feat(dx): warn if module is not registered but used

[manniL]

🆒 Your use case

When the composition API module is added to the dependencies but not registered, an unexpected fs error appears when using the plugin in the code.

TypeError: can't access property "native", fs.realpath is undefined

(FF)

webpack-internal:///./.nuxt/client.js:215 TypeError: Cannot read property 'native' of undefined
    at eval (webpack-internal:///./node_modules/fs-extra/lib/fs/index.js:107)
    at Object../node_modules/fs-extra/lib/fs/index.js (index.js:317)
    at __webpack_require__ (runtime.js:854)
    at fn (runtime.js:151)
    at eval (webpack-internal:///./node_modules/fs-extra/lib/index.js:6)
    at Object../node_modules/fs-extra/lib/index.js (index.js:329)
    at __webpack_require__ (runtime.js:854)
    at fn (runtime.js:151)
    at Object.eval (webpack-internal:///./node_modules/@nuxtjs/composition-api/lib/index.js:6)
    at eval (webpack-internal:///./node_modules/@nuxtjs/composition-api/lib/index.js:848)
_callee$ @ webpack-internal:///./.nuxt/client.js:215

(Chrome)

🆕 The solution you'd like
Instead of showing the cryptic error, give the hint that the module has to be registered

🔍 Alternatives you've considered
If this is too much effort, keep as is (possibly this issue will be help enough then when googling?).
This is mostly a DX upgrade that might help a small number of ppl.

[danielroe]

Having taken a look at this, there's very little that can be done if users haven't added the module to buildModules. But I've separated out the actual utilities so they can't be imported unless it's been setup correctly...