github-pages-deploy-action/node_modules/tslint/lib/rules/noVoidExpressionRule.js
2019-11-19 07:48:29 -05:00

95 lines
5.2 KiB
JavaScript

"use strict";
/**
* @license
* Copyright 2018 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 OPTION_IGNORE_ARROW_FUNCTION_SHORTHAND = "ignore-arrow-function-shorthand";
var Rule = /** @class */ (function (_super) {
tslib_1.__extends(Rule, _super);
function Rule() {
return _super !== null && _super.apply(this, arguments) || this;
}
Rule.prototype.applyWithProgram = function (sourceFile, program) {
var ignoreArrowFunctionShorthand = this.ruleArguments.indexOf(OPTION_IGNORE_ARROW_FUNCTION_SHORTHAND) !== -1;
return this.applyWithFunction(sourceFile, walk, { ignoreArrowFunctionShorthand: ignoreArrowFunctionShorthand }, program.getTypeChecker());
};
/* tslint:disable:object-literal-sort-keys */
Rule.metadata = {
ruleName: "no-void-expression",
description: "Requires expressions of type `void` to appear in statement position.",
optionsDescription: Lint.Utils.dedent(templateObject_1 || (templateObject_1 = tslib_1.__makeTemplateObject(["\n If `", "` is provided, `() => returnsVoid()` will be allowed.\n Otherwise, it must be written as `() => { returnsVoid(); }`."], ["\n If \\`", "\\` is provided, \\`() => returnsVoid()\\` will be allowed.\n Otherwise, it must be written as \\`() => { returnsVoid(); }\\`."])), OPTION_IGNORE_ARROW_FUNCTION_SHORTHAND),
options: {
type: "array",
items: {
type: "string",
enum: [OPTION_IGNORE_ARROW_FUNCTION_SHORTHAND],
},
minLength: 0,
maxLength: 1,
},
rationale: Lint.Utils.dedent(templateObject_2 || (templateObject_2 = tslib_1.__makeTemplateObject(["\n It's misleading returning the results of an expression whose type is `void`.\n Attempting to do so is likely a symptom of expecting a different return type from a function.\n For example, the following code will log `undefined` but looks like it logs a value:\n\n ```\n const performWork = (): void => {\n workFirst();\n workSecond();\n };\n\n console.log(performWork());\n ```\n "], ["\n It's misleading returning the results of an expression whose type is \\`void\\`.\n Attempting to do so is likely a symptom of expecting a different return type from a function.\n For example, the following code will log \\`undefined\\` but looks like it logs a value:\n\n \\`\\`\\`\n const performWork = (): void => {\n workFirst();\n workSecond();\n };\n\n console.log(performWork());\n \\`\\`\\`\n "]))),
requiresTypeInfo: true,
type: "functionality",
typescriptOnly: false,
};
/* tslint:enable:object-literal-sort-keys */
Rule.FAILURE_STRING = "Expression has type `void`. Put it on its own line as a statement.";
return Rule;
}(Lint.Rules.TypedRule));
exports.Rule = Rule;
function walk(ctx, checker) {
var sourceFile = ctx.sourceFile, ignoreArrowFunctionShorthand = ctx.options.ignoreArrowFunctionShorthand;
return ts.forEachChild(sourceFile, function cb(node) {
if (isPossiblyVoidExpression(node) &&
!isParentAllowedVoid(node) &&
tsutils_1.isTypeFlagSet(checker.getTypeAtLocation(node), ts.TypeFlags.Void)) {
ctx.addFailureAtNode(node, Rule.FAILURE_STRING);
}
return ts.forEachChild(node, cb);
});
function isParentAllowedVoid(node) {
switch (node.parent.kind) {
case ts.SyntaxKind.ExpressionStatement:
return true;
case ts.SyntaxKind.ArrowFunction:
return ignoreArrowFunctionShorthand;
// Something like "x && console.log(x)".
case ts.SyntaxKind.BinaryExpression:
return isParentAllowedVoid(node.parent);
// Something like "!!cond ? console.log(true) : console.log(false)"
case ts.SyntaxKind.ConditionalExpression:
return true;
default:
return false;
}
}
}
function isPossiblyVoidExpression(node) {
switch (node.kind) {
case ts.SyntaxKind.AwaitExpression:
case ts.SyntaxKind.CallExpression:
case ts.SyntaxKind.TaggedTemplateExpression:
return true;
default:
return false;
}
}
var templateObject_1, templateObject_2;