1 files changed, 96 insertions, 0 deletions
diff --git a/node_modules/tslint/lib/rules/preferConditionalExpressionRule.js b/node_modules/tslint/lib/rules/preferConditionalExpressionRule.js
new file mode 100644
index 000000000..7be4cbcbe
--- /dev/null
+++ b/node_modules/tslint/lib/rules/preferConditionalExpressionRule.js
@@ -0,0 +1,96 @@
+"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 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 (assigned) {
+        return "Use a conditional expression instead of assigning to '" + assigned + "' in multiple places.";
+    };
+    Rule.prototype.apply = function (sourceFile) {
+        return this.applyWithFunction(sourceFile, walk);
+    };
+    return Rule;
+}(Lint.Rules.AbstractRule));
+/* tslint:disable:object-literal-sort-keys */
+Rule.metadata = {
+    ruleName: "prefer-conditional-expression",
+    description: (_a = ["\n            Recommends to use a conditional expression instead of assigning to the same thing in each branch of an if statement."], _a.raw = ["\n            Recommends to use a conditional expression instead of assigning to the same thing in each branch of an if statement."], Lint.Utils.dedent(_a)),
+    rationale: (_b = ["\n            This reduces duplication and can eliminate an unnecessary variable declaration."], _b.raw = ["\n            This reduces duplication and can eliminate an unnecessary variable declaration."], Lint.Utils.dedent(_b)),
+    optionsDescription: "Not configurable.",
+    options: null,
+    optionExamples: [true],
+    type: "functionality",
+    typescriptOnly: false,
+};
+exports.Rule = Rule;
+function walk(ctx) {
+    var sourceFile = ctx.sourceFile;
+    return ts.forEachChild(sourceFile, function cb(node) {
+        if (tsutils_1.isIfStatement(node)) {
+            var assigned = detect(node, sourceFile);
+            if (assigned !== undefined) {
+                ctx.addFailureAtNode(Lint.childOfKind(node, ts.SyntaxKind.IfKeyword), Rule.FAILURE_STRING(assigned.getText(sourceFile)));
+                // Be careful not to fail again for the "else if"
+                ts.forEachChild(node.expression, cb);
+                ts.forEachChild(node.thenStatement, cb);
+                if (node.elseStatement !== undefined) {
+                    ts.forEachChild(node.elseStatement, cb);
+                }
+                return;
+            }
+        }
+        return ts.forEachChild(node, cb);
+    });
+}
+function detect(_a, sourceFile) {
+    var thenStatement = _a.thenStatement, elseStatement = _a.elseStatement;
+    if (elseStatement === undefined) {
+        return undefined;
+    }
+    var elze = tsutils_1.isIfStatement(elseStatement) ? detect(elseStatement, sourceFile) : getAssigned(elseStatement, sourceFile);
+    if (elze === undefined) {
+        return undefined;
+    }
+    var then = getAssigned(thenStatement, sourceFile);
+    return then !== undefined && nodeEquals(elze, then, sourceFile) ? then : undefined;
+}
+/** Returns the left side of an assignment. */
+function getAssigned(node, sourceFile) {
+    if (tsutils_1.isBlock(node)) {
+        return node.statements.length === 1 ? getAssigned(node.statements[0], sourceFile) : undefined;
+    }
+    else if (tsutils_1.isExpressionStatement(node) && tsutils_1.isBinaryExpression(node.expression)) {
+        var _a = node.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 _a, _b;