node_modules/eslint/lib/rules/generator-star-spacing.js

/**
 * @fileoverview Rule to check the spacing around the * in generator functions.
 * @author Jamund Ferguson
 * @deprecated in ESLint v8.53.0
 */

"use strict";

//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------

const OVERRIDE_SCHEMA = {
	oneOf: [
		{
			enum: ["before", "after", "both", "neither"],
		},
		{
			type: "object",
			properties: {
				before: { type: "boolean" },
				after: { type: "boolean" },
			},
			additionalProperties: false,
		},
	],
};

/** @type {import('../types').Rule.RuleModule} */
module.exports = {
	meta: {
		deprecated: {
			message: "Formatting rules are being moved out of ESLint core.",
			url: "https://eslint.org/blog/2023/10/deprecating-formatting-rules/",
			deprecatedSince: "8.53.0",
			availableUntil: "11.0.0",
			replacedBy: [
				{
					message:
						"ESLint Stylistic now maintains deprecated stylistic core rules.",
					url: "https://eslint.style/guide/migration",
					plugin: {
						name: "@stylistic/eslint-plugin",
						url: "https://eslint.style",
					},
					rule: {
						name: "generator-star-spacing",
						url: "https://eslint.style/rules/generator-star-spacing",
					},
				},
			],
		},
		type: "layout",

		docs: {
			description:
				"Enforce consistent spacing around `*` operators in generator functions",
			recommended: false,
			url: "https://eslint.org/docs/latest/rules/generator-star-spacing",
		},

		fixable: "whitespace",

		schema: [
			{
				oneOf: [
					{
						enum: ["before", "after", "both", "neither"],
					},
					{
						type: "object",
						properties: {
							before: { type: "boolean" },
							after: { type: "boolean" },
							named: OVERRIDE_SCHEMA,
							anonymous: OVERRIDE_SCHEMA,
							method: OVERRIDE_SCHEMA,
						},
						additionalProperties: false,
					},
				],
			},
		],

		messages: {
			missingBefore: "Missing space before *.",
			missingAfter: "Missing space after *.",
			unexpectedBefore: "Unexpected space before *.",
			unexpectedAfter: "Unexpected space after *.",
		},
	},

	create(context) {
		const optionDefinitions = {
			before: { before: true, after: false },
			after: { before: false, after: true },
			both: { before: true, after: true },
			neither: { before: false, after: false },
		};

		/**
		 * Returns resolved option definitions based on an option and defaults
		 * @param {any} option The option object or string value
		 * @param {Object} defaults The defaults to use if options are not present
		 * @returns {Object} the resolved object definition
		 */
		function optionToDefinition(option, defaults) {
			if (!option) {
				return defaults;
			}

			return typeof option === "string"
				? optionDefinitions[option]
				: Object.assign({}, defaults, option);
		}

		const modes = (function (option) {
			const defaults = optionToDefinition(
				option,
				optionDefinitions.before,
			);

			return {
				named: optionToDefinition(option.named, defaults),
				anonymous: optionToDefinition(option.anonymous, defaults),
				method: optionToDefinition(option.method, defaults),
			};
		})(context.options[0] || {});

		const sourceCode = context.sourceCode;

		/**
		 * Checks if the given token is a star token or not.
		 * @param {Token} token The token to check.
		 * @returns {boolean} `true` if the token is a star token.
		 */
		function isStarToken(token) {
			return token.value === "*" && token.type === "Punctuator";
		}

		/**
		 * Gets the generator star token of the given function node.
		 * @param {ASTNode} node The function node to get.
		 * @returns {Token} Found star token.
		 */
		function getStarToken(node) {
			return sourceCode.getFirstToken(
				node.parent.method || node.parent.type === "MethodDefinition"
					? node.parent
					: node,
				isStarToken,
			);
		}

		/**
		 * capitalize a given string.
		 * @param {string} str the given string.
		 * @returns {string} the capitalized string.
		 */
		function capitalize(str) {
			return str[0].toUpperCase() + str.slice(1);
		}

		/**
		 * Checks the spacing between two tokens before or after the star token.
		 * @param {string} kind Either "named", "anonymous", or "method"
		 * @param {string} side Either "before" or "after".
		 * @param {Token} leftToken `function` keyword token if side is "before", or
		 *     star token if side is "after".
		 * @param {Token} rightToken Star token if side is "before", or identifier
		 *     token if side is "after".
		 * @returns {void}
		 */
		function checkSpacing(kind, side, leftToken, rightToken) {
			if (
				!!(rightToken.range[0] - leftToken.range[1]) !==
				modes[kind][side]
			) {
				const after = leftToken.value === "*";
				const spaceRequired = modes[kind][side];
				const node = after ? leftToken : rightToken;
				const messageId = `${spaceRequired ? "missing" : "unexpected"}${capitalize(side)}`;

				context.report({
					node,
					messageId,
					fix(fixer) {
						if (spaceRequired) {
							if (after) {
								return fixer.insertTextAfter(node, " ");
							}
							return fixer.insertTextBefore(node, " ");
						}
						return fixer.removeRange([
							leftToken.range[1],
							rightToken.range[0],
						]);
					},
				});
			}
		}

		/**
		 * Enforces the spacing around the star if node is a generator function.
		 * @param {ASTNode} node A function expression or declaration node.
		 * @returns {void}
		 */
		function checkFunction(node) {
			if (!node.generator) {
				return;
			}

			const starToken = getStarToken(node);
			const prevToken = sourceCode.getTokenBefore(starToken);
			const nextToken = sourceCode.getTokenAfter(starToken);

			let kind = "named";

			if (
				node.parent.type === "MethodDefinition" ||
				(node.parent.type === "Property" && node.parent.method)
			) {
				kind = "method";
			} else if (!node.id) {
				kind = "anonymous";
			}

			// Only check before when preceded by `function`|`static` keyword
			if (
				!(
					kind === "method" &&
					starToken === sourceCode.getFirstToken(node.parent)
				)
			) {
				checkSpacing(kind, "before", prevToken, starToken);
			}

			checkSpacing(kind, "after", starToken, nextToken);
		}

		return {
			FunctionDeclaration: checkFunction,
			FunctionExpression: checkFunction,
		};
	},
};