121 lines
3.0 KiB
JavaScript
121 lines
3.0 KiB
JavaScript
'use strict';
|
|
const {
|
|
not,
|
|
methodCallSelector,
|
|
callExpressionSelector,
|
|
} = require('./selectors/index.js');
|
|
|
|
const ERROR_MESSAGE_ID = 'error';
|
|
const SUGGESTION_REPLACE_MESSAGE_ID = 'replace';
|
|
const SUGGESTION_REMOVE_MESSAGE_ID = 'remove';
|
|
const messages = {
|
|
[ERROR_MESSAGE_ID]: 'Use `undefined` instead of `null`.',
|
|
[SUGGESTION_REPLACE_MESSAGE_ID]: 'Replace `null` with `undefined`.',
|
|
[SUGGESTION_REMOVE_MESSAGE_ID]: 'Remove `null`.',
|
|
};
|
|
|
|
const selector = [
|
|
'Literal',
|
|
'[raw="null"]',
|
|
not([
|
|
// `Object.create(null)`, `Object.create(null, foo)`
|
|
`${methodCallSelector({object: 'Object', method: 'create', minimumArguments: 1, maximumArguments: 2})} > .arguments:first-child`,
|
|
// `useRef(null)`
|
|
`${callExpressionSelector({name: 'useRef', argumentsLength: 1})} > .arguments:first-child`,
|
|
// `React.useRef(null)`
|
|
`${methodCallSelector({object: 'React', method: 'useRef', argumentsLength: 1})} > .arguments:first-child`,
|
|
// `foo.insertBefore(bar, null)`
|
|
`${methodCallSelector({method: 'insertBefore', argumentsLength: 2})}[arguments.0.type!="SpreadElement"] > .arguments:nth-child(2)`,
|
|
]),
|
|
].join('');
|
|
|
|
const isLooseEqual = node => node.type === 'BinaryExpression' && ['==', '!='].includes(node.operator);
|
|
const isStrictEqual = node => node.type === 'BinaryExpression' && ['===', '!=='].includes(node.operator);
|
|
|
|
/** @param {import('eslint').Rule.RuleContext} context */
|
|
const create = context => {
|
|
const {checkStrictEquality} = {
|
|
checkStrictEquality: false,
|
|
...context.options[0],
|
|
};
|
|
|
|
return {
|
|
[selector](node) {
|
|
const {parent} = node;
|
|
if (!checkStrictEquality && isStrictEqual(parent)) {
|
|
return;
|
|
}
|
|
|
|
const problem = {
|
|
node,
|
|
messageId: ERROR_MESSAGE_ID,
|
|
};
|
|
|
|
const useUndefinedFix = fixer => fixer.replaceText(node, 'undefined');
|
|
|
|
if (isLooseEqual(parent)) {
|
|
problem.fix = useUndefinedFix;
|
|
return problem;
|
|
}
|
|
|
|
const useUndefinedSuggestion = {
|
|
messageId: SUGGESTION_REPLACE_MESSAGE_ID,
|
|
fix: useUndefinedFix,
|
|
};
|
|
|
|
if (parent.type === 'ReturnStatement' && parent.argument === node) {
|
|
problem.suggest = [
|
|
{
|
|
messageId: SUGGESTION_REMOVE_MESSAGE_ID,
|
|
fix: fixer => fixer.remove(node),
|
|
},
|
|
useUndefinedSuggestion,
|
|
];
|
|
return problem;
|
|
}
|
|
|
|
if (parent.type === 'VariableDeclarator' && parent.init === node && parent.parent.kind !== 'const') {
|
|
problem.suggest = [
|
|
{
|
|
messageId: SUGGESTION_REMOVE_MESSAGE_ID,
|
|
fix: fixer => fixer.removeRange([parent.id.range[1], node.range[1]]),
|
|
},
|
|
useUndefinedSuggestion,
|
|
];
|
|
return problem;
|
|
}
|
|
|
|
problem.suggest = [useUndefinedSuggestion];
|
|
return problem;
|
|
},
|
|
};
|
|
};
|
|
|
|
const schema = [
|
|
{
|
|
type: 'object',
|
|
additionalProperties: false,
|
|
properties: {
|
|
checkStrictEquality: {
|
|
type: 'boolean',
|
|
default: false,
|
|
},
|
|
},
|
|
},
|
|
];
|
|
|
|
/** @type {import('eslint').Rule.RuleModule} */
|
|
module.exports = {
|
|
create,
|
|
meta: {
|
|
type: 'suggestion',
|
|
docs: {
|
|
description: 'Disallow the use of the `null` literal.',
|
|
},
|
|
fixable: 'code',
|
|
hasSuggestions: true,
|
|
schema,
|
|
messages,
|
|
},
|
|
};
|