Cannot find module 'chai' immediately after setup

[jbcpollak]

I followed the setup instructions (clone then npm install), and when I run gulp, everything starts fine. But if I run npm test, I get this error:

module.js:338
    throw err;
    ^

Error: Cannot find module 'chai'
    at Function.Module._resolveFilename (module.js:336:15)
    at Function.require.resolve (module.js:388:19)

I see karma-chai is a dependency, and it is installed in node_modules.

I am using node v4.1.2 and npm 3.3.6.

[fesor]

The reason is that chai module listed in karma-chai as peer dependency.

With NPM3 you'll get this warnings:

npm WARN peerDependencies The peer dependency chai@* included from karma-chai will no
npm WARN peerDependencies longer be automatically installed to fulfill the peerDependency
npm WARN peerDependencies in npm 3+. Your application will need to depend on it explicitly.

So what you need to do is just install chai locally for your project:

npm install --save chai