Add 'no-const-enum' rule

docs/no-const-enum.md

@@ -0,0 +1,16 @@
+# no-const-enum
+
+Avoid using `const enum`s. These can't be used by JavaScript users or by TypeScript users with [`--isolatedModules`](https://www.typescriptlang.org/docs/handbook/compiler-options.html) enabled.
+
+**Bad**:
+
+```ts
+const enum Bit { Off, On }
+export function f(b: Bit): void;
+```
+
+**Good**:
+
+```ts
+export function f(b: 0 | 1): void;
+```

dtslint.json

@@ -6,6 +6,7 @@
 		"expect": true,
 		"export-just-namespace": true,
 		"no-bad-reference": true,
+		"no-const-enum": true,
 		"no-dead-reference": true,
 		"no-padding": true,
 		"no-redundant-undefined": true,

src/rules/noConstEnumRule.ts

@@ -0,0 +1,32 @@
+import * as Lint from "tslint";
+import * as ts from "typescript";
+
+import { failure } from "../util";
+
+export class Rule extends Lint.Rules.AbstractRule {
+	static metadata: Lint.IRuleMetadata = {
+		ruleName: "no-const-enum",
+		description: "Forbid `const enum`",
+		optionsDescription: "Not configurable.",
+		options: null,
+		type: "functionality",
+		typescriptOnly: true,
+	};
+
+	static FAILURE_STRING = failure(
+		Rule.metadata.ruleName,
+		"Use of `const enum`s is forbidden.");
+
+	apply(sourceFile: ts.SourceFile): Lint.RuleFailure[] {
+		return this.applyWithFunction(sourceFile, walk);
+	}
+}
+
+function walk(ctx: Lint.WalkContext<void>): void {
+	ctx.sourceFile.forEachChild(function recur(node) {
+		if (ts.isEnumDeclaration(node) && node.modifiers && node.modifiers.some(m => m.kind === ts.SyntaxKind.ConstKeyword)) {
+			ctx.addFailureAtNode(node.name, Rule.FAILURE_STRING);
+		}
+		node.forEachChild(recur);
+	});
+}

test/no-const-enum/test.ts.lint

@@ -0,0 +1,7 @@
+const enum E {
+           ~ [0]
+}
+
+enum F {}
+
+[0]: Use of `const enum`s is forbidden. See: https://github.com/Microsoft/dtslint/blob/master/docs/no-const-enum.md

test/no-const-enum/tslint.json

@@ -0,0 +1,6 @@
+{
+  "rulesDirectory": ["../../bin/rules"],
+  "rules": {
+    "no-const-enum": true
+  }
+}