87 lines
3.4 KiB
Plaintext
87 lines
3.4 KiB
Plaintext
"use strict";
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var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
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if (k2 === undefined) k2 = k;
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var desc = Object.getOwnPropertyDescriptor(m, k);
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if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
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desc = { enumerable: true, get: function() { return m[k]; } };
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}
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Object.defineProperty(o, k2, desc);
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}) : (function(o, m, k, k2) {
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if (k2 === undefined) k2 = k;
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o[k2] = m[k];
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}));
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var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
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Object.defineProperty(o, "default", { enumerable: true, value: v });
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}) : function(o, v) {
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o["default"] = v;
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});
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var __importStar = (this && this.__importStar) || (function () {
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var ownKeys = function(o) {
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ownKeys = Object.getOwnPropertyNames || function (o) {
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var ar = [];
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for (var k in o) if (Object.prototype.hasOwnProperty.call(o, k)) ar[ar.length] = k;
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return ar;
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};
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return ownKeys(o);
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};
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return function (mod) {
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if (mod && mod.__esModule) return mod;
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var result = {};
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if (mod != null) for (var k = ownKeys(mod), i = 0; i < k.length; i++) if (k[i] !== "default") __createBinding(result, mod, k[i]);
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__setModuleDefault(result, mod);
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return result;
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};
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})();
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Object.defineProperty(exports, "__esModule", { value: true });
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const tsutils = __importStar(require("ts-api-utils"));
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const ts = __importStar(require("typescript"));
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const util_1 = require("../util");
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const getForStatementHeadLoc_1 = require("../util/getForStatementHeadLoc");
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exports.default = (0, util_1.createRule)({
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name: 'no-for-in-array',
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meta: {
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type: 'problem',
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docs: {
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description: 'Disallow iterating over an array with a for-in loop',
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recommended: 'recommended',
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requiresTypeChecking: true,
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},
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messages: {
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forInViolation: 'For-in loops over arrays skips holes, returns indices as strings, and may visit the prototype chain or other enumerable properties. Use a more robust iteration method such as for-of or array.forEach instead.',
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},
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schema: [],
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},
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defaultOptions: [],
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create(context) {
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return {
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ForInStatement(node) {
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const services = (0, util_1.getParserServices)(context);
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const checker = services.program.getTypeChecker();
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const type = (0, util_1.getConstrainedTypeAtLocation)(services, node.right);
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if (isArrayLike(checker, type)) {
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context.report({
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loc: (0, getForStatementHeadLoc_1.getForStatementHeadLoc)(context.sourceCode, node),
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messageId: 'forInViolation',
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});
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}
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},
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};
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},
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});
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function isArrayLike(checker, type) {
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return isTypeRecurser(type, t => t.getNumberIndexType() != null && hasArrayishLength(checker, t));
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}
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function hasArrayishLength(checker, type) {
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const lengthProperty = type.getProperty('length');
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if (lengthProperty == null) {
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return false;
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}
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return tsutils.isTypeFlagSet(checker.getTypeOfSymbol(lengthProperty), ts.TypeFlags.NumberLike);
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}
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function isTypeRecurser(type, predicate) {
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if (type.isUnionOrIntersection()) {
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return type.types.some(t => isTypeRecurser(t, predicate));
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}
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return predicate(type);
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}
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