Visual Code Run Build Task npm - node.js

Question

I'm using Visual Studio Code 1.13.0 on Windows 10.
I have the following build script in my package.json:
{
//omitted other props
"scripts": {
"build": "webpack"
}
}
I've installed webpack with npm install --global webpack, so it's installed globally.
The webpack.config.js is irrelevant for my question.
When I run npm run build in the terminal, everything works fine. But when I run the Visual Code Tasks: Run Build Task (ctrl+shift+b or ctrl+shift+p > Run Build Task), then I'm getting the following message in the output window:
'"npm run build"' is not recognized as an internal or external
command, operable program or batch file.
Why? (using npm version: 3.10.10)

Answer 1

You should create tasks.json file and specify build task with npm task runner as described here ctrl+shift+p > Configure Task Runner. In your case task.json file should looks something like that
{
// See https://go.microsoft.com/fwlink/?LinkId=733558
// for the documentation about the tasks.json format
"version": "0.1.0",
"command": "npm",
"isShellCommand": true,
"showOutput": "always",
"suppressTaskName": true,
"tasks": [
{
"isBuildCommand": true,
"taskName": "build",
"args": ["run", "build"]
}
]
}

Answer 2

tasks.json can be used for running multiple different tasks. This is #oleg-m's answer updated for version 2 of tasks.json:
{
// See https://go.microsoft.com/fwlink/?LinkId=733558
// for the documentation about the tasks.json format
"version": "2.0.0",
"tasks": [
{
"label": "build",
"type":"npm",
"script": "build",
"group": "build"
}
]
}