How to set variable in unit test of task

I try to set variables before run a task in a unit test

Environment

azure-pipelines-task-lib version: 2.9.3

Issue Description

I tried to set variables in the unit test with

import * as fs from 'fs';
import * as path from 'path';
import { TaskMockRunner } from 'azure-pipelines-task-lib/mock-run';
import { TaskLibAnswers } from 'azure-pipelines-task-lib/mock-answer';

const task: TaskMockRunner = new TaskMockRunner(taskPath);
task.setInput('excelFilePath', excelFilePath);
task.setVariableName('Build.BinariesDirectory', __dirname);
task.setVariableName('Product.Version', '0.1.0');

// Mock answer for excel file path
let answers: TaskLibAnswers = <TaskLibAnswers>{
	"checkPath": {
		[excelFilePath]: fs.existsSync(excelFilePath)
	}
};
task.setAnswers(answers);

task.run();

And in the task i get variables in run function with :

import { TaskResult, VariableInfo, getPathInput, setResult, getVariables } from 'azure-pipelines-task-lib/task';
...
let variables: VariableInfo[] = getVariables();

but the array is always empty

Expected behaviour

The variables array should contains ‘Build.BinariesDirectory’ and ‘Product.Version’

Actual behaviour

The array is always empty I also tried with:

task.setVariableName('BUILD_BINARIESDIRECTORY', __dirname);
task.setVariableName('PRODUCT_VERSION', '0.1.0');

or

process.env['Build.BinariesDirectory'] = __dirname;
process.env['Product.Version'] = '0.1.0';

or

process.env['BUILD_BINARIESDIRECTORY'] = __dirname;
process.env['PRODUCT_VERSION'] = '0.1.0';

[jtpetty]

ok, I think I understand now. I have a work around for you. The issue appears that when you use a method from task-lib in your unit test, it does some initialization and then the mocking for task.setInput no longer works.

Here is a work around to set the variables and have getVariables() return the right thing:

process.env['PRODUCT_VERSION'] = '0.1.0';
process.env['BUILD_BINARIESDIRECTORY'] = __dirname;
process.env['VSTS_PUBLIC_VARIABLES'] = '["Product.Version","Build.BinariesDirectory"]';

[CodeTroopers]

Yes, thanks for your help