/**
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* @fileoverview Rule to check multiple var declarations per line
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* @author Alberto Rodríguez
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*/
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"use strict";
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//------------------------------------------------------------------------------
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// Rule Definition
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//------------------------------------------------------------------------------
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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: "require or disallow newlines around variable declarations",
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category: "Stylistic Issues",
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recommended: false,
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url: "https://eslint.org/docs/rules/one-var-declaration-per-line"
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},
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schema: [
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{
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enum: ["always", "initializations"]
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}
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],
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fixable: "whitespace",
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messages: {
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expectVarOnNewline: "Expected variable declaration to be on a new line."
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}
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},
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create(context) {
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const always = context.options[0] === "always";
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//--------------------------------------------------------------------------
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// Helpers
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//--------------------------------------------------------------------------
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/**
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* Determine if provided keyword is a variant of for specifiers
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* @private
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* @param {string} keyword keyword to test
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* @returns {boolean} True if `keyword` is a variant of for specifier
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*/
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function isForTypeSpecifier(keyword) {
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return keyword === "ForStatement" || keyword === "ForInStatement" || keyword === "ForOfStatement";
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}
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/**
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* Checks newlines around variable declarations.
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* @private
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* @param {ASTNode} node `VariableDeclaration` node to test
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* @returns {void}
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*/
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function checkForNewLine(node) {
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if (isForTypeSpecifier(node.parent.type)) {
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return;
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}
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const declarations = node.declarations;
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let prev;
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declarations.forEach(current => {
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if (prev && prev.loc.end.line === current.loc.start.line) {
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if (always || prev.init || current.init) {
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context.report({
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node,
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messageId: "expectVarOnNewline",
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loc: current.loc,
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fix: fixer => fixer.insertTextBefore(current, "\n")
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});
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}
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}
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prev = current;
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});
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}
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//--------------------------------------------------------------------------
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// Public
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//--------------------------------------------------------------------------
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return {
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VariableDeclaration: checkForNewLine
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};
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}
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};
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