:\Users\koanan
d\Docume

Answer 1

Use BeforeAll() in each spec file & write whatever you want to execute before each spec starts

Answer 2

May following link help you to clear your doubts for onPrepare and what to use in pace of it.
OnPrepare function in Protractor