Add components

slider/node_modules/eslint/lib/rules/no-unneeded-ternary.js

@@ -0,0 +1,232 @@
+/**
+ * @fileoverview Rule to flag no-unneeded-ternary
+ * @author Gyandeep Singh
+ */
+
+"use strict";
+
+const astUtils = require("./utils/ast-utils");
+
+// Operators that always result in a boolean value
+const BOOLEAN_OPERATORS = new Set([
+	"==",
+	"===",
+	"!=",
+	"!==",
+	">",
+	">=",
+	"<",
+	"<=",
+	"in",
+	"instanceof",
+]);
+const OPERATOR_INVERSES = {
+	"==": "!=",
+	"!=": "==",
+	"===": "!==",
+	"!==": "===",
+
+	// Operators like < and >= are not true inverses, since both will return false with NaN.
+};
+const OR_PRECEDENCE = astUtils.getPrecedence({
+	type: "LogicalExpression",
+	operator: "||",
+});
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+/** @type {import('../types').Rule.RuleModule} */
+module.exports = {
+	meta: {
+		type: "suggestion",
+
+		defaultOptions: [{ defaultAssignment: true }],
+
+		docs: {
+			description:
+				"Disallow ternary operators when simpler alternatives exist",
+			recommended: false,
+			frozen: true,
+			url: "https://eslint.org/docs/latest/rules/no-unneeded-ternary",
+		},
+
+		schema: [
+			{
+				type: "object",
+				properties: {
+					defaultAssignment: {
+						type: "boolean",
+					},
+				},
+				additionalProperties: false,
+			},
+		],
+
+		fixable: "code",
+
+		messages: {
+			unnecessaryConditionalExpression:
+				"Unnecessary use of boolean literals in conditional expression.",
+			unnecessaryConditionalAssignment:
+				"Unnecessary use of conditional expression for default assignment.",
+		},
+	},
+
+	create(context) {
+		const [{ defaultAssignment }] = context.options;
+		const sourceCode = context.sourceCode;
+
+		/**
+		 * Test if the node is a boolean literal
+		 * @param {ASTNode} node The node to report.
+		 * @returns {boolean} True if the its a boolean literal
+		 * @private
+		 */
+		function isBooleanLiteral(node) {
+			return node.type === "Literal" && typeof node.value === "boolean";
+		}
+
+		/**
+		 * Creates an expression that represents the boolean inverse of the expression represented by the original node
+		 * @param {ASTNode} node A node representing an expression
+		 * @returns {string} A string representing an inverted expression
+		 */
+		function invertExpression(node) {
+			if (
+				node.type === "BinaryExpression" &&
+				Object.hasOwn(OPERATOR_INVERSES, node.operator)
+			) {
+				const operatorToken = sourceCode.getFirstTokenBetween(
+					node.left,
+					node.right,
+					token => token.value === node.operator,
+				);
+				const text = sourceCode.getText();
+
+				return (
+					text.slice(node.range[0], operatorToken.range[0]) +
+					OPERATOR_INVERSES[node.operator] +
+					text.slice(operatorToken.range[1], node.range[1])
+				);
+			}
+
+			if (
+				astUtils.getPrecedence(node) <
+				astUtils.getPrecedence({ type: "UnaryExpression" })
+			) {
+				return `!(${astUtils.getParenthesisedText(sourceCode, node)})`;
+			}
+			return `!${astUtils.getParenthesisedText(sourceCode, node)}`;
+		}
+
+		/**
+		 * Tests if a given node always evaluates to a boolean value
+		 * @param {ASTNode} node An expression node
+		 * @returns {boolean} True if it is determined that the node will always evaluate to a boolean value
+		 */
+		function isBooleanExpression(node) {
+			return (
+				(node.type === "BinaryExpression" &&
+					BOOLEAN_OPERATORS.has(node.operator)) ||
+				(node.type === "UnaryExpression" && node.operator === "!")
+			);
+		}
+
+		/**
+		 * Test if the node matches the pattern id ? id : expression
+		 * @param {ASTNode} node The ConditionalExpression to check.
+		 * @returns {boolean} True if the pattern is matched, and false otherwise
+		 * @private
+		 */
+		function matchesDefaultAssignment(node) {
+			return (
+				node.test.type === "Identifier" &&
+				node.consequent.type === "Identifier" &&
+				node.test.name === node.consequent.name
+			);
+		}
+
+		return {
+			ConditionalExpression(node) {
+				if (
+					isBooleanLiteral(node.alternate) &&
+					isBooleanLiteral(node.consequent)
+				) {
+					context.report({
+						node,
+						messageId: "unnecessaryConditionalExpression",
+						fix(fixer) {
+							if (
+								node.consequent.value === node.alternate.value
+							) {
+								// Replace `foo ? true : true` with just `true`, but don't replace `foo() ? true : true`
+								return node.test.type === "Identifier"
+									? fixer.replaceText(
+											node,
+											node.consequent.value.toString(),
+										)
+									: null;
+							}
+							if (node.alternate.value) {
+								// Replace `foo() ? false : true` with `!(foo())`
+								return fixer.replaceText(
+									node,
+									invertExpression(node.test),
+								);
+							}
+
+							// Replace `foo ? true : false` with `foo` if `foo` is guaranteed to be a boolean, or `!!foo` otherwise.
+
+							return fixer.replaceText(
+								node,
+								isBooleanExpression(node.test)
+									? astUtils.getParenthesisedText(
+											sourceCode,
+											node.test,
+										)
+									: `!${invertExpression(node.test)}`,
+							);
+						},
+					});
+				} else if (
+					!defaultAssignment &&
+					matchesDefaultAssignment(node)
+				) {
+					context.report({
+						node,
+						messageId: "unnecessaryConditionalAssignment",
+						fix(fixer) {
+							const shouldParenthesizeAlternate =
+								(astUtils.getPrecedence(node.alternate) <
+									OR_PRECEDENCE ||
+									astUtils.isCoalesceExpression(
+										node.alternate,
+									)) &&
+								!astUtils.isParenthesised(
+									sourceCode,
+									node.alternate,
+								);
+							const alternateText = shouldParenthesizeAlternate
+								? `(${sourceCode.getText(node.alternate)})`
+								: astUtils.getParenthesisedText(
+										sourceCode,
+										node.alternate,
+									);
+							const testText = astUtils.getParenthesisedText(
+								sourceCode,
+								node.test,
+							);
+
+							return fixer.replaceText(
+								node,
+								`${testText} || ${alternateText}`,
+							);
+						},
+					});
+				}
+			},
+		};
+	},
+};