Program a test to check for libraries in the "package.json" type "@types/..." that are in the wrong place. Is it possible?

Question

I’ve taken several times package.json libraries "@types/..." in "dependencies" instead of "devDependencies".

It is that they were installed without adding the parameter -D during the yarn add. Mistakes happen and it’s completely normal.

Some devs end up installing the dependency incorrectly and it gets annoying to keep requiring them over and over again to take this care.

VS Code here does not display any warning message when it is like this.

Then it would be possible to program a test in VS Code to check for dependencies "@types/..." who are in "dependencies" but they should be "devDependencies" using Typescript?

And if there are libraries that are in the wrong location, display an alert message on the PROBLEMS console of the VS Code type:

A biblioteca "@types/..." está no local incorreto no "package.json"! Ela deveria estar em "devDependencies" em vez de "dependencies".
A biblioteca "@types/..." está no local incorreto no "package.json"! Ela deveria estar em "devDependencies" em vez de "dependencies".

As the warning message needs to be in English, maybe it could look like this:

The library "@types / ..." is in the wrong location in "package.json"! It should be in "devDependencies" instead of "dependencies".
The library "@types / ..." is in the wrong location in "package.json"! It should be in "devDependencies" instead of "dependencies".

(I’m taking a chance on English! Forgive me! )

If devs do not take this care there can be multiple libraries on the application deploy without need. The deploy gets even slower because of this!

Is it possible to program this? Or does this already exist?

It makes sense to program this in VS Code in order to help devs take this kind of care?

Answer 1

If you have a script test in his package.json, can create another call pretest, which will always be run automatically before of test, or posttest, to be executed afterward of test (also automatically).

So whenever (before or after) a test is run, you can do this check.

In the package.json, something like that:

{
  "scripts": {
    "test": "<seu-script-de-testes>",
    "pretest": "node check-deps.js"
  },
  // ...
}

^{Note that we use pretest, which will execute the script check-deps.js before of the tests.}

And in the check-deps.js, can do something like this:

const { readFileSync } = require('fs');
const { join } = require('path');

const pkgPath = join(process.cwd(), 'package.json');
const { dependencies } = JSON.parse(readFileSync(pkgPath, 'utf8'));

if (typeof dependencies !== 'object') {
  process.exit(0);
}

let warned = false;
for (const depName of Object.keys(dependencies)) {
  if (depName.startsWith('@types/')) {
    if (!warned) {
      warned = true;
    }

    console.error(
      `Dependência "${depName}" deveria estar no campo \`devDependencies\`, e não \`dependencies\`.`
    );
  }
}

process.exit(warned ? 1 : 0);

If you want to do something more connected to Vscode, you can try create an extension.

Answer 2

We believe that there is no concrete possibility to do this, because let us think about the following case. Our library reference archive is package.json, right? And in it, it contains various properties like:

author:...
license:...
version:...

So, logically, the right one would be something like, locate the file package.json, access the file, search dependencies if there is any @types, if yes, check if there is devDependencies, if available, launch a Warning telling it to install the typesetting library in development mode. I guess I’d have to do something like streams, that we can access and etc...