feat(enum): Add allowLocal.

fixtures/no-const-enum/local/fixture.ts.lint

@@ -0,0 +1,7 @@
+export const enum Foo { FOO = "F" };
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     [no-const-enum]
+export enum Boo { BOO = "B" };
+enum Goo { GOO = "G" };
+const enum Moo { MOO = "M" };
+
+[no-const-enum]: const enum is forbidden

fixtures/no-const-enum/local/tsconfig.json

@@ -0,0 +1,8 @@
+{
+  "defaultSeverity": "error",
+  "jsRules": {},
+  "rules": {
+    "throw-error": { "severity": "error" }
+  },
+  "rulesDirectory": "../../../build/rules"
+}

fixtures/no-const-enum/local/tslint.json

@@ -0,0 +1,13 @@
+{
+  "defaultSeverity": "error",
+  "jsRules": {},
+  "rules": {
+    "no-const-enum": {
+      "options": [{
+        "allowLocal": true
+      }],
+      "severity": "error"
+    }
+  },
+  "rulesDirectory": "../../../build/rules"
+}

package.json

@@ -47,7 +47,7 @@
     "test": "yarn run lint && yarn run test:build && yarn run test:tslint",
     "test:build": "yarn run test:clean && tsc -p tsconfig.json",
     "test:clean": "rimraf build",
-    "test:debug": "tslint --test fixtures/no-unused-declaration/unused-imports/tslint.json",
+    "test:debug": "tslint --test fixtures/no-const-enum/local/tslint.json",
     "test:tslint": "tslint --test fixtures/**/tslint.json"
   },
   "version": "1.4.4"

source/rules/noConstEnumRule.ts

@@ -4,15 +4,23 @@
  */
 
 import * as Lint from "tslint";
+import * as tsutils from "tsutils";
 import * as ts from "typescript";
 import { tsquery } from "@phenomnomnominal/tsquery";
 
 export class Rule extends Lint.Rules.AbstractRule {
 
     public static metadata: Lint.IRuleMetadata = {
         description: "Disallows the use of const enums.",
-        options: null,
-        optionsDescription: "Not configurable.",
+        options: {
+            properties: {
+                allowLocal: { type: "boolean" }
+            },
+            type: "object"
+        },
+        optionsDescription: Lint.Utils.dedent`
+            An optional object with an optional \`allowLocal\` property - which defaults to \`false\`.
+            If \`allowLocal\` is \`true\`, only exported const enums are forbidden.`,
         requiresTypeInfo: false,
         ruleName: "no-const-enum",
         type: "functionality",
@@ -22,13 +30,22 @@ export class Rule extends Lint.Rules.AbstractRule {
     public static FAILURE_STRING = "const enum is forbidden";
 
     public apply(sourceFile: ts.SourceFile): Lint.RuleFailure[] {
+        const { ruleArguments } = this.getOptions();
+        const [options] = ruleArguments;
+        const allowLocal = options ? options.allowLocal : false;
         const failures: Lint.RuleFailure[] = [];
         const constKeywords = tsquery(
             sourceFile,
             "EnumDeclaration > ConstKeyword"
         );
         constKeywords.forEach((node: ts.Node) => {
             const enumDeclaration = node.parent as ts.EnumDeclaration;
+            if (allowLocal && !tsutils.hasModifier(
+                enumDeclaration.modifiers,
+                ts.SyntaxKind.ExportKeyword
+            )) {
+                return;
+            }
             failures.push(new Lint.RuleFailure(
                 sourceFile,
                 enumDeclaration.getStart(),