Add no-interface-constructor rule

docs/_data/rules.json

@@ -715,6 +715,18 @@
     "typescriptOnly": true,
     "requiresTypeInfo": true
   },
+  {
+    "ruleName": "no-interface-constructor",
+    "description": "Warns on apparent attempts to define constructors for interfaces.",
+    "rationale": "`interface I { new(): I }` declares a type where for `x: I`, `new x()` is also of type `I`.",
+    "optionsDescription": "Not configurable.",
+    "options": null,
+    "optionExamples": [
+      "true"
+    ],
+    "type": "functionality",
+    "typescriptOnly": true
+  },
   {
     "ruleName": "no-internal-module",
     "description": "Disallows internal `module`",

docs/rules/no-interface-constructor/index.html

@@ -0,0 +1,14 @@
+---
+ruleName: no-interface-constructor
+description: Warns on apparent attempts to define constructors for interfaces.
+rationale: '`interface I { new(): I }` declares a type where for `x: I`, `new x()` is also of type `I`.'
+optionsDescription: Not configurable.
+options: null
+optionExamples:
+  - 'true'
+type: functionality
+typescriptOnly: true
+layout: rule
+title: 'Rule: no-interface-constructor'
+optionsJSON: 'null'
+---

src/rules/noInterfaceConstructorRule.ts

@@ -0,0 +1,60 @@
+/**
+ * @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.
+ */
+
+import * as ts from "typescript";
+
+import * as Lint from "../index";
+
+export class Rule extends Lint.Rules.AbstractRule {
+    /* tslint:disable:object-literal-sort-keys */
+    public static metadata: Lint.IRuleMetadata = {
+        ruleName: "no-interface-constructor",
+        description: "Warns on apparent attempts to define constructors for interfaces.",
+        rationale: "`interface I { new(): I }` declares a type where for `x: I`, `new x()` is also of type `I`.",
+        optionsDescription: "Not configurable.",
+        options: null,
+        optionExamples: ["true"],
+        type: "functionality",
+        typescriptOnly: true,
+    };
+    /* tslint:enable:object-literal-sort-keys */
+
+    public static FAILURE_STRING = "Interfaces cannot be constructed, only classes. Did you mean `declare class`?";
+
+    public apply(sourceFile: ts.SourceFile): Lint.RuleFailure[] {
+        return this.applyWithWalker(new Walker(sourceFile, this.getOptions()));
+    }
+}
+
+class Walker extends Lint.RuleWalker {
+    public visitConstructSignature(node: ts.ConstructSignatureDeclaration) {
+        const iface = node.parent as ts.InterfaceDeclaration;
+        if (iface.kind !== ts.SyntaxKind.InterfaceDeclaration) {
+            return;
+        }
+
+        const name = iface.name.text;
+        if (node.type.kind !== ts.SyntaxKind.TypeReference) {
+            return;
+        }
+
+        const typeName = (node.type as ts.TypeReferenceNode).typeName;
+        if (typeName.kind === ts.SyntaxKind.Identifier && (typeName as ts.Identifier).text === name) {
+            this.addFailureAtNode(node, Rule.FAILURE_STRING);
+        }
+    }
+}

test/rules/no-interface-constructor/test.ts.lint

@@ -0,0 +1,22 @@
+interface I {
+    new(): I;
+    ~~~~~~~~~ [0]
+}
+
+// Works for generic type.
+interface G {
+    new<T>(): G<T>;
+    ~~~~~~~~~~~~~~~ [0]
+}
+
+// OK if return type is not the interface.
+interface J {
+    new(): I;
+}
+
+// OK in type literal.
+type T = {
+    new(): T;
+}
+
+[0]: Interfaces cannot be constructed, only classes. Did you mean `declare class`?

test/rules/no-interface-constructor/tslint.json

@@ -0,0 +1,5 @@
+{
+  "rules": {
+    "no-interface-constructor": true
+  }
+}