130 lines
5.4 KiB
JavaScript
130 lines
5.4 KiB
JavaScript
"use strict";
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/**
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* @license
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* Copyright 2017 Palantir Technologies, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.Rule = void 0;
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var tslib_1 = require("tslib");
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var tsutils = require("tsutils");
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var ts = require("typescript");
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var Lint = require("../index");
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var Rule = /** @class */ (function (_super) {
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tslib_1.__extends(Rule, _super);
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function Rule() {
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return _super !== null && _super.apply(this, arguments) || this;
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}
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Rule.prototype.apply = function (sourceFile) {
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return this.applyWithFunction(sourceFile, walk);
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};
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Rule.prototype.applyWithProgram = function (sourceFile, program) {
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return this.applyWithFunction(sourceFile, walk, undefined, program.getTypeChecker());
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};
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Rule.metadata = {
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description: "Prevents unnecessary and/or misleading scope bindings on functions.",
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optionExamples: [true],
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options: null,
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optionsDescription: "Not configurable.",
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rationale: Lint.Utils.dedent(templateObject_1 || (templateObject_1 = tslib_1.__makeTemplateObject(["\n `function` expressions that are immediately bound to `this` are equivalent to `() =>` arrow lambdas.\n Additionally, there's no use in binding a scope to an arrow lambda, as it already has one.\n "], ["\n \\`function\\` expressions that are immediately bound to \\`this\\` are equivalent to \\`() =>\\` arrow lambdas.\n Additionally, there's no use in binding a scope to an arrow lambda, as it already has one.\n "]))),
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requiresTypeInfo: true,
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ruleName: "unnecessary-bind",
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type: "style",
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typescriptOnly: false,
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};
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Rule.FAILURE_STRING_FUNCTION = "Don't bind `this` without arguments as a scope to a function. Use an arrow lambda instead.";
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Rule.FAILURE_STRING_ARROW = "Don't bind scopes to arrow lambdas, as they already have a bound scope.";
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return Rule;
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}(Lint.Rules.OptionallyTypedRule));
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exports.Rule = Rule;
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function walk(context, typeChecker) {
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var variableUsage = tsutils.collectVariableUsage(context.sourceFile);
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function checkArrowFunction(node) {
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if (node.arguments.length !== 1) {
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return;
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}
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context.addFailureAtNode(node, Rule.FAILURE_STRING_ARROW);
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}
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function canFunctionExpressionBeFixed(callExpression, valueDeclaration) {
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if (callExpression.arguments.length !== 1 ||
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callExpression.arguments[0].kind !== ts.SyntaxKind.ThisKeyword ||
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valueDeclaration.asteriskToken !== undefined ||
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valueDeclaration.decorators !== undefined) {
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return false;
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}
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var name = valueDeclaration.name;
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if (name === undefined) {
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return true;
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}
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var nameInfo = variableUsage.get(name);
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return nameInfo === undefined || nameInfo.uses.length === 0;
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}
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function checkFunctionExpression(callExpression, valueDeclaration) {
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if (!canFunctionExpressionBeFixed(callExpression, valueDeclaration)) {
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return;
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}
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context.addFailureAtNode(callExpression, Rule.FAILURE_STRING_FUNCTION);
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}
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function getArrowFunctionDeclaration(node) {
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if (typeChecker === undefined) {
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return undefined;
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}
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var symbol = typeChecker.getTypeAtLocation(node).symbol;
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if (symbol === undefined) {
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return undefined;
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}
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var valueDeclaration = symbol.valueDeclaration;
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if (valueDeclaration === undefined) {
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return undefined;
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}
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if (!tsutils.isArrowFunction(valueDeclaration)) {
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return undefined;
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}
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return valueDeclaration;
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}
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function isDecoratedPropertyMember(node) {
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return (node.parent !== undefined &&
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tsutils.isPropertyDeclaration(node.parent) &&
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node.parent.decorators !== undefined);
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}
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function checkCallExpression(node) {
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if (isDecoratedPropertyMember(node)) {
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return;
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}
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var bindExpression = node.expression;
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if (!isBindPropertyAccess(bindExpression)) {
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return;
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}
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var boundExpression = Lint.unwrapParentheses(bindExpression.expression);
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if (tsutils.isFunctionExpression(boundExpression)) {
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checkFunctionExpression(node, boundExpression);
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return;
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}
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var valueDeclaration = getArrowFunctionDeclaration(boundExpression);
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if (valueDeclaration !== undefined) {
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checkArrowFunction(node);
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}
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}
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return ts.forEachChild(context.sourceFile, function callback(node) {
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if (ts.isCallExpression(node)) {
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checkCallExpression(node);
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}
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return ts.forEachChild(node, callback);
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});
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}
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function isBindPropertyAccess(node) {
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return ts.isPropertyAccessExpression(node) && node.name.text === "bind";
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}
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var templateObject_1;
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