| "use strict"; |
| var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) { |
| if (k2 === undefined) k2 = k; |
| Object.defineProperty(o, k2, { enumerable: true, get: function() { return m[k]; } }); |
| }) : (function(o, m, k, k2) { |
| if (k2 === undefined) k2 = k; |
| o[k2] = m[k]; |
| })); |
| var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) { |
| Object.defineProperty(o, "default", { enumerable: true, value: v }); |
| }) : function(o, v) { |
| o["default"] = v; |
| }); |
| var __importStar = (this && this.__importStar) || function (mod) { |
| if (mod && mod.__esModule) return mod; |
| var result = {}; |
| if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k); |
| __setModuleDefault(result, mod); |
| return result; |
| }; |
| Object.defineProperty(exports, "__esModule", { value: true }); |
| const utils_1 = require("@typescript-eslint/utils"); |
| const util = __importStar(require("../util")); |
| exports.default = util.createRule({ |
| name: 'prefer-nullish-coalescing', |
| meta: { |
| type: 'suggestion', |
| docs: { |
| description: 'Enforce the usage of the nullish coalescing operator instead of logical chaining', |
| recommended: false, |
| suggestion: true, |
| requiresTypeChecking: true, |
| }, |
| hasSuggestions: true, |
| messages: { |
| preferNullish: 'Prefer using nullish coalescing operator (`??`) instead of a logical or (`||`), as it is a safer operator.', |
| suggestNullish: 'Fix to nullish coalescing operator (`??`).', |
| }, |
| schema: [ |
| { |
| type: 'object', |
| properties: { |
| ignoreConditionalTests: { |
| type: 'boolean', |
| }, |
| ignoreMixedLogicalExpressions: { |
| type: 'boolean', |
| }, |
| forceSuggestionFixer: { |
| type: 'boolean', |
| }, |
| }, |
| additionalProperties: false, |
| }, |
| ], |
| }, |
| defaultOptions: [ |
| { |
| ignoreConditionalTests: true, |
| ignoreMixedLogicalExpressions: true, |
| }, |
| ], |
| create(context, [{ ignoreConditionalTests, ignoreMixedLogicalExpressions }]) { |
| const parserServices = util.getParserServices(context); |
| const sourceCode = context.getSourceCode(); |
| const checker = parserServices.program.getTypeChecker(); |
| return { |
| 'LogicalExpression[operator = "||"]'(node) { |
| const tsNode = parserServices.esTreeNodeToTSNodeMap.get(node); |
| const type = checker.getTypeAtLocation(tsNode.left); |
| const isNullish = util.isNullableType(type, { allowUndefined: true }); |
| if (!isNullish) { |
| return; |
| } |
| if (ignoreConditionalTests === true && isConditionalTest(node)) { |
| return; |
| } |
| const isMixedLogical = isMixedLogicalExpression(node); |
| if (ignoreMixedLogicalExpressions === true && isMixedLogical) { |
| return; |
| } |
| const barBarOperator = util.nullThrows(sourceCode.getTokenAfter(node.left, token => token.type === utils_1.AST_TOKEN_TYPES.Punctuator && |
| token.value === node.operator), util.NullThrowsReasons.MissingToken('operator', node.type)); |
| function* fix(fixer) { |
| if (node.parent && util.isLogicalOrOperator(node.parent)) { |
| // '&&' and '??' operations cannot be mixed without parentheses (e.g. a && b ?? c) |
| if (node.left.type === utils_1.AST_NODE_TYPES.LogicalExpression && |
| !util.isLogicalOrOperator(node.left.left)) { |
| yield fixer.insertTextBefore(node.left.right, '('); |
| } |
| else { |
| yield fixer.insertTextBefore(node.left, '('); |
| } |
| yield fixer.insertTextAfter(node.right, ')'); |
| } |
| yield fixer.replaceText(barBarOperator, '??'); |
| } |
| context.report({ |
| node: barBarOperator, |
| messageId: 'preferNullish', |
| suggest: [ |
| { |
| messageId: 'suggestNullish', |
| fix, |
| }, |
| ], |
| }); |
| }, |
| }; |
| }, |
| }); |
| function isConditionalTest(node) { |
| const parents = new Set([node]); |
| let current = node.parent; |
| while (current) { |
| parents.add(current); |
| if ((current.type === utils_1.AST_NODE_TYPES.ConditionalExpression || |
| current.type === utils_1.AST_NODE_TYPES.DoWhileStatement || |
| current.type === utils_1.AST_NODE_TYPES.IfStatement || |
| current.type === utils_1.AST_NODE_TYPES.ForStatement || |
| current.type === utils_1.AST_NODE_TYPES.WhileStatement) && |
| parents.has(current.test)) { |
| return true; |
| } |
| if ([ |
| utils_1.AST_NODE_TYPES.ArrowFunctionExpression, |
| utils_1.AST_NODE_TYPES.FunctionExpression, |
| ].includes(current.type)) { |
| /** |
| * This is a weird situation like: |
| * `if (() => a || b) {}` |
| * `if (function () { return a || b }) {}` |
| */ |
| return false; |
| } |
| current = current.parent; |
| } |
| return false; |
| } |
| function isMixedLogicalExpression(node) { |
| const seen = new Set(); |
| const queue = [node.parent, node.left, node.right]; |
| for (const current of queue) { |
| if (seen.has(current)) { |
| continue; |
| } |
| seen.add(current); |
| if (current && current.type === utils_1.AST_NODE_TYPES.LogicalExpression) { |
| if (current.operator === '&&') { |
| return true; |
| } |
| else if (current.operator === '||') { |
| // check the pieces of the node to catch cases like `a || b || c && d` |
| queue.push(current.parent, current.left, current.right); |
| } |
| } |
| } |
| return false; |
| } |
| //# sourceMappingURL=prefer-nullish-coalescing.js.map |