137 lines
6.1 KiB
JavaScript
137 lines
6.1 KiB
JavaScript
"use strict";
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var _a, _b;
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.Rule = void 0;
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var tslib_1 = require("tslib");
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/**
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* @license
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* Copyright 2019 Palantir Technologies, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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var utils = require("tsutils");
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var ts = require("typescript");
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var Lint = require("../index");
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var unnecessaryElse_examples_1 = require("./code-examples/unnecessaryElse.examples");
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var OPTION_ALLOW_ELSE_IF = "allow-else-if";
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var Rule = /** @class */ (function (_super) {
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tslib_1.__extends(Rule, _super);
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function Rule() {
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return _super !== null && _super.apply(this, arguments) || this;
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}
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/* tslint:disable:object-literal-sort-keys */
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Rule.FAILURE_STRING = function (name) {
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return "The preceding `if` block ends with a `" + name + "` statement. This `else` is unnecessary.";
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};
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Rule.prototype.apply = function (sourceFile) {
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return this.applyWithFunction(sourceFile, walk, parseOptions(this.ruleArguments[0]));
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};
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/* tslint:disable:object-literal-sort-keys */
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Rule.metadata = {
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description: Lint.Utils.dedent(templateObject_1 || (templateObject_1 = tslib_1.__makeTemplateObject(["\n Disallows `else` blocks following `if` blocks ending with a `break`, `continue`, `return`, or `throw` statement."], ["\n Disallows \\`else\\` blocks following \\`if\\` blocks ending with a \\`break\\`, \\`continue\\`, \\`return\\`, or \\`throw\\` statement."]))),
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descriptionDetails: "",
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optionExamples: [true, [true, (_a = {}, _a[OPTION_ALLOW_ELSE_IF] = true, _a)]],
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options: {
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type: "object",
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properties: (_b = {},
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_b[OPTION_ALLOW_ELSE_IF] = { type: "boolean" },
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_b),
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},
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optionsDescription: Lint.Utils.dedent(templateObject_2 || (templateObject_2 = tslib_1.__makeTemplateObject(["\n You can optionally specify the option `\"", "\"` to allow \"else if\" statements.\n "], ["\n You can optionally specify the option \\`\"", "\"\\` to allow \"else if\" statements.\n "])), OPTION_ALLOW_ELSE_IF),
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rationale: Lint.Utils.dedent(templateObject_3 || (templateObject_3 = tslib_1.__makeTemplateObject(["\n When an `if` block is guaranteed to exit control flow when entered,\n it is unnecessary to add an `else` statement.\n The contents that would be in the `else` block can be placed after the end of the `if` block."], ["\n When an \\`if\\` block is guaranteed to exit control flow when entered,\n it is unnecessary to add an \\`else\\` statement.\n The contents that would be in the \\`else\\` block can be placed after the end of the \\`if\\` block."]))),
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ruleName: "unnecessary-else",
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type: "style",
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typescriptOnly: false,
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codeExamples: unnecessaryElse_examples_1.codeExamples,
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};
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return Rule;
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}(Lint.Rules.AbstractRule));
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exports.Rule = Rule;
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function parseOptions(option) {
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var _a;
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return tslib_1.__assign((_a = {}, _a[OPTION_ALLOW_ELSE_IF] = false, _a), option);
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}
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function walk(ctx) {
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var ifStatementStack = [];
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function visitIfStatement(node) {
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var jumpStatement = utils.isBlock(node.thenStatement)
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? getJumpStatement(getLastStatement(node.thenStatement))
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: getJumpStatement(node.thenStatement);
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ifStatementStack.push({ node: node, jumpStatement: jumpStatement });
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if (jumpStatement !== undefined &&
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node.elseStatement !== undefined &&
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!recentStackParentMissingJumpStatement() &&
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(!utils.isIfStatement(node.elseStatement) || !ctx.options[OPTION_ALLOW_ELSE_IF])) {
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var elseKeyword = getPositionOfElseKeyword(node, ts.SyntaxKind.ElseKeyword);
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ctx.addFailureAtNode(elseKeyword, Rule.FAILURE_STRING(jumpStatement));
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}
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ts.forEachChild(node, visitNode);
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ifStatementStack.pop();
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}
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function recentStackParentMissingJumpStatement() {
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if (ifStatementStack.length <= 1) {
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return false;
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}
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for (var i = ifStatementStack.length - 2; i >= 0; i -= 1) {
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var _a = ifStatementStack[i], jumpStatement = _a.jumpStatement, node = _a.node;
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if (node.elseStatement !== ifStatementStack[i + 1].node) {
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return false;
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}
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if (jumpStatement === undefined) {
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return true;
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}
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}
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return false;
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}
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function visitNode(node) {
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if (utils.isIfStatement(node)) {
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visitIfStatement(node);
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}
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else {
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ts.forEachChild(node, visitNode);
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}
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}
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ts.forEachChild(ctx.sourceFile, visitNode);
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}
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function getPositionOfElseKeyword(node, kind) {
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return node.getChildren().filter(function (child) { return child.kind === kind; })[0];
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}
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function getJumpStatement(node) {
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if (node === undefined) {
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return undefined;
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}
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switch (node.kind) {
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case ts.SyntaxKind.BreakStatement:
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return "break";
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case ts.SyntaxKind.ContinueStatement:
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return "continue";
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case ts.SyntaxKind.ThrowStatement:
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return "throw";
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case ts.SyntaxKind.ReturnStatement:
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return "return";
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default:
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return undefined;
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}
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}
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function getLastStatement(clause) {
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var block = clause.statements[0];
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var statements = clause.statements.length === 1 && utils.isBlock(block)
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? block.statements
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: clause.statements;
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return last(statements);
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}
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function last(arr) {
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return arr[arr.length - 1];
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}
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var templateObject_1, templateObject_2, templateObject_3;
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