eslint/lib/rules/require-jsdoc.js

/**
 * @fileoverview Rule to check for jsdoc presence.
 * @author Gyandeep Singh
 */
"use strict";

module.exports = {
    meta: {
        docs: {
            description: "require JSDoc comments",
            category: "Stylistic Issues",
            recommended: false,
            url: "https://eslint.org/docs/rules/require-jsdoc"
        },

        schema: [
            {
                type: "object",
                properties: {
                    require: {
                        type: "object",
                        properties: {
                            ClassDeclaration: {
                                type: "boolean"
                            },
                            MethodDefinition: {
                                type: "boolean"
                            },
                            FunctionDeclaration: {
                                type: "boolean"
                            },
                            ArrowFunctionExpression: {
                                type: "boolean"
                            },
                            FunctionExpression: {
                                type: "boolean"
                            }
                        },
                        additionalProperties: false
                    }
                },
                additionalProperties: false
            }
        ]
    },

    create(context) {
        const source = context.getSourceCode();
        const DEFAULT_OPTIONS = {
            FunctionDeclaration: true,
            MethodDefinition: false,
            ClassDeclaration: false,
            ArrowFunctionExpression: false,
            FunctionExpression: false
        };
        const options = Object.assign(DEFAULT_OPTIONS, context.options[0] && context.options[0].require || {});

        /**
         * Report the error message
         * @param {ASTNode} node node to report
         * @returns {void}
         */
        function report(node) {
            context.report({ node, message: "Missing JSDoc comment." });
        }

        /**
         * Check if the jsdoc comment is present or not.
         * @param {ASTNode} node node to examine
         * @returns {void}
         */
        function checkJsDoc(node) {
            const jsdocComment = source.getJSDocComment(node);

            if (!jsdocComment) {
                report(node);
            }
        }

        return {
            FunctionDeclaration(node) {
                if (options.FunctionDeclaration) {
                    checkJsDoc(node);
                }
            },
            FunctionExpression(node) {
                if (
                    (options.MethodDefinition && node.parent.type === "MethodDefinition") ||
                    (options.FunctionExpression && (node.parent.type === "VariableDeclarator" || (node.parent.type === "Property" && node === node.parent.value)))
                ) {
                    checkJsDoc(node);
                }
            },
            ClassDeclaration(node) {
                if (options.ClassDeclaration) {
                    checkJsDoc(node);
                }
            },
            ArrowFunctionExpression(node) {
                if (options.ArrowFunctionExpression && node.parent.type === "VariableDeclarator") {
                    checkJsDoc(node);
                }
            }
        };
    }
};