336 lines
16 KiB
JavaScript
336 lines
16 KiB
JavaScript
"use strict";
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/**
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* @license
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* Copyright 2016 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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var tslib_1 = require("tslib");
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var ts = require("typescript");
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var Lint = require("../index");
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var OPTION_ALLOW_NULL_UNION = "allow-null-union";
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var OPTION_ALLOW_UNDEFINED_UNION = "allow-undefined-union";
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var OPTION_ALLOW_STRING = "allow-string";
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var OPTION_ALLOW_NUMBER = "allow-number";
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var OPTION_ALLOW_MIX = "allow-mix";
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// tslint:disable object-literal-sort-keys switch-default
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var Rule = (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.applyWithProgram = function (sourceFile, program) {
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var options = parseOptions(this.ruleArguments, program.getCompilerOptions().strictNullChecks === true);
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return this.applyWithFunction(sourceFile, function (ctx) { return walk(ctx, program.getTypeChecker()); }, options);
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};
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return Rule;
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}(Lint.Rules.TypedRule));
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Rule.metadata = {
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ruleName: "strict-boolean-expressions",
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description: (_a = ["\n Restricts the types allowed in boolean expressions. By default only booleans are allowed.\n\n The following nodes are checked:\n\n * Arguments to the `!`, `&&`, and `||` operators\n * The condition in a conditional expression (`cond ? x : y`)\n * Conditions for `if`, `for`, `while`, and `do-while` statements."], _a.raw = ["\n Restricts the types allowed in boolean expressions. By default only booleans are allowed.\n\n The following nodes are checked:\n\n * Arguments to the \\`!\\`, \\`&&\\`, and \\`||\\` operators\n * The condition in a conditional expression (\\`cond ? x : y\\`)\n * Conditions for \\`if\\`, \\`for\\`, \\`while\\`, and \\`do-while\\` statements."], Lint.Utils.dedent(_a)),
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optionsDescription: (_b = ["\n These options may be provided:\n\n * `", "` allows union types containing `null`.\n - It does *not* allow `null` itself.\n - Without the '--strictNullChecks' compiler option, this will allow anything other than a string, number, or enum.\n * `", "` allows union types containing `undefined`.\n - It does *not* allow `undefined` itself.\n - Without the '--strictNullChecks' compiler option, this will allow anything other than a string, number, or enum.\n * `", "` allows strings.\n - It does *not* allow unions containing `string`.\n - It does *not* allow string literal types.\n * `", "` allows numbers.\n - It does *not* allow unions containing `number`.\n - It does *not* allow enums or number literal types.\n * `", "` allow multiple of the above to appear together.\n - For example, `string | number` or `RegExp | null | undefined` would normally not be allowed.\n - A type like `\"foo\" | \"bar\" | undefined` is always allowed, because it has only one way to be false."], _b.raw = ["\n These options may be provided:\n\n * \\`", "\\` allows union types containing \\`null\\`.\n - It does *not* allow \\`null\\` itself.\n - Without the '--strictNullChecks' compiler option, this will allow anything other than a string, number, or enum.\n * \\`", "\\` allows union types containing \\`undefined\\`.\n - It does *not* allow \\`undefined\\` itself.\n - Without the '--strictNullChecks' compiler option, this will allow anything other than a string, number, or enum.\n * \\`", "\\` allows strings.\n - It does *not* allow unions containing \\`string\\`.\n - It does *not* allow string literal types.\n * \\`", "\\` allows numbers.\n - It does *not* allow unions containing \\`number\\`.\n - It does *not* allow enums or number literal types.\n * \\`", "\\` allow multiple of the above to appear together.\n - For example, \\`string | number\\` or \\`RegExp | null | undefined\\` would normally not be allowed.\n - A type like \\`\"foo\" | \"bar\" | undefined\\` is always allowed, because it has only one way to be false."], Lint.Utils.dedent(_b, OPTION_ALLOW_NULL_UNION, OPTION_ALLOW_UNDEFINED_UNION, OPTION_ALLOW_STRING, OPTION_ALLOW_NUMBER, OPTION_ALLOW_MIX)),
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options: {
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type: "array",
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items: {
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type: "string",
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enum: [OPTION_ALLOW_NULL_UNION, OPTION_ALLOW_UNDEFINED_UNION, OPTION_ALLOW_STRING, OPTION_ALLOW_NUMBER],
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},
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minLength: 0,
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maxLength: 5,
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},
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optionExamples: [
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true,
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[true, OPTION_ALLOW_NULL_UNION, OPTION_ALLOW_UNDEFINED_UNION, OPTION_ALLOW_STRING, OPTION_ALLOW_NUMBER],
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],
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type: "functionality",
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typescriptOnly: true,
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requiresTypeInfo: true,
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};
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exports.Rule = Rule;
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function parseOptions(ruleArguments, strictNullChecks) {
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return {
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strictNullChecks: strictNullChecks,
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allowNullUnion: has(OPTION_ALLOW_NULL_UNION),
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allowUndefinedUnion: has(OPTION_ALLOW_UNDEFINED_UNION),
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allowString: has(OPTION_ALLOW_STRING),
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allowNumber: has(OPTION_ALLOW_NUMBER),
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allowMix: has(OPTION_ALLOW_MIX),
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};
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function has(name) {
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return ruleArguments.indexOf(name) !== -1;
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}
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}
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function walk(ctx, checker) {
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var sourceFile = ctx.sourceFile, options = ctx.options;
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ts.forEachChild(sourceFile, function cb(node) {
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switch (node.kind) {
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case ts.SyntaxKind.BinaryExpression: {
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var b_1 = node;
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if (binaryBooleanExpressionKind(b_1) !== undefined) {
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var left = b_1.left, right = b_1.right;
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var checkHalf = function (expr) {
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// If it's another boolean binary expression, we'll check it when recursing.
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if (!isBooleanBinaryExpression(expr)) {
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checkExpression(expr, b_1);
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}
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};
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checkHalf(left);
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checkHalf(right);
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}
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break;
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}
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case ts.SyntaxKind.PrefixUnaryExpression: {
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var _a = node, operator = _a.operator, operand = _a.operand;
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if (operator === ts.SyntaxKind.ExclamationToken) {
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checkExpression(operand, node);
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}
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break;
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}
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case ts.SyntaxKind.IfStatement:
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case ts.SyntaxKind.WhileStatement:
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case ts.SyntaxKind.DoStatement: {
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var c = node;
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// If it's a boolean binary expression, we'll check it when recursing.
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if (!isBooleanBinaryExpression(c.expression)) {
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checkExpression(c.expression, c);
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}
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break;
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}
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case ts.SyntaxKind.ConditionalExpression:
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checkExpression(node.condition, node);
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break;
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case ts.SyntaxKind.ForStatement: {
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var condition = node.condition;
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if (condition !== undefined) {
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checkExpression(condition, node);
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}
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break;
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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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function checkExpression(node, location) {
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var type = checker.getTypeAtLocation(node);
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var failure = getTypeFailure(type, options);
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if (failure !== undefined) {
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if (failure === 0 /* AlwaysTruthy */ &&
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!options.strictNullChecks &&
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(options.allowNullUnion || options.allowUndefinedUnion)) {
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// OK; It might be null/undefined.
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return;
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}
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ctx.addFailureAtNode(node, showFailure(location, failure, isUnionType(type), options));
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}
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}
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}
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function getTypeFailure(type, options) {
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if (isUnionType(type)) {
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return handleUnion(type, options);
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}
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var kind = getKind(type);
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var failure = failureForKind(kind, /*isInUnion*/ false, options);
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if (failure !== undefined) {
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return failure;
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}
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switch (triState(kind)) {
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case true:
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return 0 /* AlwaysTruthy */;
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case false:
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return 1 /* AlwaysFalsy */;
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case undefined:
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return undefined;
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}
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}
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function handleUnion(type, options) {
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// Tracks whether it's possibly truthy.
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var anyTruthy = false;
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// Counts falsy kinds to see if there's a mix. Also tracks whether it's possibly falsy.
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var seenFalsy = 0;
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for (var _i = 0, _a = type.types; _i < _a.length; _i++) {
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var ty = _a[_i];
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var kind = getKind(ty);
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var failure = failureForKind(kind, /*isInUnion*/ true, options);
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if (failure !== undefined) {
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return failure;
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}
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switch (triState(kind)) {
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case true:
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anyTruthy = true;
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break;
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case false:
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seenFalsy++;
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break;
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default:
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anyTruthy = true;
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seenFalsy++;
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}
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}
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return seenFalsy === 0 ? 0 /* AlwaysTruthy */
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: !anyTruthy ? 1 /* AlwaysFalsy */
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: !options.allowMix && seenFalsy > 1 ? 7 /* Mixes */ : undefined;
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}
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/** Fails if a kind of falsiness is not allowed. */
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function failureForKind(kind, isInUnion, options) {
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switch (kind) {
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case 0 /* String */:
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case 1 /* FalseStringLiteral */:
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return options.allowString ? undefined : 2 /* String */;
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case 2 /* Number */:
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case 3 /* FalseNumberLiteral */:
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return options.allowNumber ? undefined : 3 /* Number */;
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case 8 /* Enum */:
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return 6 /* Enum */;
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case 6 /* Null */:
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return isInUnion && !options.allowNullUnion ? 4 /* Null */ : undefined;
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case 7 /* Undefined */:
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return isInUnion && !options.allowUndefinedUnion ? 5 /* Undefined */ : undefined;
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default:
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return undefined;
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}
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}
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/** Divides a type into always true, always false, or unknown. */
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function triState(kind) {
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switch (kind) {
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case 0 /* String */:
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case 2 /* Number */:
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case 4 /* Boolean */:
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case 8 /* Enum */:
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return undefined;
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case 6 /* Null */:
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case 7 /* Undefined */:
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case 3 /* FalseNumberLiteral */:
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case 1 /* FalseStringLiteral */:
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case 5 /* FalseBooleanLiteral */:
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return false;
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case 9 /* AlwaysTruthy */:
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return true;
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}
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}
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function getKind(type) {
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return is(ts.TypeFlags.String) ? 0 /* String */
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: is(ts.TypeFlags.Number) ? 2 /* Number */
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: is(ts.TypeFlags.Boolean) ? 4 /* Boolean */
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: is(ts.TypeFlags.Null) ? 6 /* Null */
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: is(ts.TypeFlags.Undefined | ts.TypeFlags.Void) ? 7 /* Undefined */
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: is(ts.TypeFlags.EnumLike) ? 8 /* Enum */
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: is(ts.TypeFlags.NumberLiteral) ?
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(numberLiteralIsZero(type) ? 3 /* FalseNumberLiteral */ : 9 /* AlwaysTruthy */)
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: is(ts.TypeFlags.StringLiteral) ?
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(stringLiteralIsEmpty(type) ? 1 /* FalseStringLiteral */ : 9 /* AlwaysTruthy */)
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: is(ts.TypeFlags.BooleanLiteral) ?
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(type.intrinsicName === "true" ? 9 /* AlwaysTruthy */ : 5 /* FalseBooleanLiteral */)
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: 9 /* AlwaysTruthy */;
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function is(flags) {
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return Lint.isTypeFlagSet(type, flags);
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}
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}
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function numberLiteralIsZero(type) {
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// Uses 'value' in TypeScript>=2.4.
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return type.value !== undefined ? type.value === 0 : type.text === "0";
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}
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function stringLiteralIsEmpty(type) {
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return (type.value !== undefined ? type.value : type.text) === "";
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}
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/** Matches `&&` and `||` operators. */
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function isBooleanBinaryExpression(node) {
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return node.kind === ts.SyntaxKind.BinaryExpression && binaryBooleanExpressionKind(node) !== undefined;
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}
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function binaryBooleanExpressionKind(node) {
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switch (node.operatorToken.kind) {
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case ts.SyntaxKind.AmpersandAmpersandToken:
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return "&&";
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case ts.SyntaxKind.BarBarToken:
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return "||";
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default:
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return undefined;
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}
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}
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function stringOr(parts) {
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switch (parts.length) {
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case 1:
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return parts[0];
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case 2:
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return parts[0] + " or " + parts[1];
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default:
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var res = "";
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for (var i = 0; i < parts.length - 1; i++) {
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res += parts[i] + ", ";
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}
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return res + "or " + parts[parts.length - 1];
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}
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}
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function isUnionType(type) {
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return Lint.isTypeFlagSet(type, ts.TypeFlags.Union) && !Lint.isTypeFlagSet(type, ts.TypeFlags.Enum);
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}
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function showLocation(n) {
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switch (n.kind) {
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case ts.SyntaxKind.PrefixUnaryExpression:
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return "operand for the '!' operator";
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case ts.SyntaxKind.ConditionalExpression:
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return "condition";
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case ts.SyntaxKind.ForStatement:
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return "'for' condition";
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case ts.SyntaxKind.IfStatement:
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return "'if' condition";
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case ts.SyntaxKind.WhileStatement:
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return "'while' condition";
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case ts.SyntaxKind.DoStatement:
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return "'do-while' condition";
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case ts.SyntaxKind.BinaryExpression:
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return "operand for the '" + binaryBooleanExpressionKind(n) + "' operator";
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}
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}
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function showFailure(location, ty, isUnionType, options) {
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var expectedTypes = showExpectedTypes(options);
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var expected = expectedTypes.length === 1
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? "Only " + expectedTypes[0] + "s are allowed"
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: "Allowed types are " + stringOr(expectedTypes);
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var tyFail = showTypeFailure(ty, isUnionType, options.strictNullChecks);
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return "This type is not allowed in the " + showLocation(location) + " because it " + tyFail + ". " + expected + ".";
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}
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function showExpectedTypes(options) {
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var parts = ["boolean"];
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if (options.allowNullUnion) {
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parts.push("null-union");
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}
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if (options.allowUndefinedUnion) {
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parts.push("undefined-union");
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}
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if (options.allowString) {
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parts.push("string");
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}
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if (options.allowNumber) {
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parts.push("number");
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}
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return parts;
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}
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function showTypeFailure(ty, isUnionType, strictNullChecks) {
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var is = isUnionType ? "could be" : "is";
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switch (ty) {
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case 0 /* AlwaysTruthy */:
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return strictNullChecks
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? "is always truthy"
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: "is always truthy. It may be null/undefined, but neither " +
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("'" + OPTION_ALLOW_NULL_UNION + "' nor '" + OPTION_ALLOW_UNDEFINED_UNION + "' is set");
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case 1 /* AlwaysFalsy */: return "is always falsy";
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case 2 /* String */: return is + " a string";
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case 3 /* Number */: return is + " a number";
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case 4 /* Null */: return is + " null";
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case 5 /* Undefined */: return is + " undefined";
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case 6 /* Enum */: return is + " an enum";
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case 7 /* Mixes */: return "unions more than one truthy/falsy type";
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}
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}
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var _a, _b;
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