diff options
Diffstat (limited to 'tools/node_modules/eslint/lib/rules/comma-style.js')
| -rw-r--r-- | tools/node_modules/eslint/lib/rules/comma-style.js | 299 |
1 files changed, 299 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/rules/comma-style.js b/tools/node_modules/eslint/lib/rules/comma-style.js new file mode 100644 index 0000000000..4c65338a44 --- /dev/null +++ b/tools/node_modules/eslint/lib/rules/comma-style.js @@ -0,0 +1,299 @@ +/** + * @fileoverview Comma style - enforces comma styles of two types: last and first + * @author Vignesh Anand aka vegetableman + */ + +"use strict"; + +const astUtils = require("../ast-utils"); + +//------------------------------------------------------------------------------ +// Rule Definition +//------------------------------------------------------------------------------ + +module.exports = { + meta: { + docs: { + description: "enforce consistent comma style", + category: "Stylistic Issues", + recommended: false + }, + fixable: "code", + schema: [ + { + enum: ["first", "last"] + }, + { + type: "object", + properties: { + exceptions: { + type: "object", + additionalProperties: { + type: "boolean" + } + } + }, + additionalProperties: false + } + ] + }, + + create(context) { + const style = context.options[0] || "last", + sourceCode = context.getSourceCode(); + const exceptions = { + ArrayPattern: true, + ArrowFunctionExpression: true, + CallExpression: true, + FunctionDeclaration: true, + FunctionExpression: true, + ImportDeclaration: true, + ObjectPattern: true + }; + + if (context.options.length === 2 && context.options[1].hasOwnProperty("exceptions")) { + const keys = Object.keys(context.options[1].exceptions); + + for (let i = 0; i < keys.length; i++) { + exceptions[keys[i]] = context.options[1].exceptions[keys[i]]; + } + } + + //-------------------------------------------------------------------------- + // Helpers + //-------------------------------------------------------------------------- + + /** + * Modified text based on the style + * @param {string} styleType Style type + * @param {string} text Source code text + * @returns {string} modified text + * @private + */ + function getReplacedText(styleType, text) { + switch (styleType) { + case "between": + return `,${text.replace("\n", "")}`; + + case "first": + return `${text},`; + + case "last": + return `,${text}`; + + default: + return ""; + } + } + + /** + * Determines the fixer function for a given style. + * @param {string} styleType comma style + * @param {ASTNode} previousItemToken The token to check. + * @param {ASTNode} commaToken The token to check. + * @param {ASTNode} currentItemToken The token to check. + * @returns {Function} Fixer function + * @private + */ + function getFixerFunction(styleType, previousItemToken, commaToken, currentItemToken) { + const text = + sourceCode.text.slice(previousItemToken.range[1], commaToken.range[0]) + + sourceCode.text.slice(commaToken.range[1], currentItemToken.range[0]); + const range = [previousItemToken.range[1], currentItemToken.range[0]]; + + return function(fixer) { + return fixer.replaceTextRange(range, getReplacedText(styleType, text)); + }; + } + + /** + * Validates the spacing around single items in lists. + * @param {Token} previousItemToken The last token from the previous item. + * @param {Token} commaToken The token representing the comma. + * @param {Token} currentItemToken The first token of the current item. + * @param {Token} reportItem The item to use when reporting an error. + * @returns {void} + * @private + */ + function validateCommaItemSpacing(previousItemToken, commaToken, currentItemToken, reportItem) { + + // if single line + if (astUtils.isTokenOnSameLine(commaToken, currentItemToken) && + astUtils.isTokenOnSameLine(previousItemToken, commaToken)) { + + // do nothing. + + } else if (!astUtils.isTokenOnSameLine(commaToken, currentItemToken) && + !astUtils.isTokenOnSameLine(previousItemToken, commaToken)) { + + // lone comma + context.report({ + node: reportItem, + loc: { + line: commaToken.loc.end.line, + column: commaToken.loc.start.column + }, + message: "Bad line breaking before and after ','.", + fix: getFixerFunction("between", previousItemToken, commaToken, currentItemToken) + }); + + } else if (style === "first" && !astUtils.isTokenOnSameLine(commaToken, currentItemToken)) { + + context.report({ + node: reportItem, + message: "',' should be placed first.", + fix: getFixerFunction(style, previousItemToken, commaToken, currentItemToken) + }); + + } else if (style === "last" && astUtils.isTokenOnSameLine(commaToken, currentItemToken)) { + + context.report({ + node: reportItem, + loc: { + line: commaToken.loc.end.line, + column: commaToken.loc.end.column + }, + message: "',' should be placed last.", + fix: getFixerFunction(style, previousItemToken, commaToken, currentItemToken) + }); + } + } + + /** + * Checks the comma placement with regards to a declaration/property/element + * @param {ASTNode} node The binary expression node to check + * @param {string} property The property of the node containing child nodes. + * @private + * @returns {void} + */ + function validateComma(node, property) { + const items = node[property], + arrayLiteral = (node.type === "ArrayExpression" || node.type === "ArrayPattern"); + + if (items.length > 1 || arrayLiteral) { + + // seed as opening [ + let previousItemToken = sourceCode.getFirstToken(node); + + items.forEach(item => { + const commaToken = item ? sourceCode.getTokenBefore(item) : previousItemToken, + currentItemToken = item ? sourceCode.getFirstToken(item) : sourceCode.getTokenAfter(commaToken), + reportItem = item || currentItemToken, + tokenBeforeComma = sourceCode.getTokenBefore(commaToken); + + // Check if previous token is wrapped in parentheses + if (tokenBeforeComma && astUtils.isClosingParenToken(tokenBeforeComma)) { + previousItemToken = tokenBeforeComma; + } + + /* + * This works by comparing three token locations: + * - previousItemToken is the last token of the previous item + * - commaToken is the location of the comma before the current item + * - currentItemToken is the first token of the current item + * + * These values get switched around if item is undefined. + * previousItemToken will refer to the last token not belonging + * to the current item, which could be a comma or an opening + * square bracket. currentItemToken could be a comma. + * + * All comparisons are done based on these tokens directly, so + * they are always valid regardless of an undefined item. + */ + if (astUtils.isCommaToken(commaToken)) { + validateCommaItemSpacing(previousItemToken, commaToken, + currentItemToken, reportItem); + } + + if (item) { + const tokenAfterItem = sourceCode.getTokenAfter(item, astUtils.isNotClosingParenToken); + + previousItemToken = tokenAfterItem + ? sourceCode.getTokenBefore(tokenAfterItem) + : sourceCode.ast.tokens[sourceCode.ast.tokens.length - 1]; + } + }); + + /* + * Special case for array literals that have empty last items, such + * as [ 1, 2, ]. These arrays only have two items show up in the + * AST, so we need to look at the token to verify that there's no + * dangling comma. + */ + if (arrayLiteral) { + + const lastToken = sourceCode.getLastToken(node), + nextToLastToken = sourceCode.getTokenBefore(lastToken); + + if (astUtils.isCommaToken(nextToLastToken)) { + validateCommaItemSpacing( + sourceCode.getTokenBefore(nextToLastToken), + nextToLastToken, + lastToken, + lastToken + ); + } + } + } + } + + //-------------------------------------------------------------------------- + // Public + //-------------------------------------------------------------------------- + + const nodes = {}; + + if (!exceptions.VariableDeclaration) { + nodes.VariableDeclaration = function(node) { + validateComma(node, "declarations"); + }; + } + if (!exceptions.ObjectExpression) { + nodes.ObjectExpression = function(node) { + validateComma(node, "properties"); + }; + } + if (!exceptions.ObjectPattern) { + nodes.ObjectPattern = function(node) { + validateComma(node, "properties"); + }; + } + if (!exceptions.ArrayExpression) { + nodes.ArrayExpression = function(node) { + validateComma(node, "elements"); + }; + } + if (!exceptions.ArrayPattern) { + nodes.ArrayPattern = function(node) { + validateComma(node, "elements"); + }; + } + if (!exceptions.FunctionDeclaration) { + nodes.FunctionDeclaration = function(node) { + validateComma(node, "params"); + }; + } + if (!exceptions.FunctionExpression) { + nodes.FunctionExpression = function(node) { + validateComma(node, "params"); + }; + } + if (!exceptions.ArrowFunctionExpression) { + nodes.ArrowFunctionExpression = function(node) { + validateComma(node, "params"); + }; + } + if (!exceptions.CallExpression) { + nodes.CallExpression = function(node) { + validateComma(node, "arguments"); + }; + } + if (!exceptions.ImportDeclaration) { + nodes.ImportDeclaration = function(node) { + validateComma(node, "specifiers"); + }; + } + + return nodes; + } +}; |