"use strict";
/**
* @license
* Copyright 2019 Palantir Technologies, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
var _a, _b, _c;
Object.defineProperty(exports, "__esModule", { value: true });
exports.Rule = void 0;
var tslib_1 = require("tslib");
var tsutils_1 = require("tsutils");
var ts = require("typescript");
var Lint = require("../index");
var strictComparisons_examples_1 = require("./code-examples/strictComparisons.examples");
var OPTION_ALLOW_OBJECT_EQUAL_COMPARISON = "allow-object-equal-comparison";
var OPTION_ALLOW_STRING_ORDER_COMPARISON = "allow-string-order-comparison";
var typeNames = (_a = {},
_a[0 /* Any */] = "any",
_a[1 /* Number */] = "number",
_a[2 /* Enum */] = "enum",
_a[3 /* String */] = "string",
_a[4 /* Boolean */] = "boolean",
_a[5 /* Null */] = "null",
_a[6 /* Undefined */] = "undefined",
_a[7 /* Object */] = "object",
_a);
var Rule = /** @class */ (function (_super) {
tslib_1.__extends(Rule, _super);
function Rule() {
return _super !== null && _super.apply(this, arguments) || this;
}
/* tslint:enable:object-literal-sort-keys */
Rule.INVALID_TYPES = function (types1, types2) {
var types1String = types1.map(function (type) { return typeNames[type]; }).join(" | ");
var types2String = types2.map(function (type) { return typeNames[type]; }).join(" | ");
return "Cannot compare type '" + types1String + "' to type '" + types2String + "'.";
};
Rule.INVALID_TYPE_FOR_OPERATOR = function (type, comparator) {
return "Cannot use '" + comparator + "' comparator for type '" + typeNames[type] + "'.";
};
Rule.prototype.applyWithProgram = function (sourceFile, program) {
return this.applyWithFunction(sourceFile, walk, this.getRuleOptions(), program);
};
Rule.prototype.getRuleOptions = function () {
if (this.ruleArguments[0] === undefined) {
return {};
}
else {
return this.ruleArguments[0];
}
};
/* tslint:disable:object-literal-sort-keys */
Rule.metadata = {
ruleName: "strict-comparisons",
description: "Only allow comparisons between primitives.",
optionsDescription: Lint.Utils.dedent(templateObject_1 || (templateObject_1 = tslib_1.__makeTemplateObject(["\n One of the following arguments may be optionally provided:\n * `", "` allows `!=` `==` `!==` `===` comparison between any types.\n * `", "` allows `>` `<` `>=` `<=` comparison between strings."], ["\n One of the following arguments may be optionally provided:\n * \\`", "\\` allows \\`!=\\` \\`==\\` \\`!==\\` \\`===\\` comparison between any types.\n * \\`", "\\` allows \\`>\\` \\`<\\` \\`>=\\` \\`<=\\` comparison between strings."])), OPTION_ALLOW_OBJECT_EQUAL_COMPARISON, OPTION_ALLOW_STRING_ORDER_COMPARISON),
options: {
type: "object",
properties: (_b = {},
_b[OPTION_ALLOW_OBJECT_EQUAL_COMPARISON] = {
type: "boolean",
},
_b[OPTION_ALLOW_STRING_ORDER_COMPARISON] = {
type: "boolean",
},
_b),
},
optionExamples: [
true,
[
true,
(_c = {},
_c[OPTION_ALLOW_OBJECT_EQUAL_COMPARISON] = false,
_c[OPTION_ALLOW_STRING_ORDER_COMPARISON] = false,
_c),
],
],
rationale: Lint.Utils.dedent(templateObject_2 || (templateObject_2 = tslib_1.__makeTemplateObject(["\n When using comparison operators to compare objects, they compare references and not values.\n This is often done accidentally.\n With this rule, `>`, `>=`, `<`, `<=` operators are only allowed when comparing `numbers`.\n `===`, `!==` are allowed for `number` `string` and `boolean` types and if one of the\n operands is `null` or `undefined`.\n "], ["\n When using comparison operators to compare objects, they compare references and not values.\n This is often done accidentally.\n With this rule, \\`>\\`, \\`>=\\`, \\`<\\`, \\`<=\\` operators are only allowed when comparing \\`numbers\\`.\n \\`===\\`, \\`!==\\` are allowed for \\`number\\` \\`string\\` and \\`boolean\\` types and if one of the\n operands is \\`null\\` or \\`undefined\\`.\n "]))),
type: "functionality",
typescriptOnly: false,
requiresTypeInfo: true,
codeExamples: strictComparisons_examples_1.codeExamples,
};
return Rule;
}(Lint.Rules.TypedRule));
exports.Rule = Rule;
function walk(ctx, program) {
var sourceFile = ctx.sourceFile, options = ctx.options;
var checker = program.getTypeChecker();
return ts.forEachChild(sourceFile, function cb(node) {
if (tsutils_1.isBinaryExpression(node) && isComparisonOperator(node)) {
var isEquality = isEqualityOperator(node);
var leftType = checker.getTypeAtLocation(node.left);
var rightType = checker.getTypeAtLocation(node.right);
if ((containsNullOrUndefined(leftType) || containsNullOrUndefined(rightType)) &&
isEquality) {
return;
}
var leftKinds = getTypes(leftType);
var rightKinds = getTypes(rightType);
var operandKind = getStrictestComparableType(leftKinds, rightKinds);
if (operandKind === undefined) {
var failureString = Rule.INVALID_TYPES(leftKinds, rightKinds);
ctx.addFailureAtNode(node, failureString);
}
else {
var failureString = Rule.INVALID_TYPE_FOR_OPERATOR(operandKind, node.operatorToken.getText());
if (isEquality) {
// Check !=, ==, !==, ===
switch (operandKind) {
case 0 /* Any */:
case 1 /* Number */:
case 2 /* Enum */:
case 3 /* String */:
case 4 /* Boolean */:
break;
case 5 /* Null */:
case 6 /* Undefined */:
case 7 /* Object */:
if (options[OPTION_ALLOW_OBJECT_EQUAL_COMPARISON]) {
break;
}
ctx.addFailureAtNode(node, failureString);
break;
default:
ctx.addFailureAtNode(node, failureString);
}
}
else {
// Check >, <, >=, <=
switch (operandKind) {
case 0 /* Any */:
case 1 /* Number */:
break;
case 3 /* String */:
if (options[OPTION_ALLOW_STRING_ORDER_COMPARISON]) {
break;
}
ctx.addFailureAtNode(node, failureString);
break;
default:
ctx.addFailureAtNode(node, failureString);
}
}
}
}
return ts.forEachChild(node, cb);
});
}
function containsNullOrUndefined(type) {
return (type.intrinsicName === "null" ||
type.intrinsicName === "undefined");
}
function getTypes(types) {
// Compatibility for TypeScript pre-2.4, which used EnumLiteralType instead of LiteralType
var baseType = types.baseType;
return tsutils_1.isUnionType(types)
? Array.from(new Set(types.types.map(getKind)))
: tsutils_1.isTypeFlagSet(types, ts.TypeFlags.EnumLiteral) && typeof baseType !== "undefined"
? [getKind(baseType)]
: [getKind(types)];
}
function getStrictestComparableType(typesLeft, typesRight) {
var overlappingTypes = typesLeft.filter(function (type) { return typesRight.indexOf(type) >= 0; });
if (overlappingTypes.length > 0) {
return getStrictestKind(overlappingTypes);
}
else {
// In case one of the types is "any", get the strictest type of the other array
if (arrayContainsKind(typesLeft, [0 /* Any */])) {
return getStrictestKind(typesRight);
}
if (arrayContainsKind(typesRight, [0 /* Any */])) {
return getStrictestKind(typesLeft);
}
// In case one array contains NullOrUndefined and the other an Object, return Object
if ((arrayContainsKind(typesLeft, [5 /* Null */, 6 /* Undefined */]) &&
arrayContainsKind(typesRight, [7 /* Object */])) ||
(arrayContainsKind(typesRight, [5 /* Null */, 6 /* Undefined */]) &&
arrayContainsKind(typesLeft, [7 /* Object */]))) {
return 7 /* Object */;
}
return undefined;
}
}
function arrayContainsKind(types, typeToCheck) {
return types.some(function (type) { return typeToCheck.indexOf(type) >= 0; });
}
function getStrictestKind(types) {
// tslint:disable-next-line:no-unsafe-any
return Math.max.apply(Math, types);
}
function isComparisonOperator(node) {
switch (node.operatorToken.kind) {
case ts.SyntaxKind.LessThanToken:
case ts.SyntaxKind.GreaterThanToken:
case ts.SyntaxKind.LessThanEqualsToken:
case ts.SyntaxKind.GreaterThanEqualsToken:
case ts.SyntaxKind.EqualsEqualsToken:
case ts.SyntaxKind.ExclamationEqualsToken:
case ts.SyntaxKind.EqualsEqualsEqualsToken:
case ts.SyntaxKind.ExclamationEqualsEqualsToken:
return true;
default:
return false;
}
}
function isEqualityOperator(node) {
switch (node.operatorToken.kind) {
case ts.SyntaxKind.EqualsEqualsToken:
case ts.SyntaxKind.ExclamationEqualsToken:
case ts.SyntaxKind.EqualsEqualsEqualsToken:
case ts.SyntaxKind.ExclamationEqualsEqualsToken:
return true;
default:
return false;
}
}
function getKind(type) {
// tslint:disable:no-bitwise
if (is(ts.TypeFlags.String | ts.TypeFlags.StringLiteral)) {
return 3 /* String */;
}
else if (is(ts.TypeFlags.Number | ts.TypeFlags.NumberLiteral)) {
return 1 /* Number */;
}
else if (is(ts.TypeFlags.BooleanLike)) {
return 4 /* Boolean */;
}
else if (is(ts.TypeFlags.Null)) {
return 5 /* Null */;
}
else if (is(ts.TypeFlags.Undefined)) {
return 6 /* Undefined */;
}
else if (is(ts.TypeFlags.Any)) {
return 0 /* Any */;
}
else {
return 7 /* Object */;
}
// tslint:enable:no-bitwise
function is(flags) {
return tsutils_1.isTypeFlagSet(type, flags);
}
}
var templateObject_1, templateObject_2;