94 lines
3.8 KiB
JavaScript
94 lines
3.8 KiB
JavaScript
|
"use strict";
|
||
|
|
/**
|
||
|
|
* @license
|
||
|
|
* Copyright 2017 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.
|
||
|
|
*/
|
||
|
|
Object.defineProperty(exports, "__esModule", { value: true });
|
||
|
|
var tslib_1 = require("tslib");
|
||
|
|
var tsutils_1 = require("tsutils");
|
||
|
|
var ts = require("typescript");
|
||
|
|
var Lint = require("../index");
|
||
|
|
var utils_1 = require("../language/utils");
|
||
|
|
var Rule = (function (_super) {
|
||
|
|
tslib_1.__extends(Rule, _super);
|
||
|
|
function Rule() {
|
||
|
|
return _super !== null && _super.apply(this, arguments) || this;
|
||
|
|
}
|
||
|
|
Rule.prototype.apply = function (sourceFile) {
|
||
|
|
return this.applyWithFunction(sourceFile, walk);
|
||
|
|
};
|
||
|
|
/* tslint:disable:object-literal-sort-keys */
|
||
|
|
Rule.metadata = {
|
||
|
|
ruleName: "binary-expression-operand-order",
|
||
|
|
description: (_a = ["\n In a binary expression, a literal should always be on the right-hand side if possible.\n For example, prefer 'x + 1' over '1 + x'."], _a.raw = ["\n In a binary expression, a literal should always be on the right-hand side if possible.\n For example, prefer 'x + 1' over '1 + x'."], Lint.Utils.dedent(_a)),
|
||
|
|
optionsDescription: "Not configurable.",
|
||
|
|
options: null,
|
||
|
|
optionExamples: [true],
|
||
|
|
type: "style",
|
||
|
|
typescriptOnly: false,
|
||
|
|
};
|
||
|
|
/* tslint:enable:object-literal-sort-keys */
|
||
|
|
Rule.FAILURE_STRING = "Literal expression should be on the right-hand side of a binary expression.";
|
||
|
|
return Rule;
|
||
|
|
}(Lint.Rules.AbstractRule));
|
||
|
|
exports.Rule = Rule;
|
||
|
|
function walk(ctx) {
|
||
|
|
ts.forEachChild(ctx.sourceFile, function cb(node) {
|
||
|
|
if (tsutils_1.isBinaryExpression(node) && isLiteral(node.left) && !isLiteral(node.right) && !isAllowedOrderedOperator(node)) {
|
||
|
|
ctx.addFailureAtNode(node, Rule.FAILURE_STRING);
|
||
|
|
}
|
||
|
|
ts.forEachChild(node, cb);
|
||
|
|
});
|
||
|
|
}
|
||
|
|
/** Allows certain inherently ordered operators that can't easily be written with the literal on the right. */
|
||
|
|
function isAllowedOrderedOperator(node) {
|
||
|
|
switch (node.operatorToken.kind) {
|
||
|
|
case ts.SyntaxKind.PlusToken:
|
||
|
|
// Allow `"foo" + x` but not `1 + x`.
|
||
|
|
return node.left.kind === ts.SyntaxKind.StringLiteral;
|
||
|
|
case ts.SyntaxKind.MinusToken:
|
||
|
|
case ts.SyntaxKind.SlashToken:
|
||
|
|
case ts.SyntaxKind.PercentToken:
|
||
|
|
case ts.SyntaxKind.LessThanLessThanToken:
|
||
|
|
case ts.SyntaxKind.GreaterThanGreaterThanToken:
|
||
|
|
case ts.SyntaxKind.GreaterThanGreaterThanGreaterThanToken:
|
||
|
|
case ts.SyntaxKind.AsteriskAsteriskToken:
|
||
|
|
case ts.SyntaxKind.InKeyword:
|
||
|
|
case ts.SyntaxKind.CommaToken:
|
||
|
|
return true;
|
||
|
|
default:
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
function isLiteral(node) {
|
||
|
|
switch (node.kind) {
|
||
|
|
case ts.SyntaxKind.StringLiteral:
|
||
|
|
case ts.SyntaxKind.NumericLiteral:
|
||
|
|
case ts.SyntaxKind.TrueKeyword:
|
||
|
|
case ts.SyntaxKind.FalseKeyword:
|
||
|
|
case ts.SyntaxKind.NullKeyword:
|
||
|
|
return true;
|
||
|
|
case ts.SyntaxKind.Identifier:
|
||
|
|
return node.originalKeywordKind === ts.SyntaxKind.UndefinedKeyword;
|
||
|
|
case ts.SyntaxKind.PrefixUnaryExpression:
|
||
|
|
return utils_1.isNegativeNumberLiteral(node);
|
||
|
|
case ts.SyntaxKind.ParenthesizedExpression:
|
||
|
|
return isLiteral(node.expression);
|
||
|
|
default:
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
var _a;
|