325 lines
15 KiB
Plaintext
325 lines
15 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 utils_1 = require("@typescript-eslint/utils");
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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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exports.default = (0, util_1.createRule)({
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name: 'no-useless-default-assignment',
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meta: {
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type: 'suggestion',
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docs: {
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description: 'Disallow default values that will never be used',
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recommended: 'strict',
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requiresTypeChecking: true,
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},
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fixable: 'code',
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messages: {
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noStrictNullCheck: 'This rule requires the `strictNullChecks` compiler option to be turned on to function correctly.',
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preferOptionalSyntax: 'Using `= undefined` to make a parameter optional adds unnecessary runtime logic. Use the `?` optional syntax instead.',
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uselessDefaultAssignment: 'Default value is useless because the {{ type }} is not optional.',
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uselessUndefined: 'Default value is useless because it is undefined. Optional {{ type }}s are already undefined by default.',
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},
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schema: [
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{
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type: 'object',
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additionalProperties: false,
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properties: {
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allowRuleToRunWithoutStrictNullChecksIKnowWhatIAmDoing: {
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type: 'boolean',
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description: 'Unless this is set to `true`, the rule will error on every file whose `tsconfig.json` does _not_ have the `strictNullChecks` compiler option (or `strict`) set to `true`.',
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},
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},
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},
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],
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},
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defaultOptions: [
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{
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allowRuleToRunWithoutStrictNullChecksIKnowWhatIAmDoing: false,
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},
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],
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create(context, [{ allowRuleToRunWithoutStrictNullChecksIKnowWhatIAmDoing }]) {
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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 compilerOptions = services.program.getCompilerOptions();
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const isStrictNullChecks = tsutils.isStrictCompilerOptionEnabled(compilerOptions, 'strictNullChecks');
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if (!isStrictNullChecks &&
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allowRuleToRunWithoutStrictNullChecksIKnowWhatIAmDoing !== true) {
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context.report({
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loc: {
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start: { column: 0, line: 0 },
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end: { column: 0, line: 0 },
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},
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messageId: 'noStrictNullCheck',
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});
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}
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function canBeUndefined(type) {
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if ((0, util_1.isTypeAnyType)(type) || (0, util_1.isTypeUnknownType)(type)) {
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return true;
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}
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return tsutils
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.unionConstituents(type)
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.some(part => (0, util_1.isTypeFlagSet)(part, ts.TypeFlags.Undefined));
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}
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function getArrayElementType(arrayType, elementIndex) {
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if (checker.isTupleType(arrayType)) {
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const tupleArgs = checker.getTypeArguments(arrayType);
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if (elementIndex < tupleArgs.length) {
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return tupleArgs[elementIndex];
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}
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}
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return arrayType.getNumberIndexType() ?? null;
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}
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function checkAssignmentPattern(node) {
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if (node.right.type === utils_1.AST_NODE_TYPES.Identifier &&
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node.right.name === 'undefined') {
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const tsNode = services.esTreeNodeToTSNodeMap.get(node);
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if (ts.isParameter(tsNode) &&
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tsNode.type &&
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canBeUndefined(checker.getTypeFromTypeNode(tsNode.type))) {
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reportPreferOptionalSyntax(node);
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return;
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}
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const type = node.parent.type === utils_1.AST_NODE_TYPES.Property ||
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node.parent.type === utils_1.AST_NODE_TYPES.ArrayPattern
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? 'property'
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: 'parameter';
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reportUselessUndefined(node, type);
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return;
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}
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const parent = node.parent;
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if (parent.type === utils_1.AST_NODE_TYPES.ArrowFunctionExpression ||
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parent.type === utils_1.AST_NODE_TYPES.FunctionExpression) {
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const paramIndex = parent.params.indexOf(node);
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if (paramIndex !== -1) {
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const tsFunc = services.esTreeNodeToTSNodeMap.get(parent);
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// tsFunc is already a FunctionLike subtype; defensive runtime check
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// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
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if (ts.isFunctionLike(tsFunc)) {
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const contextualType = checker.getContextualType(tsFunc);
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if (!contextualType) {
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return;
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}
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const signatures = contextualType.getCallSignatures();
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if (signatures.length === 0 ||
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signatures[0].getDeclaration() === tsFunc) {
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return;
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}
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const defaultCanBeUsed = signatures.some(signature => {
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const params = signature.getParameters();
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if (paramIndex >= params.length) {
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return true;
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}
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const paramSymbol = params[paramIndex];
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if (paramSymbol.valueDeclaration &&
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(0, util_1.isRestParameterDeclaration)(paramSymbol.valueDeclaration)) {
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return true;
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}
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if (tsutils.isSymbolFlagSet(paramSymbol, ts.SymbolFlags.Optional)) {
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return true;
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}
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const paramType = checker.getTypeOfSymbol(paramSymbol);
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return (tsutils.isTypeParameter(paramType) || canBeUndefined(paramType));
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});
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if (!defaultCanBeUsed) {
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reportUselessDefaultAssignment(node, 'parameter');
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}
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}
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}
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return;
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}
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if (parent.type === utils_1.AST_NODE_TYPES.Property) {
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const propertyType = getTypeOfProperty(parent);
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if (!propertyType) {
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return;
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}
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if (!canBeUndefined(propertyType)) {
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reportUselessDefaultAssignment(node, 'property');
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}
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}
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else if (parent.type === utils_1.AST_NODE_TYPES.ArrayPattern) {
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const sourceType = getSourceTypeForPattern(parent);
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if (!sourceType) {
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return;
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}
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if (!checker.isTupleType(sourceType)) {
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return;
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}
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const tupleArgs = checker.getTypeArguments(sourceType);
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const elementIndex = parent.elements.indexOf(node);
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if (elementIndex < 0 || elementIndex >= tupleArgs.length) {
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return;
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}
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const elementType = tupleArgs[elementIndex];
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if (!canBeUndefined(elementType)) {
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reportUselessDefaultAssignment(node, 'property');
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}
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}
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}
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function getTypeOfProperty(node) {
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const objectPattern = node.parent;
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const sourceType = getSourceTypeForPattern(objectPattern);
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if (!sourceType) {
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return null;
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}
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const propertyName = getPropertyName(node.key);
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if (!propertyName) {
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return null;
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}
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const symbol = sourceType.getProperty(propertyName);
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if (!symbol) {
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return null;
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}
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if (tsutils.isSymbolFlagSet(symbol, ts.SymbolFlags.Optional)) {
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const parent = objectPattern.parent;
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if (parent.type === utils_1.AST_NODE_TYPES.VariableDeclarator &&
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parent.init &&
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hasConditionalInitializer(objectPattern)) {
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const propertyName = getPropertyName(node.key);
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if (!propertyName ||
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!hasPropertyInAllBranches(parent.init, propertyName)) {
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return null;
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}
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}
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}
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return checker.getTypeOfSymbol(symbol);
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}
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function hasConditionalInitializer(node) {
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const parent = node.parent;
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if (!parent) {
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return false;
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}
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if (parent.type === utils_1.AST_NODE_TYPES.VariableDeclarator && parent.init) {
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return (parent.init.type === utils_1.AST_NODE_TYPES.ConditionalExpression ||
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parent.init.type === utils_1.AST_NODE_TYPES.LogicalExpression);
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}
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return hasConditionalInitializer(parent);
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}
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function getSourceTypeForPattern(pattern) {
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const parent = (0, util_1.nullThrows)(pattern.parent, util_1.NullThrowsReasons.MissingParent);
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if (parent.type === utils_1.AST_NODE_TYPES.VariableDeclarator && parent.init) {
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const tsNode = services.esTreeNodeToTSNodeMap.get(parent.init);
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return checker.getTypeAtLocation(tsNode);
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}
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if ((0, util_1.isFunction)(parent)) {
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let paramIndex = parent.params.indexOf(pattern);
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const tsFunc = services.esTreeNodeToTSNodeMap.get(parent);
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const signature = (0, util_1.nullThrows)(checker.getSignatureFromDeclaration(tsFunc), util_1.NullThrowsReasons.MissingToken('signature', 'function'));
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const params = signature.getParameters();
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if (signature.thisParameter) {
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paramIndex--;
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}
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if (paramIndex < 0 || paramIndex >= params.length) {
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return null;
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}
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return checker.getTypeOfSymbol(params[paramIndex]);
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}
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if (parent.type === utils_1.AST_NODE_TYPES.AssignmentPattern) {
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return getSourceTypeForPattern(parent);
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}
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if (parent.type === utils_1.AST_NODE_TYPES.Property) {
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return getTypeOfProperty(parent);
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}
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if (parent.type === utils_1.AST_NODE_TYPES.ArrayPattern) {
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const arrayType = getSourceTypeForPattern(parent);
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if (!arrayType) {
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return null;
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}
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const elementIndex = parent.elements.indexOf(pattern);
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return getArrayElementType(arrayType, elementIndex);
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}
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return null;
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}
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function getPropertyName(key) {
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switch (key.type) {
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case utils_1.AST_NODE_TYPES.Identifier:
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return key.name;
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case utils_1.AST_NODE_TYPES.Literal:
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return String(key.value);
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case utils_1.AST_NODE_TYPES.TemplateLiteral:
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return key.expressions.length ? null : key.quasis[0].value.cooked;
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default:
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return null;
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}
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}
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function reportUselessDefaultAssignment(node, type) {
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context.report({
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node: node.right,
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messageId: 'uselessDefaultAssignment',
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data: { type },
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fix: fixer => removeDefault(fixer, node),
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});
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}
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function reportUselessUndefined(node, type) {
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context.report({
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node: node.right,
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messageId: 'uselessUndefined',
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data: { type },
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fix: fixer => removeDefault(fixer, node),
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});
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}
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function reportPreferOptionalSyntax(node) {
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context.report({
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node: node.right,
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messageId: 'preferOptionalSyntax',
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*fix(fixer) {
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yield removeDefault(fixer, node);
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const { left } = node;
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if (left.type === utils_1.AST_NODE_TYPES.Identifier) {
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yield fixer.insertTextAfterRange([left.range[0], left.range[0] + left.name.length], '?');
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}
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},
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});
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}
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function removeDefault(fixer, node) {
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const start = node.left.range[1];
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const end = node.range[1];
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return fixer.removeRange([start, end]);
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}
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function hasPropertyInAllBranches(expression, propertyName) {
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return ((expression.type === utils_1.AST_NODE_TYPES.ObjectExpression &&
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expression.properties.some(prop => prop.type === utils_1.AST_NODE_TYPES.Property &&
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getPropertyName(prop.key) === propertyName)) ||
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(expression.type === utils_1.AST_NODE_TYPES.ConditionalExpression &&
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hasPropertyInAllBranches(expression.consequent, propertyName) &&
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hasPropertyInAllBranches(expression.alternate, propertyName)));
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}
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return {
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AssignmentPattern: checkAssignmentPattern,
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};
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},
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});
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