+++ /dev/null
-/**
- * @fileoverview A rule to control the use of single variable declarations.
- * @author Ian Christian Myers
- */
-
-"use strict";
-
-//------------------------------------------------------------------------------
-// Rule Definition
-//------------------------------------------------------------------------------
-
-module.exports = {
- meta: {
- type: "suggestion",
-
- docs: {
- description: "enforce variables to be declared either together or separately in functions",
- category: "Stylistic Issues",
- recommended: false,
- url: "https://eslint.org/docs/rules/one-var"
- },
-
- fixable: "code",
-
- schema: [
- {
- oneOf: [
- {
- enum: ["always", "never", "consecutive"]
- },
- {
- type: "object",
- properties: {
- separateRequires: {
- type: "boolean"
- },
- var: {
- enum: ["always", "never", "consecutive"]
- },
- let: {
- enum: ["always", "never", "consecutive"]
- },
- const: {
- enum: ["always", "never", "consecutive"]
- }
- },
- additionalProperties: false
- },
- {
- type: "object",
- properties: {
- initialized: {
- enum: ["always", "never", "consecutive"]
- },
- uninitialized: {
- enum: ["always", "never", "consecutive"]
- }
- },
- additionalProperties: false
- }
- ]
- }
- ]
- },
-
- create(context) {
- const MODE_ALWAYS = "always";
- const MODE_NEVER = "never";
- const MODE_CONSECUTIVE = "consecutive";
- const mode = context.options[0] || MODE_ALWAYS;
-
- const options = {};
-
- if (typeof mode === "string") { // simple options configuration with just a string
- options.var = { uninitialized: mode, initialized: mode };
- options.let = { uninitialized: mode, initialized: mode };
- options.const = { uninitialized: mode, initialized: mode };
- } else if (typeof mode === "object") { // options configuration is an object
- options.separateRequires = !!mode.separateRequires;
- options.var = { uninitialized: mode.var, initialized: mode.var };
- options.let = { uninitialized: mode.let, initialized: mode.let };
- options.const = { uninitialized: mode.const, initialized: mode.const };
- if (Object.prototype.hasOwnProperty.call(mode, "uninitialized")) {
- options.var.uninitialized = mode.uninitialized;
- options.let.uninitialized = mode.uninitialized;
- options.const.uninitialized = mode.uninitialized;
- }
- if (Object.prototype.hasOwnProperty.call(mode, "initialized")) {
- options.var.initialized = mode.initialized;
- options.let.initialized = mode.initialized;
- options.const.initialized = mode.initialized;
- }
- }
-
- const sourceCode = context.getSourceCode();
-
- //--------------------------------------------------------------------------
- // Helpers
- //--------------------------------------------------------------------------
-
- const functionStack = [];
- const blockStack = [];
-
- /**
- * Increments the blockStack counter.
- * @returns {void}
- * @private
- */
- function startBlock() {
- blockStack.push({
- let: { initialized: false, uninitialized: false },
- const: { initialized: false, uninitialized: false }
- });
- }
-
- /**
- * Increments the functionStack counter.
- * @returns {void}
- * @private
- */
- function startFunction() {
- functionStack.push({ initialized: false, uninitialized: false });
- startBlock();
- }
-
- /**
- * Decrements the blockStack counter.
- * @returns {void}
- * @private
- */
- function endBlock() {
- blockStack.pop();
- }
-
- /**
- * Decrements the functionStack counter.
- * @returns {void}
- * @private
- */
- function endFunction() {
- functionStack.pop();
- endBlock();
- }
-
- /**
- * Check if a variable declaration is a require.
- * @param {ASTNode} decl variable declaration Node
- * @returns {bool} if decl is a require, return true; else return false.
- * @private
- */
- function isRequire(decl) {
- return decl.init && decl.init.type === "CallExpression" && decl.init.callee.name === "require";
- }
-
- /**
- * Records whether initialized/uninitialized/required variables are defined in current scope.
- * @param {string} statementType node.kind, one of: "var", "let", or "const"
- * @param {ASTNode[]} declarations List of declarations
- * @param {Object} currentScope The scope being investigated
- * @returns {void}
- * @private
- */
- function recordTypes(statementType, declarations, currentScope) {
- for (let i = 0; i < declarations.length; i++) {
- if (declarations[i].init === null) {
- if (options[statementType] && options[statementType].uninitialized === MODE_ALWAYS) {
- currentScope.uninitialized = true;
- }
- } else {
- if (options[statementType] && options[statementType].initialized === MODE_ALWAYS) {
- if (options.separateRequires && isRequire(declarations[i])) {
- currentScope.required = true;
- } else {
- currentScope.initialized = true;
- }
- }
- }
- }
- }
-
- /**
- * Determines the current scope (function or block)
- * @param {string} statementType node.kind, one of: "var", "let", or "const"
- * @returns {Object} The scope associated with statementType
- */
- function getCurrentScope(statementType) {
- let currentScope;
-
- if (statementType === "var") {
- currentScope = functionStack[functionStack.length - 1];
- } else if (statementType === "let") {
- currentScope = blockStack[blockStack.length - 1].let;
- } else if (statementType === "const") {
- currentScope = blockStack[blockStack.length - 1].const;
- }
- return currentScope;
- }
-
- /**
- * Counts the number of initialized and uninitialized declarations in a list of declarations
- * @param {ASTNode[]} declarations List of declarations
- * @returns {Object} Counts of 'uninitialized' and 'initialized' declarations
- * @private
- */
- function countDeclarations(declarations) {
- const counts = { uninitialized: 0, initialized: 0 };
-
- for (let i = 0; i < declarations.length; i++) {
- if (declarations[i].init === null) {
- counts.uninitialized++;
- } else {
- counts.initialized++;
- }
- }
- return counts;
- }
-
- /**
- * Determines if there is more than one var statement in the current scope.
- * @param {string} statementType node.kind, one of: "var", "let", or "const"
- * @param {ASTNode[]} declarations List of declarations
- * @returns {boolean} Returns true if it is the first var declaration, false if not.
- * @private
- */
- function hasOnlyOneStatement(statementType, declarations) {
-
- const declarationCounts = countDeclarations(declarations);
- const currentOptions = options[statementType] || {};
- const currentScope = getCurrentScope(statementType);
- const hasRequires = declarations.some(isRequire);
-
- if (currentOptions.uninitialized === MODE_ALWAYS && currentOptions.initialized === MODE_ALWAYS) {
- if (currentScope.uninitialized || currentScope.initialized) {
- if (!hasRequires) {
- return false;
- }
- }
- }
-
- if (declarationCounts.uninitialized > 0) {
- if (currentOptions.uninitialized === MODE_ALWAYS && currentScope.uninitialized) {
- return false;
- }
- }
- if (declarationCounts.initialized > 0) {
- if (currentOptions.initialized === MODE_ALWAYS && currentScope.initialized) {
- if (!hasRequires) {
- return false;
- }
- }
- }
- if (currentScope.required && hasRequires) {
- return false;
- }
- recordTypes(statementType, declarations, currentScope);
- return true;
- }
-
- /**
- * Fixer to join VariableDeclaration's into a single declaration
- * @param {VariableDeclarator[]} declarations The `VariableDeclaration` to join
- * @returns {Function} The fixer function
- */
- function joinDeclarations(declarations) {
- const declaration = declarations[0];
- const body = Array.isArray(declaration.parent.parent.body) ? declaration.parent.parent.body : [];
- const currentIndex = body.findIndex(node => node.range[0] === declaration.parent.range[0]);
- const previousNode = body[currentIndex - 1];
-
- return fixer => {
- const type = sourceCode.getTokenBefore(declaration);
- const prevSemi = sourceCode.getTokenBefore(type);
- const res = [];
-
- if (previousNode && previousNode.kind === sourceCode.getText(type)) {
- if (prevSemi.value === ";") {
- res.push(fixer.replaceText(prevSemi, ","));
- } else {
- res.push(fixer.insertTextAfter(prevSemi, ","));
- }
- res.push(fixer.replaceText(type, ""));
- }
-
- return res;
- };
- }
-
- /**
- * Fixer to split a VariableDeclaration into individual declarations
- * @param {VariableDeclaration} declaration The `VariableDeclaration` to split
- * @returns {Function} The fixer function
- */
- function splitDeclarations(declaration) {
- return fixer => declaration.declarations.map(declarator => {
- const tokenAfterDeclarator = sourceCode.getTokenAfter(declarator);
-
- if (tokenAfterDeclarator === null) {
- return null;
- }
-
- const afterComma = sourceCode.getTokenAfter(tokenAfterDeclarator, { includeComments: true });
-
- if (tokenAfterDeclarator.value !== ",") {
- return null;
- }
-
- /*
- * `var x,y`
- * tokenAfterDeclarator ^^ afterComma
- */
- if (afterComma.range[0] === tokenAfterDeclarator.range[1]) {
- return fixer.replaceText(tokenAfterDeclarator, `; ${declaration.kind} `);
- }
-
- /*
- * `var x,
- * tokenAfterDeclarator ^
- * y`
- * ^ afterComma
- */
- if (
- afterComma.loc.start.line > tokenAfterDeclarator.loc.end.line ||
- afterComma.type === "Line" ||
- afterComma.type === "Block"
- ) {
- let lastComment = afterComma;
-
- while (lastComment.type === "Line" || lastComment.type === "Block") {
- lastComment = sourceCode.getTokenAfter(lastComment, { includeComments: true });
- }
-
- return fixer.replaceTextRange(
- [tokenAfterDeclarator.range[0], lastComment.range[0]],
- `;${sourceCode.text.slice(tokenAfterDeclarator.range[1], lastComment.range[0])}${declaration.kind} `
- );
- }
-
- return fixer.replaceText(tokenAfterDeclarator, `; ${declaration.kind}`);
- }).filter(x => x);
- }
-
- /**
- * Checks a given VariableDeclaration node for errors.
- * @param {ASTNode} node The VariableDeclaration node to check
- * @returns {void}
- * @private
- */
- function checkVariableDeclaration(node) {
- const parent = node.parent;
- const type = node.kind;
-
- if (!options[type]) {
- return;
- }
-
- const declarations = node.declarations;
- const declarationCounts = countDeclarations(declarations);
- const mixedRequires = declarations.some(isRequire) && !declarations.every(isRequire);
-
- if (options[type].initialized === MODE_ALWAYS) {
- if (options.separateRequires && mixedRequires) {
- context.report({
- node,
- message: "Split requires to be separated into a single block."
- });
- }
- }
-
- // consecutive
- const nodeIndex = (parent.body && parent.body.length > 0 && parent.body.indexOf(node)) || 0;
-
- if (nodeIndex > 0) {
- const previousNode = parent.body[nodeIndex - 1];
- const isPreviousNodeDeclaration = previousNode.type === "VariableDeclaration";
- const declarationsWithPrevious = declarations.concat(previousNode.declarations || []);
-
- if (
- isPreviousNodeDeclaration &&
- previousNode.kind === type &&
- !(declarationsWithPrevious.some(isRequire) && !declarationsWithPrevious.every(isRequire))
- ) {
- const previousDeclCounts = countDeclarations(previousNode.declarations);
-
- if (options[type].initialized === MODE_CONSECUTIVE && options[type].uninitialized === MODE_CONSECUTIVE) {
- context.report({
- node,
- message: "Combine this with the previous '{{type}}' statement.",
- data: {
- type
- },
- fix: joinDeclarations(declarations)
- });
- } else if (options[type].initialized === MODE_CONSECUTIVE && declarationCounts.initialized > 0 && previousDeclCounts.initialized > 0) {
- context.report({
- node,
- message: "Combine this with the previous '{{type}}' statement with initialized variables.",
- data: {
- type
- },
- fix: joinDeclarations(declarations)
- });
- } else if (options[type].uninitialized === MODE_CONSECUTIVE &&
- declarationCounts.uninitialized > 0 &&
- previousDeclCounts.uninitialized > 0) {
- context.report({
- node,
- message: "Combine this with the previous '{{type}}' statement with uninitialized variables.",
- data: {
- type
- },
- fix: joinDeclarations(declarations)
- });
- }
- }
- }
-
- // always
- if (!hasOnlyOneStatement(type, declarations)) {
- if (options[type].initialized === MODE_ALWAYS && options[type].uninitialized === MODE_ALWAYS) {
- context.report({
- node,
- message: "Combine this with the previous '{{type}}' statement.",
- data: {
- type
- },
- fix: joinDeclarations(declarations)
- });
- } else {
- if (options[type].initialized === MODE_ALWAYS && declarationCounts.initialized > 0) {
- context.report({
- node,
- message: "Combine this with the previous '{{type}}' statement with initialized variables.",
- data: {
- type
- },
- fix: joinDeclarations(declarations)
- });
- }
- if (options[type].uninitialized === MODE_ALWAYS && declarationCounts.uninitialized > 0) {
- if (node.parent.left === node && (node.parent.type === "ForInStatement" || node.parent.type === "ForOfStatement")) {
- return;
- }
- context.report({
- node,
- message: "Combine this with the previous '{{type}}' statement with uninitialized variables.",
- data: {
- type
- },
- fix: joinDeclarations(declarations)
- });
- }
- }
- }
-
- // never
- if (parent.type !== "ForStatement" || parent.init !== node) {
- const totalDeclarations = declarationCounts.uninitialized + declarationCounts.initialized;
-
- if (totalDeclarations > 1) {
- if (options[type].initialized === MODE_NEVER && options[type].uninitialized === MODE_NEVER) {
-
- // both initialized and uninitialized
- context.report({
- node,
- message: "Split '{{type}}' declarations into multiple statements.",
- data: {
- type
- },
- fix: splitDeclarations(node)
- });
- } else if (options[type].initialized === MODE_NEVER && declarationCounts.initialized > 0) {
-
- // initialized
- context.report({
- node,
- message: "Split initialized '{{type}}' declarations into multiple statements.",
- data: {
- type
- },
- fix: splitDeclarations(node)
- });
- } else if (options[type].uninitialized === MODE_NEVER && declarationCounts.uninitialized > 0) {
-
- // uninitialized
- context.report({
- node,
- message: "Split uninitialized '{{type}}' declarations into multiple statements.",
- data: {
- type
- },
- fix: splitDeclarations(node)
- });
- }
- }
- }
- }
-
- //--------------------------------------------------------------------------
- // Public API
- //--------------------------------------------------------------------------
-
- return {
- Program: startFunction,
- FunctionDeclaration: startFunction,
- FunctionExpression: startFunction,
- ArrowFunctionExpression: startFunction,
- BlockStatement: startBlock,
- ForStatement: startBlock,
- ForInStatement: startBlock,
- ForOfStatement: startBlock,
- SwitchStatement: startBlock,
- VariableDeclaration: checkVariableDeclaration,
- "ForStatement:exit": endBlock,
- "ForOfStatement:exit": endBlock,
- "ForInStatement:exit": endBlock,
- "SwitchStatement:exit": endBlock,
- "BlockStatement:exit": endBlock,
- "Program:exit": endFunction,
- "FunctionDeclaration:exit": endFunction,
- "FunctionExpression:exit": endFunction,
- "ArrowFunctionExpression:exit": endFunction
- };
-
- }
-};
projects / dotfiles / .git / blobdiff