@putout/plugin-declare-undefined-variables

🐊Putout plugin adds ability to declare variable that was not defined before, including:

• is types: isFn, isString, isNumber, isObject, isBool, isUndefined, isSymbol and isNull;
• maybe: maybeArray, maybeFn, maybeEmptyArray;
• wrap: not,id, returns;
• fresh-import: freshImport, freshImportDefault;
• fixtures: readFixture(name);
• properties of Object;
• wraptile;
• fullstore;
• currify;
• pipe-io;
• pullout;
• simport;
• chalk;
• table;

Renamed to @putout/plugin-declare.

Install

npm i putout @putout/plugin-declare-undefined-variables -D

Add .putout.json with:

{
    "plugins": {
        "declare-undefined-variables": "on"
    }
}

Rules

Use options:

• ✅ dismiss for variables you don't want to declare;
• ✅ declarations to declare variables;

{
    "rules": {
        "declare-undefined-variables": ["on", {
            "declarations": {
                "hello": "import {hello} from 'world'"
            },
            "dismiss": [
                "assert",
                "entries",
                "parse",
                "stringify",
                "defineProperty",
                "isArray",
                "noop",
                "join",
                "keys",
                "values",
                "stopAll",
                "once",
                "putout",
                "simport"
            ]
        }]
    }
}

assign

❌ Example of incorrect code

const hello = 'world';
const object = {};

assign(object, {
    hello,
});

✅ Example of correct code

const hello = 'world';
const object = {};
const {assign} = Object;

assign(object, {
    hello,
});

keys

❌ Example of incorrect code

const hello = 'world';
const object = {};

const allKeys = keys(object);

✅ Example of correct code

const hello = 'world';
const object = {};
const {keys} = Object;

const allKeys = keys(object);

values

❌ Example of incorrect code

const object = {};
const allValues = values(object);

✅ Example of correct code

const {values} = Object;

const object = {};
const allValues = values(object);

isArray

❌ Example of incorrect code

isArray(array);

✅ Example of correct code

const {isArray} = Array;
isArray(array);

noop

❌ Example of incorrect code

noop();

✅ Example of correct code

const noop = () => {};
noop();

Types

❌ Example of incorrect code

if (isFn(fn))
    fn();

✅ Example of correct code

const isFn = (a) => typeof a === 'function';

if (isFn(fn))
    fn();

Maybe

❌ Example of incorrect code

const a = [
    ...maybeArray(b),
];

✅ Example of correct code

const {isArray} = Array;
const maybeArray = (a) => isArray(a) ? a : [a];

const a = [
    ...maybeArray(b),
];

License

MIT