eslint-plugin-unicorn/rules/prefer-regexp-test.js

More than 100 powerful ESLint rules

import {isParenthesized, getStaticValue} from '@eslint-community/eslint-utils';
import {checkVueTemplate} from './utils/rule.js';
import {isRegexLiteral, isNewExpression, isMethodCall} from './ast/index.js';
import {isBooleanNode, shouldAddParenthesesToMemberExpressionObject} from './utils/index.js';

const REGEXP_EXEC = 'regexp-exec';
const STRING_MATCH = 'string-match';
const SUGGESTION = 'suggestion';
const messages = {
	[REGEXP_EXEC]: 'Prefer `.test(…)` over `.exec(…)`.',
	[STRING_MATCH]: 'Prefer `RegExp#test(…)` over `String#match(…)`.',
	[SUGGESTION]: 'Switch to `RegExp#test(…)`.',
};

const cases = [
	{
		type: REGEXP_EXEC,
		test: node => isMethodCall(node, {
			method: 'exec',
			argumentsLength: 1,
			optionalCall: false,
			optionalMember: false,
		}),
		getNodes: node => ({
			stringNode: node.arguments[0],
			methodNode: node.callee.property,
			regexpNode: node.callee.object,
		}),
		fix: (fixer, {methodNode}) => fixer.replaceText(methodNode, 'test'),
	},
	{
		type: STRING_MATCH,
		test: node => isMethodCall(node, {
			method: 'match',
			argumentsLength: 1,
			optionalCall: false,
			optionalMember: false,
		}),
		getNodes: node => ({
			stringNode: node.callee.object,
			methodNode: node.callee.property,
			regexpNode: node.arguments[0],
		}),
		* fix(fixer, {stringNode, methodNode, regexpNode}, sourceCode) {
			yield fixer.replaceText(methodNode, 'test');

			let stringText = sourceCode.getText(stringNode);
			if (
				!isParenthesized(regexpNode, sourceCode)
				// Only `SequenceExpression` need add parentheses
				&& stringNode.type === 'SequenceExpression'
			) {
				stringText = `(${stringText})`;
			}

			yield fixer.replaceText(regexpNode, stringText);

			let regexpText = sourceCode.getText(regexpNode);
			if (
				!isParenthesized(stringNode, sourceCode)
				&& shouldAddParenthesesToMemberExpressionObject(regexpNode, sourceCode)
			) {
				regexpText = `(${regexpText})`;
			}

			// The nodes that pass `isBooleanNode` cannot have an ASI problem.

			yield fixer.replaceText(stringNode, regexpText);
		},
	},
];

const isRegExpNode = node => isRegexLiteral(node) || isNewExpression(node, {name: 'RegExp'});

const isRegExpWithoutGlobalFlag = (node, scope) => {
	if (isRegexLiteral(node)) {
		return !node.regex.flags.includes('g');
	}

	const staticResult = getStaticValue(node, scope);

	// Don't know if there is `g` flag
	if (!staticResult) {
		return false;
	}

	const {value} = staticResult;
	return (
		Object.prototype.toString.call(value) === '[object RegExp]'
		&& !value.global
	);
};

/** @param {import('eslint').Rule.RuleContext} context */
const create = context => ({
	* CallExpression(node) {
		if (!isBooleanNode(node)) {
			return;
		}

		for (const {type, test, getNodes, fix} of cases) {
			if (!test(node)) {
				continue;
			}

			const nodes = getNodes(node);
			const {methodNode, regexpNode} = nodes;

			if (regexpNode.type === 'Literal' && !regexpNode.regex) {
				continue;
			}

			const problem = {
				node: type === REGEXP_EXEC ? methodNode : node,
				messageId: type,
			};

			const {sourceCode} = context;
			const fixFunction = fixer => fix(fixer, nodes, sourceCode);

			if (
				isRegExpNode(regexpNode)
				|| isRegExpWithoutGlobalFlag(regexpNode, sourceCode.getScope(regexpNode))
			) {
				problem.fix = fixFunction;
			} else {
				problem.suggest = [
					{
						messageId: SUGGESTION,
						fix: fixFunction,
					},
				];
			}

			yield problem;
		}
	},
});

/** @type {import('eslint').Rule.RuleModule} */
const config = {
	create: checkVueTemplate(create),
	meta: {
		type: 'suggestion',
		docs: {
			description: 'Prefer `RegExp#test()` over `String#match()` and `RegExp#exec()`.',
			recommended: true,
		},
		fixable: 'code',
		hasSuggestions: true,
		messages,
	},
};

export default config;