98 lines
4.6 KiB
JavaScript
98 lines
4.6 KiB
JavaScript
"use strict";
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/**
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* @license
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* Copyright 2019 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 TAUTOLOGY_DISCOVERED_ERROR_STRING = "Both sides of this equality comparison are the same, so the expression is either a tautology or a contradiction.";
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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.metadata = {
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description: Lint.Utils.dedent(templateObject_1 || (templateObject_1 = tslib_1.__makeTemplateObject(["\n Enforces that relational/equality binary operators does not take two equal variables/literals as operands.\n Expression like 3 === 3, someVar === someVar, \"1\" > \"1\" are either a tautology or contradiction, and will produce an error.\n "], ["\n Enforces that relational/equality binary operators does not take two equal variables/literals as operands.\n Expression like 3 === 3, someVar === someVar, \"1\" > \"1\" are either a tautology or contradiction, and will produce an error.\n "]))),
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optionExamples: [true],
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options: null,
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optionsDescription: "Not configurable.",
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rationale: "Clean redundant code and unnecessary comparison of objects and literals.",
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ruleName: "no-tautology-expression",
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type: "functionality",
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typescriptOnly: false,
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};
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return Rule;
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}(Lint.Rules.AbstractRule));
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exports.Rule = Rule;
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function walk(context) {
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var cb = function (node) {
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if (tsutils.isBinaryExpression(node) && isRelationalOrLogicalOperator(node.operatorToken)) {
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if ((tsutils.isStringLiteral(node.left) && tsutils.isStringLiteral(node.right)) ||
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(tsutils.isNumericLiteral(node.left) && tsutils.isNumericLiteral(node.right))) {
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if (node.left.text === node.right.text) {
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context.addFailureAtNode(node, TAUTOLOGY_DISCOVERED_ERROR_STRING);
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}
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}
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else if (tsutils.isIdentifier(node.left) && tsutils.isIdentifier(node.right)) {
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if (node.left.text === node.right.text) {
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context.addFailureAtNode(node, TAUTOLOGY_DISCOVERED_ERROR_STRING);
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}
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}
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else if (tsutils.isPropertyAccessExpression(node.left) &&
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tsutils.isPropertyAccessExpression(node.right)) {
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if (node.left.expression.getText() === node.right.expression.getText()) {
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if (node.left.name.text === node.right.name.text) {
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context.addFailureAtNode(node, TAUTOLOGY_DISCOVERED_ERROR_STRING);
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}
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}
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}
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else if ((isBooleanLiteral(node.left) && isBooleanLiteral(node.right)) ||
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(isNullLiteral(node.left) && isNullLiteral(node.right))) {
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context.addFailureAtNode(node, TAUTOLOGY_DISCOVERED_ERROR_STRING);
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}
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}
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return ts.forEachChild(node, cb);
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};
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return ts.forEachChild(context.sourceFile, cb);
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}
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function isNullLiteral(node) {
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return node.kind === ts.SyntaxKind.NullKeyword;
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}
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function isBooleanLiteral(node) {
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return node.kind === ts.SyntaxKind.TrueKeyword || node.kind === ts.SyntaxKind.FalseKeyword;
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}
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function isRelationalOrLogicalOperator(operator) {
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return new Set([
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ts.SyntaxKind.LessThanToken,
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ts.SyntaxKind.GreaterThanToken,
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ts.SyntaxKind.LessThanEqualsToken,
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ts.SyntaxKind.GreaterThanEqualsToken,
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ts.SyntaxKind.EqualsEqualsToken,
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ts.SyntaxKind.EqualsEqualsEqualsToken,
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ts.SyntaxKind.ExclamationEqualsToken,
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ts.SyntaxKind.ExclamationEqualsEqualsToken,
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ts.SyntaxKind.AmpersandAmpersandToken,
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ts.SyntaxKind.BarBarToken,
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]).has(operator.kind);
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}
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var templateObject_1;
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