[d565449] | 1 | /**
|
---|
| 2 | * @fileoverview Disallow construction of dense arrays using the Array constructor
|
---|
| 3 | * @author Matt DuVall <http://www.mattduvall.com/>
|
---|
| 4 | */
|
---|
| 5 |
|
---|
| 6 | "use strict";
|
---|
| 7 |
|
---|
| 8 | //------------------------------------------------------------------------------
|
---|
| 9 | // Requirements
|
---|
| 10 | //------------------------------------------------------------------------------
|
---|
| 11 |
|
---|
| 12 | const {
|
---|
| 13 | getVariableByName,
|
---|
| 14 | isClosingParenToken,
|
---|
| 15 | isOpeningParenToken,
|
---|
| 16 | isStartOfExpressionStatement,
|
---|
| 17 | needsPrecedingSemicolon
|
---|
| 18 | } = require("./utils/ast-utils");
|
---|
| 19 |
|
---|
| 20 | //------------------------------------------------------------------------------
|
---|
| 21 | // Rule Definition
|
---|
| 22 | //------------------------------------------------------------------------------
|
---|
| 23 |
|
---|
| 24 | /** @type {import('../shared/types').Rule} */
|
---|
| 25 | module.exports = {
|
---|
| 26 | meta: {
|
---|
| 27 | type: "suggestion",
|
---|
| 28 |
|
---|
| 29 | docs: {
|
---|
| 30 | description: "Disallow `Array` constructors",
|
---|
| 31 | recommended: false,
|
---|
| 32 | url: "https://eslint.org/docs/latest/rules/no-array-constructor"
|
---|
| 33 | },
|
---|
| 34 |
|
---|
| 35 | hasSuggestions: true,
|
---|
| 36 |
|
---|
| 37 | schema: [],
|
---|
| 38 |
|
---|
| 39 | messages: {
|
---|
| 40 | preferLiteral: "The array literal notation [] is preferable.",
|
---|
| 41 | useLiteral: "Replace with an array literal.",
|
---|
| 42 | useLiteralAfterSemicolon: "Replace with an array literal, add preceding semicolon."
|
---|
| 43 | }
|
---|
| 44 | },
|
---|
| 45 |
|
---|
| 46 | create(context) {
|
---|
| 47 |
|
---|
| 48 | const sourceCode = context.sourceCode;
|
---|
| 49 |
|
---|
| 50 | /**
|
---|
| 51 | * Gets the text between the calling parentheses of a CallExpression or NewExpression.
|
---|
| 52 | * @param {ASTNode} node A CallExpression or NewExpression node.
|
---|
| 53 | * @returns {string} The text between the calling parentheses, or an empty string if there are none.
|
---|
| 54 | */
|
---|
| 55 | function getArgumentsText(node) {
|
---|
| 56 | const lastToken = sourceCode.getLastToken(node);
|
---|
| 57 |
|
---|
| 58 | if (!isClosingParenToken(lastToken)) {
|
---|
| 59 | return "";
|
---|
| 60 | }
|
---|
| 61 |
|
---|
| 62 | let firstToken = node.callee;
|
---|
| 63 |
|
---|
| 64 | do {
|
---|
| 65 | firstToken = sourceCode.getTokenAfter(firstToken);
|
---|
| 66 | if (!firstToken || firstToken === lastToken) {
|
---|
| 67 | return "";
|
---|
| 68 | }
|
---|
| 69 | } while (!isOpeningParenToken(firstToken));
|
---|
| 70 |
|
---|
| 71 | return sourceCode.text.slice(firstToken.range[1], lastToken.range[0]);
|
---|
| 72 | }
|
---|
| 73 |
|
---|
| 74 | /**
|
---|
| 75 | * Disallow construction of dense arrays using the Array constructor
|
---|
| 76 | * @param {ASTNode} node node to evaluate
|
---|
| 77 | * @returns {void}
|
---|
| 78 | * @private
|
---|
| 79 | */
|
---|
| 80 | function check(node) {
|
---|
| 81 | if (
|
---|
| 82 | node.callee.type !== "Identifier" ||
|
---|
| 83 | node.callee.name !== "Array" ||
|
---|
| 84 | node.arguments.length === 1 &&
|
---|
| 85 | node.arguments[0].type !== "SpreadElement") {
|
---|
| 86 | return;
|
---|
| 87 | }
|
---|
| 88 |
|
---|
| 89 | const variable = getVariableByName(sourceCode.getScope(node), "Array");
|
---|
| 90 |
|
---|
| 91 | /*
|
---|
| 92 | * Check if `Array` is a predefined global variable: predefined globals have no declarations,
|
---|
| 93 | * meaning that the `identifiers` list of the variable object is empty.
|
---|
| 94 | */
|
---|
| 95 | if (variable && variable.identifiers.length === 0) {
|
---|
| 96 | const argsText = getArgumentsText(node);
|
---|
| 97 | let fixText;
|
---|
| 98 | let messageId;
|
---|
| 99 |
|
---|
| 100 | /*
|
---|
| 101 | * Check if the suggested change should include a preceding semicolon or not.
|
---|
| 102 | * Due to JavaScript's ASI rules, a missing semicolon may be inserted automatically
|
---|
| 103 | * before an expression like `Array()` or `new Array()`, but not when the expression
|
---|
| 104 | * is changed into an array literal like `[]`.
|
---|
| 105 | */
|
---|
| 106 | if (isStartOfExpressionStatement(node) && needsPrecedingSemicolon(sourceCode, node)) {
|
---|
| 107 | fixText = `;[${argsText}]`;
|
---|
| 108 | messageId = "useLiteralAfterSemicolon";
|
---|
| 109 | } else {
|
---|
| 110 | fixText = `[${argsText}]`;
|
---|
| 111 | messageId = "useLiteral";
|
---|
| 112 | }
|
---|
| 113 |
|
---|
| 114 | context.report({
|
---|
| 115 | node,
|
---|
| 116 | messageId: "preferLiteral",
|
---|
| 117 | suggest: [
|
---|
| 118 | {
|
---|
| 119 | messageId,
|
---|
| 120 | fix: fixer => fixer.replaceText(node, fixText)
|
---|
| 121 | }
|
---|
| 122 | ]
|
---|
| 123 | });
|
---|
| 124 | }
|
---|
| 125 | }
|
---|
| 126 |
|
---|
| 127 | return {
|
---|
| 128 | CallExpression: check,
|
---|
| 129 | NewExpression: check
|
---|
| 130 | };
|
---|
| 131 |
|
---|
| 132 | }
|
---|
| 133 | };
|
---|