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"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 utils = require("tsutils");
var ts = require("typescript");
var Lint = require("../index");
var utils_1 = require("../language/utils");
var OPTION_MULTILINE = "multiline";
var Rule = (function (_super) {
tslib_1.__extends(Rule, _super);
function Rule() {
return _super !== null && _super.apply(this, arguments) || this;
}
/* tslint:enable:object-literal-sort-keys */
Rule.FAILURE_STRING = function (isObjectLiteral) {
var start = "This arrow function body can be simplified by omitting the curly braces and the keyword 'return'";
return start + (isObjectLiteral ? ", and wrapping the object literal in parentheses." : ".");
};
Rule.prototype.apply = function (sourceFile) {
return this.applyWithFunction(sourceFile, walk, { multiline: this.ruleArguments.indexOf(OPTION_MULTILINE) !== -1 });
};
return Rule;
}(Lint.Rules.AbstractRule));
/* tslint:disable:object-literal-sort-keys */
Rule.metadata = {
ruleName: "arrow-return-shorthand",
description: "Suggests to convert `() => { return x; }` to `() => x`.",
hasFix: true,
optionsDescription: (_a = ["\n If `", "` is specified, then this will warn even if the function spans multiple lines."], _a.raw = ["\n If \\`", "\\` is specified, then this will warn even if the function spans multiple lines."], Lint.Utils.dedent(_a, OPTION_MULTILINE)),
options: {
type: "string",
enum: [OPTION_MULTILINE],
},
optionExamples: [
true,
[true, OPTION_MULTILINE],
],
type: "style",
typescriptOnly: false,
};
exports.Rule = Rule;
function walk(ctx) {
var sourceFile = ctx.sourceFile, multiline = ctx.options.multiline;
return ts.forEachChild(sourceFile, function cb(node) {
if (utils.isArrowFunction(node) && utils.isBlock(node.body)) {
var expr = getSimpleReturnExpression(node.body);
if (expr !== undefined && (multiline || utils.isSameLine(sourceFile, node.body.getStart(sourceFile), node.body.end))) {
var isObjectLiteral = expr.kind === ts.SyntaxKind.ObjectLiteralExpression;
ctx.addFailureAtNode(node.body, Rule.FAILURE_STRING(isObjectLiteral), createFix(node, node.body, expr, sourceFile.text));
}
}
return ts.forEachChild(node, cb);
});
}
function createFix(arrowFunction, body, expr, text) {
var statement = expr.parent;
var returnKeyword = Lint.childOfKind(statement, ts.SyntaxKind.ReturnKeyword);
var arrow = Lint.childOfKind(arrowFunction, ts.SyntaxKind.EqualsGreaterThanToken);
var openBrace = Lint.childOfKind(body, ts.SyntaxKind.OpenBraceToken);
var closeBrace = Lint.childOfKind(body, ts.SyntaxKind.CloseBraceToken);
var semicolon = Lint.childOfKind(statement, ts.SyntaxKind.SemicolonToken);
var anyComments = hasComments(arrow) || hasComments(openBrace) || hasComments(statement) || hasComments(returnKeyword) ||
hasComments(expr) || (semicolon !== undefined && hasComments(semicolon)) || hasComments(closeBrace);
return anyComments ? undefined : (expr.kind === ts.SyntaxKind.ObjectLiteralExpression ? [
Lint.Replacement.appendText(expr.getStart(), "("),
Lint.Replacement.appendText(expr.getEnd(), ")"),
] : []).concat([
// " {"
Lint.Replacement.deleteFromTo(arrow.end, openBrace.end),
// "return "
Lint.Replacement.deleteFromTo(statement.getStart(), expr.getStart()),
// " }" (may include semicolon)
Lint.Replacement.deleteFromTo(expr.end, closeBrace.end),
]);
function hasComments(node) {
return utils_1.hasCommentAfterPosition(text, node.getEnd());
}
}
/** Given `{ return x; }`, return `x`. */
function getSimpleReturnExpression(block) {
return block.statements.length === 1 && block.statements[0].kind === ts.SyntaxKind.ReturnStatement
? block.statements[0].expression
: undefined;
}
var _a;
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