Add components

slider/node_modules/eslint/lib/rules/no-lonely-if.js

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+/**
+ * @fileoverview Rule to disallow if as the only statement in an else block
+ * @author Brandon Mills
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const astUtils = require("./utils/ast-utils");
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+/** @type {import('../types').Rule.RuleModule} */
+module.exports = {
+	meta: {
+		type: "suggestion",
+
+		docs: {
+			description:
+				"Disallow `if` statements as the only statement in `else` blocks",
+			recommended: false,
+			frozen: true,
+			url: "https://eslint.org/docs/latest/rules/no-lonely-if",
+		},
+
+		schema: [],
+		fixable: "code",
+
+		messages: {
+			unexpectedLonelyIf:
+				"Unexpected if as the only statement in an else block.",
+		},
+	},
+
+	create(context) {
+		const sourceCode = context.sourceCode;
+
+		return {
+			IfStatement(node) {
+				const parent = node.parent,
+					grandparent = parent.parent;
+
+				if (
+					parent &&
+					parent.type === "BlockStatement" &&
+					parent.body.length === 1 &&
+					!astUtils.areBracesNecessary(parent, sourceCode) &&
+					grandparent &&
+					grandparent.type === "IfStatement" &&
+					parent === grandparent.alternate
+				) {
+					context.report({
+						node,
+						messageId: "unexpectedLonelyIf",
+						fix(fixer) {
+							const openingElseCurly =
+								sourceCode.getFirstToken(parent);
+							const closingElseCurly =
+								sourceCode.getLastToken(parent);
+							const elseKeyword =
+								sourceCode.getTokenBefore(openingElseCurly);
+							const tokenAfterElseBlock =
+								sourceCode.getTokenAfter(closingElseCurly);
+							const lastIfToken = sourceCode.getLastToken(
+								node.consequent,
+							);
+							const sourceText = sourceCode.getText();
+
+							if (
+								sourceText
+									.slice(
+										openingElseCurly.range[1],
+										node.range[0],
+									)
+									.trim() ||
+								sourceText
+									.slice(
+										node.range[1],
+										closingElseCurly.range[0],
+									)
+									.trim()
+							) {
+								// Don't fix if there are any non-whitespace characters interfering (e.g. comments)
+								return null;
+							}
+
+							if (
+								node.consequent.type !== "BlockStatement" &&
+								lastIfToken.value !== ";" &&
+								tokenAfterElseBlock &&
+								(node.consequent.loc.end.line ===
+									tokenAfterElseBlock.loc.start.line ||
+									/^[([/+`-]/u.test(
+										tokenAfterElseBlock.value,
+									) ||
+									lastIfToken.value === "++" ||
+									lastIfToken.value === "--")
+							) {
+								/*
+								 * If the `if` statement has no block, and is not followed by a semicolon, make sure that fixing
+								 * the issue would not change semantics due to ASI. If this would happen, don't do a fix.
+								 */
+								return null;
+							}
+
+							return fixer.replaceTextRange(
+								[
+									openingElseCurly.range[0],
+									closingElseCurly.range[1],
+								],
+								(elseKeyword.range[1] ===
+								openingElseCurly.range[0]
+									? " "
+									: "") + sourceCode.getText(node),
+							);
+						},
+					});
+				}
+			},
+		};
+	},
+};