Error: Cannot find module 'tap'

Got this error;

> weather-app@1.0.0 test C:\Users\Ofirs\Desktop\n-4-11-chaining
> mocha **/*.test.js

module.js:540
    throw err;
    ^

Error: Cannot find module 'tap'
    at Function.Module._resolveFilename (module.js:538:15)

when trying to run mocha by "npm run test-watch" here is my package.json file:

{
"name": "weather-app",
"version": "1.0.0",
"description": "",
"main": "test.js",
"scripts": {
    "test": "mocha **/*.test.js",
    "test-watch": "nodemon --exec \"npm test\""
},
"author": "",
"license": "ISC",
"dependencies": {
    "request": "^2.83.0",
    "yargs": "^4.8.1"
},
"devDependencies": {
    "chai": "^4.1.2",
    "mocha": "^4.1.0",
    "supertest": "^3.0.0"
}
}

please help me to find the problem. peace