125 lines
5.2 KiB
JavaScript
125 lines
5.2 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 Rule = /** @class */ (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: "prefer-object-spread",
|
|
description: "Enforces the use of the ES2015 object spread operator over `Object.assign()` where appropriate.",
|
|
rationale: "Object spread allows for better type checking and inference.",
|
|
optionsDescription: "Not configurable.",
|
|
options: null,
|
|
optionExamples: [true],
|
|
type: "functionality",
|
|
typescriptOnly: false,
|
|
hasFix: true,
|
|
};
|
|
/* tslint:enable:object-literal-sort-keys */
|
|
Rule.FAILURE_STRING = "Use the object spread operator instead.";
|
|
Rule.ASSIGNMENT_FAILURE_STRING = "'Object.assign' returns the first argument. Prefer object spread if you want a new object.";
|
|
return Rule;
|
|
}(Lint.Rules.AbstractRule));
|
|
exports.Rule = Rule;
|
|
function walk(ctx) {
|
|
return ts.forEachChild(ctx.sourceFile, function cb(node) {
|
|
if (tsutils_1.isCallExpression(node) && node.arguments.length !== 0 &&
|
|
tsutils_1.isPropertyAccessExpression(node.expression) && node.expression.name.text === "assign" &&
|
|
tsutils_1.isIdentifier(node.expression.expression) && node.expression.expression.text === "Object" &&
|
|
!ts.isFunctionLike(node.arguments[0]) &&
|
|
// Object.assign(...someArray) cannot be written as object spread
|
|
!node.arguments.some(tsutils_1.isSpreadElement) &&
|
|
/**
|
|
* @TODO
|
|
* Remove !node.arguments.some(isThisKeyword) when typescript get's
|
|
* support for spread types.
|
|
* PR: https://github.com/Microsoft/TypeScript/issues/10727
|
|
*/
|
|
!node.arguments.some(isThisKeyword)) {
|
|
if (node.arguments[0].kind === ts.SyntaxKind.ObjectLiteralExpression) {
|
|
ctx.addFailureAtNode(node, Rule.FAILURE_STRING, createFix(node, ctx.sourceFile));
|
|
}
|
|
else if (tsutils_1.isExpressionValueUsed(node) && !tsutils_1.hasSideEffects(node.arguments[0], 2 /* Constructor */)) {
|
|
ctx.addFailureAtNode(node, Rule.ASSIGNMENT_FAILURE_STRING, createFix(node, ctx.sourceFile));
|
|
}
|
|
}
|
|
return ts.forEachChild(node, cb);
|
|
});
|
|
}
|
|
function createFix(node, sourceFile) {
|
|
var args = node.arguments;
|
|
var objectNeedsParens = node.parent.kind === ts.SyntaxKind.ArrowFunction;
|
|
var fix = [
|
|
Lint.Replacement.replaceFromTo(node.getStart(sourceFile), args[0].getStart(sourceFile), (objectNeedsParens ? "(" : "") + "{"),
|
|
new Lint.Replacement(node.end - 1, 1, "}" + (objectNeedsParens ? ")" : "")),
|
|
];
|
|
for (var i = 0; i < args.length; ++i) {
|
|
var arg = args[i];
|
|
if (tsutils_1.isObjectLiteralExpression(arg)) {
|
|
if (arg.properties.length === 0) {
|
|
var end = arg.end;
|
|
if (i !== args.length - 1) {
|
|
end = args[i + 1].getStart(sourceFile);
|
|
}
|
|
else if (args.hasTrailingComma) {
|
|
end = args.end;
|
|
}
|
|
// remove empty object iteral and the following comma if exists
|
|
fix.push(Lint.Replacement.deleteFromTo(arg.getStart(sourceFile), end));
|
|
}
|
|
else {
|
|
fix.push(
|
|
// remove open brace
|
|
Lint.Replacement.deleteText(arg.getStart(sourceFile), 1),
|
|
// remove trailing comma if exists and close brace
|
|
Lint.Replacement.deleteFromTo(arg.properties[arg.properties.length - 1].end, arg.end));
|
|
}
|
|
}
|
|
else {
|
|
var parens = needsParens(arg);
|
|
fix.push(Lint.Replacement.appendText(arg.getStart(sourceFile), parens ? "...(" : "..."));
|
|
if (parens) {
|
|
fix.push(Lint.Replacement.appendText(arg.end, ")"));
|
|
}
|
|
}
|
|
}
|
|
return fix;
|
|
}
|
|
function isThisKeyword(node) {
|
|
return node.kind === ts.SyntaxKind.ThisKeyword;
|
|
}
|
|
function needsParens(node) {
|
|
switch (node.kind) {
|
|
case ts.SyntaxKind.ConditionalExpression:
|
|
case ts.SyntaxKind.BinaryExpression:
|
|
return true;
|
|
default:
|
|
return false;
|
|
}
|
|
}
|