.config/coc/extensions/node_modules/coc-prettier/node_modules/eslint/lib/rules/max-statements-per-line.js

   1 /**
   2  * @fileoverview Specify the maximum number of statements allowed per line.
   3  * @author Kenneth Williams
   4  */
   5 "use strict";
   6
   7 //------------------------------------------------------------------------------
   8 // Requirements
   9 //------------------------------------------------------------------------------
  10
  11 const astUtils = require("./utils/ast-utils");
  12
  13 //------------------------------------------------------------------------------
  14 // Rule Definition
  15 //------------------------------------------------------------------------------
  16
  17 module.exports = {
  18     meta: {
  19         type: "layout",
  20
  21         docs: {
  22             description: "enforce a maximum number of statements allowed per line",
  23             category: "Stylistic Issues",
  24             recommended: false,
  25             url: "https://eslint.org/docs/rules/max-statements-per-line"
  26         },
  27
  28         schema: [
  29             {
  30                 type: "object",
  31                 properties: {
  32                     max: {
  33                         type: "integer",
  34                         minimum: 1,
  35                         default: 1
  36                     }
  37                 },
  38                 additionalProperties: false
  39             }
  40         ],
  41         messages: {
  42             exceed: "This line has {{numberOfStatementsOnThisLine}} {{statements}}. Maximum allowed is {{maxStatementsPerLine}}."
  43         }
  44     },
  45
  46     create(context) {
  47
  48         const sourceCode = context.getSourceCode(),
  49             options = context.options[0] || {},
  50             maxStatementsPerLine = typeof options.max !== "undefined" ? options.max : 1;
  51
  52         let lastStatementLine = 0,
  53             numberOfStatementsOnThisLine = 0,
  54             firstExtraStatement;
  55
  56         //--------------------------------------------------------------------------
  57         // Helpers
  58         //--------------------------------------------------------------------------
  59
  60         const SINGLE_CHILD_ALLOWED = /^(?:(?:DoWhile|For|ForIn|ForOf|If|Labeled|While)Statement|Export(?:Default|Named)Declaration)$/u;
  61
  62         /**
  63          * Reports with the first extra statement, and clears it.
  64          * @returns {void}
  65          */
  66         function reportFirstExtraStatementAndClear() {
  67             if (firstExtraStatement) {
  68                 context.report({
  69                     node: firstExtraStatement,
  70                     messageId: "exceed",
  71                     data: {
  72                         numberOfStatementsOnThisLine,
  73                         maxStatementsPerLine,
  74                         statements: numberOfStatementsOnThisLine === 1 ? "statement" : "statements"
  75                     }
  76                 });
  77             }
  78             firstExtraStatement = null;
  79         }
  80
  81         /**
  82          * Gets the actual last token of a given node.
  83          * @param {ASTNode} node A node to get. This is a node except EmptyStatement.
  84          * @returns {Token} The actual last token.
  85          */
  86         function getActualLastToken(node) {
  87             return sourceCode.getLastToken(node, astUtils.isNotSemicolonToken);
  88         }
  89
  90         /**
  91          * Addresses a given node.
  92          * It updates the state of this rule, then reports the node if the node violated this rule.
  93          * @param {ASTNode} node A node to check.
  94          * @returns {void}
  95          */
  96         function enterStatement(node) {
  97             const line = node.loc.start.line;
  98
  99             /*
 100              * Skip to allow non-block statements if this is direct child of control statements.
 101              * `if (a) foo();` is counted as 1.
 102              * But `if (a) foo(); else foo();` should be counted as 2.
 103              */
 104             if (SINGLE_CHILD_ALLOWED.test(node.parent.type) &&
 105                 node.parent.alternate !== node
 106             ) {
 107                 return;
 108             }
 109
 110             // Update state.
 111             if (line === lastStatementLine) {
 112                 numberOfStatementsOnThisLine += 1;
 113             } else {
 114                 reportFirstExtraStatementAndClear();
 115                 numberOfStatementsOnThisLine = 1;
 116                 lastStatementLine = line;
 117             }
 118
 119             // Reports if the node violated this rule.
 120             if (numberOfStatementsOnThisLine === maxStatementsPerLine + 1) {
 121                 firstExtraStatement = firstExtraStatement || node;
 122             }
 123         }
 124
 125         /**
 126          * Updates the state of this rule with the end line of leaving node to check with the next statement.
 127          * @param {ASTNode} node A node to check.
 128          * @returns {void}
 129          */
 130         function leaveStatement(node) {
 131             const line = getActualLastToken(node).loc.end.line;
 132
 133             // Update state.
 134             if (line !== lastStatementLine) {
 135                 reportFirstExtraStatementAndClear();
 136                 numberOfStatementsOnThisLine = 1;
 137                 lastStatementLine = line;
 138             }
 139         }
 140
 141         //--------------------------------------------------------------------------
 142         // Public API
 143         //--------------------------------------------------------------------------
 144
 145         return {
 146             BreakStatement: enterStatement,
 147             ClassDeclaration: enterStatement,
 148             ContinueStatement: enterStatement,
 149             DebuggerStatement: enterStatement,
 150             DoWhileStatement: enterStatement,
 151             ExpressionStatement: enterStatement,
 152             ForInStatement: enterStatement,
 153             ForOfStatement: enterStatement,
 154             ForStatement: enterStatement,
 155             FunctionDeclaration: enterStatement,
 156             IfStatement: enterStatement,
 157             ImportDeclaration: enterStatement,
 158             LabeledStatement: enterStatement,
 159             ReturnStatement: enterStatement,
 160             SwitchStatement: enterStatement,
 161             ThrowStatement: enterStatement,
 162             TryStatement: enterStatement,
 163             VariableDeclaration: enterStatement,
 164             WhileStatement: enterStatement,
 165             WithStatement: enterStatement,
 166             ExportNamedDeclaration: enterStatement,
 167             ExportDefaultDeclaration: enterStatement,
 168             ExportAllDeclaration: enterStatement,
 169
 170             "BreakStatement:exit": leaveStatement,
 171             "ClassDeclaration:exit": leaveStatement,
 172             "ContinueStatement:exit": leaveStatement,
 173             "DebuggerStatement:exit": leaveStatement,
 174             "DoWhileStatement:exit": leaveStatement,
 175             "ExpressionStatement:exit": leaveStatement,
 176             "ForInStatement:exit": leaveStatement,
 177             "ForOfStatement:exit": leaveStatement,
 178             "ForStatement:exit": leaveStatement,
 179             "FunctionDeclaration:exit": leaveStatement,
 180             "IfStatement:exit": leaveStatement,
 181             "ImportDeclaration:exit": leaveStatement,
 182             "LabeledStatement:exit": leaveStatement,
 183             "ReturnStatement:exit": leaveStatement,
 184             "SwitchStatement:exit": leaveStatement,
 185             "ThrowStatement:exit": leaveStatement,
 186             "TryStatement:exit": leaveStatement,
 187             "VariableDeclaration:exit": leaveStatement,
 188             "WhileStatement:exit": leaveStatement,
 189             "WithStatement:exit": leaveStatement,
 190             "ExportNamedDeclaration:exit": leaveStatement,
 191             "ExportDefaultDeclaration:exit": leaveStatement,
 192             "ExportAllDeclaration:exit": leaveStatement,
 193             "Program:exit": reportFirstExtraStatementAndClear
 194         };
 195     }
 196 };