Initial commit (from f5274cbdce4ae7c9e4b937dcdf95ac70ae436d5f)

node_modules/tslint/lib/rules/unnecessaryElseRule.js

@@ -0,0 +1,135 @@
+"use strict";
+var _a, _b;
+Object.defineProperty(exports, "__esModule", { value: true });
+var tslib_1 = require("tslib");
+/**
+ * @license
+ * Copyright 2019 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.
+ */
+var utils = require("tsutils");
+var ts = require("typescript");
+var Lint = require("../index");
+var unnecessaryElse_examples_1 = require("./code-examples/unnecessaryElse.examples");
+var OPTION_ALLOW_ELSE_IF = "allow-else-if";
+var Rule = /** @class */ (function (_super) {
+    tslib_1.__extends(Rule, _super);
+    function Rule() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    /* tslint:disable:object-literal-sort-keys */
+    Rule.FAILURE_STRING = function (name) {
+        return "The preceding `if` block ends with a `" + name + "` statement. This `else` is unnecessary.";
+    };
+    Rule.prototype.apply = function (sourceFile) {
+        return this.applyWithFunction(sourceFile, walk, parseOptions(this.ruleArguments[0]));
+    };
+    /* tslint:disable:object-literal-sort-keys */
+    Rule.metadata = {
+        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."]))),
+        descriptionDetails: "",
+        optionExamples: [true, [true, (_a = {}, _a[OPTION_ALLOW_ELSE_IF] = true, _a)]],
+        options: {
+            type: "object",
+            properties: (_b = {},
+                _b[OPTION_ALLOW_ELSE_IF] = { type: "boolean" },
+                _b),
+        },
+        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),
+        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."]))),
+        ruleName: "unnecessary-else",
+        type: "style",
+        typescriptOnly: false,
+        codeExamples: unnecessaryElse_examples_1.codeExamples,
+    };
+    return Rule;
+}(Lint.Rules.AbstractRule));
+exports.Rule = Rule;
+function parseOptions(option) {
+    var _a;
+    return tslib_1.__assign((_a = {}, _a[OPTION_ALLOW_ELSE_IF] = false, _a), option);
+}
+function walk(ctx) {
+    var ifStatementStack = [];
+    function visitIfStatement(node) {
+        var jumpStatement = utils.isBlock(node.thenStatement)
+            ? getJumpStatement(getLastStatement(node.thenStatement))
+            : getJumpStatement(node.thenStatement);
+        ifStatementStack.push({ node: node, jumpStatement: jumpStatement });
+        if (jumpStatement !== undefined &&
+            node.elseStatement !== undefined &&
+            !recentStackParentMissingJumpStatement() &&
+            (!utils.isIfStatement(node.elseStatement) || !ctx.options[OPTION_ALLOW_ELSE_IF])) {
+            var elseKeyword = getPositionOfElseKeyword(node, ts.SyntaxKind.ElseKeyword);
+            ctx.addFailureAtNode(elseKeyword, Rule.FAILURE_STRING(jumpStatement));
+        }
+        ts.forEachChild(node, visitNode);
+        ifStatementStack.pop();
+    }
+    function recentStackParentMissingJumpStatement() {
+        if (ifStatementStack.length <= 1) {
+            return false;
+        }
+        for (var i = ifStatementStack.length - 2; i >= 0; i -= 1) {
+            var _a = ifStatementStack[i], jumpStatement = _a.jumpStatement, node = _a.node;
+            if (node.elseStatement !== ifStatementStack[i + 1].node) {
+                return false;
+            }
+            if (jumpStatement === undefined) {
+                return true;
+            }
+        }
+        return false;
+    }
+    function visitNode(node) {
+        if (utils.isIfStatement(node)) {
+            visitIfStatement(node);
+        }
+        else {
+            ts.forEachChild(node, visitNode);
+        }
+    }
+    ts.forEachChild(ctx.sourceFile, visitNode);
+}
+function getPositionOfElseKeyword(node, kind) {
+    return node.getChildren().filter(function (child) { return child.kind === kind; })[0];
+}
+function getJumpStatement(node) {
+    if (node === undefined) {
+        return undefined;
+    }
+    switch (node.kind) {
+        case ts.SyntaxKind.BreakStatement:
+            return "break";
+        case ts.SyntaxKind.ContinueStatement:
+            return "continue";
+        case ts.SyntaxKind.ThrowStatement:
+            return "throw";
+        case ts.SyntaxKind.ReturnStatement:
+            return "return";
+        default:
+            return undefined;
+    }
+}
+function getLastStatement(clause) {
+    var block = clause.statements[0];
+    var statements = clause.statements.length === 1 && utils.isBlock(block)
+        ? block.statements
+        : clause.statements;
+    return last(statements);
+}
+function last(arr) {
+    return arr[arr.length - 1];
+}
+var templateObject_1, templateObject_2, templateObject_3;