securityos/node_modules/eslint-plugin-unicorn/rules/prefer-logical-operator-ove...

160 lines
3.7 KiB
JavaScript

'use strict';
const {isParenthesized, getParenthesizedText} = require('./utils/parentheses.js');
const isSameReference = require('./utils/is-same-reference.js');
const shouldAddParenthesesToLogicalExpressionChild = require('./utils/should-add-parentheses-to-logical-expression-child.js');
const needsSemicolon = require('./utils/needs-semicolon.js');
const MESSAGE_ID_ERROR = 'prefer-logical-operator-over-ternary/error';
const MESSAGE_ID_SUGGESTION = 'prefer-logical-operator-over-ternary/suggestion';
const messages = {
[MESSAGE_ID_ERROR]: 'Prefer using a logical operator over a ternary.',
[MESSAGE_ID_SUGGESTION]: 'Switch to `{{operator}}` operator.',
};
function isSameNode(left, right, sourceCode) {
if (isSameReference(left, right)) {
return true;
}
if (left.type !== right.type) {
return false;
}
switch (left.type) {
case 'AwaitExpression': {
return isSameNode(left.argument, right.argument, sourceCode);
}
case 'LogicalExpression': {
return (
left.operator === right.operator
&& isSameNode(left.left, right.left, sourceCode)
&& isSameNode(left.right, right.right, sourceCode)
);
}
case 'UnaryExpression': {
return (
left.operator === right.operator
&& left.prefix === right.prefix
&& isSameNode(left.argument, right.argument, sourceCode)
);
}
case 'UpdateExpression': {
return false;
}
// No default
}
return sourceCode.getText(left) === sourceCode.getText(right);
}
function fix({
fixer,
sourceCode,
conditionalExpression,
left,
right,
operator,
}) {
let text = [left, right].map((node, index) => {
const isNodeParenthesized = isParenthesized(node, sourceCode);
let text = isNodeParenthesized ? getParenthesizedText(node, sourceCode) : sourceCode.getText(node);
if (
!isNodeParenthesized
&& shouldAddParenthesesToLogicalExpressionChild(node, {operator, property: index === 0 ? 'left' : 'right'})
) {
text = `(${text})`;
}
return text;
}).join(` ${operator} `);
// According to https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence#table
// There should be no cases need add parentheses when switching ternary to logical expression
// ASI
if (needsSemicolon(sourceCode.getTokenBefore(conditionalExpression), sourceCode, text)) {
text = `;${text}`;
}
return fixer.replaceText(conditionalExpression, text);
}
function getProblem({
sourceCode,
conditionalExpression,
left,
right,
}) {
return {
node: conditionalExpression,
messageId: MESSAGE_ID_ERROR,
suggest: ['??', '||'].map(operator => ({
messageId: MESSAGE_ID_SUGGESTION,
data: {operator},
fix: fixer => fix({
fixer,
sourceCode,
conditionalExpression,
left,
right,
operator,
}),
})),
};
}
/** @param {import('eslint').Rule.RuleContext} context */
const create = context => {
const sourceCode = context.getSourceCode();
return {
ConditionalExpression(conditionalExpression) {
const {test, consequent, alternate} = conditionalExpression;
// `foo ? foo : bar`
if (isSameNode(test, consequent, sourceCode)) {
return getProblem({
sourceCode,
conditionalExpression,
left: test,
right: alternate,
});
}
// `!bar ? foo : bar`
if (
test.type === 'UnaryExpression'
&& test.operator === '!'
&& test.prefix
&& isSameNode(test.argument, alternate, sourceCode)
) {
return getProblem({
sourceCode,
conditionalExpression,
left: test.argument,
right: consequent,
});
}
},
};
};
/** @type {import('eslint').Rule.RuleModule} */
module.exports = {
create,
meta: {
type: 'suggestion',
docs: {
description: 'Prefer using a logical operator over a ternary.',
},
hasSuggestions: true,
messages,
},
};