mocha: Cannot find module 'tap', but tap isn't listed as a dependency

It’s something I run into as well. I think that 's because you run a test from your node_modules. You can prevent running test from node_modules by doing mocha \"./{,!(node_modules)/**/}*.test.js\" (uf you want to run *.test.js files

Meh, I don’t find it difficult to have an editor window with two tabs showing both code and corresponding test in different directories. I usually organize mine like this:

| -- myproj
     |-- /lib
         {source code}
     |-- /test
         |-- /unit
             |-- /fixtures
         |-- /e2e
             |-- /fixtures

But it’s a rather trivial cmdline change to incorporate your style…

$ NODE_ENV=test mocha --require @babel/register 'lib/**/*.spec.js' 'test/**/*.js'

try this:

npm la tap

you can figure out which dep depends on tap with that command