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177 lines
6.7 KiB
177 lines
6.7 KiB
/** |
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* @fileoverview Rule to warn about using dot notation instead of square bracket notation when possible. |
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* @author Josh Perez |
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*/ |
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"use strict"; |
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//------------------------------------------------------------------------------ |
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// Requirements |
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//------------------------------------------------------------------------------ |
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const astUtils = require("./utils/ast-utils"); |
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const keywords = require("./utils/keywords"); |
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//------------------------------------------------------------------------------ |
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// Rule Definition |
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//------------------------------------------------------------------------------ |
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const validIdentifier = /^[a-zA-Z_$][a-zA-Z0-9_$]*$/u; |
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// `null` literal must be handled separately. |
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const literalTypesToCheck = new Set(["string", "boolean"]); |
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/** @type {import('../shared/types').Rule} */ |
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module.exports = { |
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meta: { |
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type: "suggestion", |
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docs: { |
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description: "Enforce dot notation whenever possible", |
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recommended: false, |
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url: "https://eslint.org/docs/rules/dot-notation" |
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}, |
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schema: [ |
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{ |
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type: "object", |
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properties: { |
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allowKeywords: { |
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type: "boolean", |
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default: true |
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}, |
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allowPattern: { |
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type: "string", |
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default: "" |
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} |
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}, |
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additionalProperties: false |
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} |
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], |
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fixable: "code", |
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messages: { |
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useDot: "[{{key}}] is better written in dot notation.", |
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useBrackets: ".{{key}} is a syntax error." |
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} |
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}, |
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create(context) { |
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const options = context.options[0] || {}; |
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const allowKeywords = options.allowKeywords === void 0 || options.allowKeywords; |
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const sourceCode = context.getSourceCode(); |
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let allowPattern; |
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if (options.allowPattern) { |
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allowPattern = new RegExp(options.allowPattern, "u"); |
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} |
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/** |
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* Check if the property is valid dot notation |
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* @param {ASTNode} node The dot notation node |
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* @param {string} value Value which is to be checked |
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* @returns {void} |
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*/ |
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function checkComputedProperty(node, value) { |
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if ( |
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validIdentifier.test(value) && |
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(allowKeywords || !keywords.includes(String(value))) && |
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!(allowPattern && allowPattern.test(value)) |
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) { |
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const formattedValue = node.property.type === "Literal" ? JSON.stringify(value) : `\`${value}\``; |
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context.report({ |
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node: node.property, |
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messageId: "useDot", |
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data: { |
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key: formattedValue |
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}, |
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*fix(fixer) { |
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const leftBracket = sourceCode.getTokenAfter(node.object, astUtils.isOpeningBracketToken); |
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const rightBracket = sourceCode.getLastToken(node); |
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const nextToken = sourceCode.getTokenAfter(node); |
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// Don't perform any fixes if there are comments inside the brackets. |
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if (sourceCode.commentsExistBetween(leftBracket, rightBracket)) { |
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return; |
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} |
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// Replace the brackets by an identifier. |
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if (!node.optional) { |
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yield fixer.insertTextBefore( |
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leftBracket, |
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astUtils.isDecimalInteger(node.object) ? " ." : "." |
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); |
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} |
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yield fixer.replaceTextRange( |
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[leftBracket.range[0], rightBracket.range[1]], |
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value |
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); |
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// Insert a space after the property if it will be connected to the next token. |
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if ( |
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nextToken && |
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rightBracket.range[1] === nextToken.range[0] && |
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!astUtils.canTokensBeAdjacent(String(value), nextToken) |
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) { |
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yield fixer.insertTextAfter(node, " "); |
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} |
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} |
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}); |
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} |
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} |
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return { |
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MemberExpression(node) { |
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if ( |
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node.computed && |
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node.property.type === "Literal" && |
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(literalTypesToCheck.has(typeof node.property.value) || astUtils.isNullLiteral(node.property)) |
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) { |
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checkComputedProperty(node, node.property.value); |
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} |
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if ( |
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node.computed && |
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node.property.type === "TemplateLiteral" && |
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node.property.expressions.length === 0 |
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) { |
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checkComputedProperty(node, node.property.quasis[0].value.cooked); |
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} |
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if ( |
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!allowKeywords && |
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!node.computed && |
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node.property.type === "Identifier" && |
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keywords.includes(String(node.property.name)) |
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) { |
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context.report({ |
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node: node.property, |
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messageId: "useBrackets", |
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data: { |
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key: node.property.name |
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}, |
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*fix(fixer) { |
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const dotToken = sourceCode.getTokenBefore(node.property); |
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// A statement that starts with `let[` is parsed as a destructuring variable declaration, not a MemberExpression. |
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if (node.object.type === "Identifier" && node.object.name === "let" && !node.optional) { |
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return; |
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} |
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// Don't perform any fixes if there are comments between the dot and the property name. |
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if (sourceCode.commentsExistBetween(dotToken, node.property)) { |
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return; |
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} |
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// Replace the identifier to brackets. |
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if (!node.optional) { |
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yield fixer.remove(dotToken); |
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} |
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yield fixer.replaceText(node.property, `["${node.property.name}"]`); |
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} |
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}); |
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} |
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} |
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}; |
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} |
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};
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