Add components

slider/node_modules/eslint/lib/rules/init-declarations.js

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+/**
+ * @fileoverview A rule to control the style of variable initializations.
+ * @author Colin Ihrig
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+const CONSTANT_BINDINGS = new Set(["const", "using", "await using"]);
+
+/**
+ * Checks whether or not a given node is a for loop.
+ * @param {ASTNode} block A node to check.
+ * @returns {boolean} `true` when the node is a for loop.
+ */
+function isForLoop(block) {
+	return (
+		block.type === "ForInStatement" ||
+		block.type === "ForOfStatement" ||
+		block.type === "ForStatement"
+	);
+}
+
+/**
+ * Checks whether or not a given declarator node has its initializer.
+ * @param {ASTNode} node A declarator node to check.
+ * @returns {boolean} `true` when the node has its initializer.
+ */
+function isInitialized(node) {
+	const declaration = node.parent;
+	const block = declaration.parent;
+
+	if (isForLoop(block)) {
+		if (block.type === "ForStatement") {
+			return block.init === declaration;
+		}
+		return block.left === declaration;
+	}
+	return Boolean(node.init);
+}
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+/** @type {import('../types').Rule.RuleModule} */
+module.exports = {
+	meta: {
+		type: "suggestion",
+		dialects: ["typescript", "javascript"],
+		language: "javascript",
+
+		docs: {
+			description:
+				"Require or disallow initialization in variable declarations",
+			recommended: false,
+			frozen: true,
+			url: "https://eslint.org/docs/latest/rules/init-declarations",
+		},
+
+		schema: {
+			anyOf: [
+				{
+					type: "array",
+					items: [
+						{
+							enum: ["always"],
+						},
+					],
+					minItems: 0,
+					maxItems: 1,
+				},
+				{
+					type: "array",
+					items: [
+						{
+							enum: ["never"],
+						},
+						{
+							type: "object",
+							properties: {
+								ignoreForLoopInit: {
+									type: "boolean",
+								},
+							},
+							additionalProperties: false,
+						},
+					],
+					minItems: 0,
+					maxItems: 2,
+				},
+			],
+		},
+		messages: {
+			initialized:
+				"Variable '{{idName}}' should be initialized on declaration.",
+			notInitialized:
+				"Variable '{{idName}}' should not be initialized on declaration.",
+		},
+	},
+
+	create(context) {
+		const MODE_ALWAYS = "always",
+			MODE_NEVER = "never";
+
+		const mode = context.options[0] || MODE_ALWAYS;
+		const params = context.options[1] || {};
+
+		// Track whether we're inside a declared namespace
+		let insideDeclaredNamespace = false;
+
+		//--------------------------------------------------------------------------
+		// Public API
+		//--------------------------------------------------------------------------
+
+		return {
+			TSModuleDeclaration(node) {
+				if (node.declare) {
+					insideDeclaredNamespace = true;
+				}
+			},
+
+			"TSModuleDeclaration:exit"(node) {
+				if (node.declare) {
+					insideDeclaredNamespace = false;
+				}
+			},
+
+			"VariableDeclaration:exit"(node) {
+				const kind = node.kind,
+					declarations = node.declarations;
+
+				if (node.declare || insideDeclaredNamespace) {
+					return;
+				}
+
+				for (let i = 0; i < declarations.length; ++i) {
+					const declaration = declarations[i],
+						id = declaration.id,
+						initialized = isInitialized(declaration),
+						isIgnoredForLoop =
+							params.ignoreForLoopInit && isForLoop(node.parent);
+					let messageId = "";
+
+					if (mode === MODE_ALWAYS && !initialized) {
+						messageId = "initialized";
+					} else if (
+						mode === MODE_NEVER &&
+						!CONSTANT_BINDINGS.has(kind) &&
+						initialized &&
+						!isIgnoredForLoop
+					) {
+						messageId = "notInitialized";
+					}
+
+					if (id.type === "Identifier" && messageId) {
+						context.report({
+							node: declaration,
+							messageId,
+							data: {
+								idName: id.name,
+							},
+						});
+					}
+				}
+			},
+		};
+	},
+};