185 lines
		
	
	
		
			5.8 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			185 lines
		
	
	
		
			5.8 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
/**
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 * @fileoverview A rule to set the maximum number of statements in a function.
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 * @author Ian Christian Myers
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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 { upperCaseFirst } = require("../shared/string-utils");
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//------------------------------------------------------------------------------
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// Rule Definition
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//------------------------------------------------------------------------------
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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 a maximum number of statements allowed in function blocks",
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            recommended: false,
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            url: "https://eslint.org/docs/latest/rules/max-statements"
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        },
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        schema: [
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            {
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                oneOf: [
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                    {
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                        type: "integer",
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                        minimum: 0
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                    },
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                    {
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                        type: "object",
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                        properties: {
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                            maximum: {
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                                type: "integer",
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                                minimum: 0
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                            },
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                            max: {
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                                type: "integer",
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                                minimum: 0
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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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            },
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            {
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                type: "object",
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                properties: {
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                    ignoreTopLevelFunctions: {
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                        type: "boolean"
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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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        messages: {
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            exceed: "{{name}} has too many statements ({{count}}). Maximum allowed is {{max}}."
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        }
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    },
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    create(context) {
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        //--------------------------------------------------------------------------
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        // Helpers
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        //--------------------------------------------------------------------------
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        const functionStack = [],
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            option = context.options[0],
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            ignoreTopLevelFunctions = context.options[1] && context.options[1].ignoreTopLevelFunctions || false,
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            topLevelFunctions = [];
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        let maxStatements = 10;
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        if (
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            typeof option === "object" &&
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            (Object.prototype.hasOwnProperty.call(option, "maximum") || Object.prototype.hasOwnProperty.call(option, "max"))
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        ) {
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            maxStatements = option.maximum || option.max;
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        } else if (typeof option === "number") {
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            maxStatements = option;
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        }
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        /**
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         * Reports a node if it has too many statements
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         * @param {ASTNode} node node to evaluate
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         * @param {int} count Number of statements in node
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         * @param {int} max Maximum number of statements allowed
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         * @returns {void}
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         * @private
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         */
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        function reportIfTooManyStatements(node, count, max) {
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            if (count > max) {
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                const name = upperCaseFirst(astUtils.getFunctionNameWithKind(node));
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                context.report({
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                    node,
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                    messageId: "exceed",
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                    data: { name, count, max }
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                });
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            }
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        }
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        /**
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         * When parsing a new function, store it in our function stack
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         * @returns {void}
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         * @private
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         */
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        function startFunction() {
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            functionStack.push(0);
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        }
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        /**
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         * Evaluate the node at the end of function
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         * @param {ASTNode} node node to evaluate
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         * @returns {void}
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         * @private
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         */
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        function endFunction(node) {
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            const count = functionStack.pop();
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            /*
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             * This rule does not apply to class static blocks, but we have to track them so
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             * that statements in them do not count as statements in the enclosing function.
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             */
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            if (node.type === "StaticBlock") {
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                return;
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            }
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            if (ignoreTopLevelFunctions && functionStack.length === 0) {
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                topLevelFunctions.push({ node, count });
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            } else {
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                reportIfTooManyStatements(node, count, maxStatements);
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            }
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        }
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        /**
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         * Increment the count of the functions
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         * @param {ASTNode} node node to evaluate
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         * @returns {void}
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         * @private
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         */
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        function countStatements(node) {
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            functionStack[functionStack.length - 1] += node.body.length;
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        }
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        //--------------------------------------------------------------------------
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        // Public API
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        //--------------------------------------------------------------------------
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        return {
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            FunctionDeclaration: startFunction,
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            FunctionExpression: startFunction,
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            ArrowFunctionExpression: startFunction,
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            StaticBlock: startFunction,
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            BlockStatement: countStatements,
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            "FunctionDeclaration:exit": endFunction,
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            "FunctionExpression:exit": endFunction,
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            "ArrowFunctionExpression:exit": endFunction,
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            "StaticBlock:exit": endFunction,
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            "Program:exit"() {
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                if (topLevelFunctions.length === 1) {
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                    return;
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                }
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                topLevelFunctions.forEach(element => {
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                    const count = element.count;
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                    const node = element.node;
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                    reportIfTooManyStatements(node, count, maxStatements);
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                });
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            }
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        };
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    }
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};
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