--- /dev/null
+"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 OPTION_CHECK_ELSE_IF = "check-else-if";
+var Rule = /** @class */ (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 (assigned) {
+ return "Use a conditional expression instead of assigning to '" + assigned + "' in multiple places.";
+ };
+ Rule.prototype.apply = function (sourceFile) {
+ return this.applyWithFunction(sourceFile, walk, {
+ checkElseIf: this.ruleArguments.indexOf(OPTION_CHECK_ELSE_IF) !== -1,
+ });
+ };
+ /* tslint:disable:object-literal-sort-keys */
+ Rule.metadata = {
+ ruleName: "prefer-conditional-expression",
+ description: Lint.Utils.dedent(templateObject_1 || (templateObject_1 = tslib_1.__makeTemplateObject(["\n Recommends to use a conditional expression instead of assigning to the same thing in each branch of an if statement."], ["\n Recommends to use a conditional expression instead of assigning to the same thing in each branch of an if statement."]))),
+ rationale: Lint.Utils.dedent(templateObject_2 || (templateObject_2 = tslib_1.__makeTemplateObject(["\n This reduces duplication and can eliminate an unnecessary variable declaration."], ["\n This reduces duplication and can eliminate an unnecessary variable declaration."]))),
+ optionsDescription: "If `" + OPTION_CHECK_ELSE_IF + "` is specified, the rule also checks nested if-else-if statements.",
+ options: {
+ type: "string",
+ enum: [OPTION_CHECK_ELSE_IF],
+ },
+ optionExamples: [true, [true, OPTION_CHECK_ELSE_IF]],
+ type: "functionality",
+ typescriptOnly: false,
+ };
+ return Rule;
+}(Lint.Rules.AbstractRule));
+exports.Rule = Rule;
+function walk(ctx) {
+ var sourceFile = ctx.sourceFile, checkElseIf = ctx.options.checkElseIf;
+ return ts.forEachChild(sourceFile, function cb(node) {
+ if (tsutils_1.isIfStatement(node)) {
+ var assigned = detectAssignment(node, sourceFile, checkElseIf);
+ if (assigned !== undefined) {
+ ctx.addFailureAtNode(node.getChildAt(0, sourceFile), Rule.FAILURE_STRING(assigned.getText(sourceFile)));
+ }
+ if (assigned !== undefined || !checkElseIf) {
+ // Be careful not to fail again for the "else if"
+ do {
+ ts.forEachChild(node.expression, cb);
+ ts.forEachChild(node.thenStatement, cb);
+ if (node.elseStatement === undefined) {
+ return;
+ }
+ node = node.elseStatement;
+ while (tsutils_1.isBlock(node) && node.statements.length === 1) {
+ node = node.statements[0];
+ }
+ } while (tsutils_1.isIfStatement(node));
+ }
+ }
+ return ts.forEachChild(node, cb);
+ });
+}
+/**
+ * @param inElse `undefined` when this is the top level if statement, `false` when inside the then branch, `true` when inside else
+ */
+function detectAssignment(statement, sourceFile, checkElseIf, inElse) {
+ if (tsutils_1.isIfStatement(statement)) {
+ if (inElse === false || (!checkElseIf && inElse) || statement.elseStatement === undefined) {
+ return undefined;
+ }
+ var then = detectAssignment(statement.thenStatement, sourceFile, checkElseIf, false);
+ if (then === undefined) {
+ return undefined;
+ }
+ var elze = detectAssignment(statement.elseStatement, sourceFile, checkElseIf, true);
+ return elze !== undefined && nodeEquals(then, elze, sourceFile) ? then : undefined;
+ }
+ else if (tsutils_1.isBlock(statement)) {
+ return statement.statements.length === 1
+ ? detectAssignment(statement.statements[0], sourceFile, checkElseIf, inElse)
+ : undefined;
+ }
+ else if (tsutils_1.isExpressionStatement(statement) && tsutils_1.isBinaryExpression(statement.expression)) {
+ var _a = statement.expression, kind = _a.operatorToken.kind, left = _a.left, right = _a.right;
+ return kind === ts.SyntaxKind.EqualsToken &&
+ tsutils_1.isSameLine(sourceFile, right.getStart(sourceFile), right.end)
+ ? left
+ : undefined;
+ }
+ else {
+ return undefined;
+ }
+}
+function nodeEquals(a, b, sourceFile) {
+ return a.getText(sourceFile) === b.getText(sourceFile);
+}
+var templateObject_1, templateObject_2;