如何使用 JS 脚本在同一个文件中运行 mocha

Question

Is it possible to have the JS code and the mocha tests in the same file? The purpose will be to have both the implementation and the tests in the same file when you just want to play with something, learn JS, prepare for an interview, etc.

The file will be executed in VSCode using Debug (F5).

function increment(n) {
return n + 1;
}

mocha.setup("bdd");
const { assert } = chai;

describe('Array', function () {
    describe('#indexOf()', function () {
        it('should increment', function () {
            assert.equal(increment(1), 2);
        });
    });
});

mocha.run();

Trying to run this example which is how you run mocha tests in browser, I get an error "mocha is not defined"

I ran "npm install --save-dev mocha" and "npm install --save-dev chai". The file is test1.js. In app.js I have "require("./test1")". The launch configuration is:

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Launch Program",
            "program": "${workspaceFolder}/app.js",
            "request": "launch",
            "skipFiles": [
                "<node_internals>/**"
            ],
            "type": "pwa-node"
        }
    ]
}

Answer 1

After more googling I found the solution, your Debug launch.json file have to have the below configuration. Basically the program you need to launch is "${workspaceFolder}/node_modules/mocha/bin/_mocha".

You do not need any mocha commands in your JS file: mocha.setup("bdd"); mocha.run();

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Mocha Tests",
            "type": "pwa-node",
            "request": "launch",
            "program": "${workspaceFolder}/node_modules/mocha/bin/_mocha",
            "args": [
                "-u",
                "bdd",
                "--timeout",
                "999999",
                "--colors",
                "${workspaceFolder}/thon-ly-40-questions"
            ],
            "skipFiles": [
                "<node_internals>/**"
            ],
        },
    ]
}