Added allow and forbid options to no-namespace rule

docs/rules/no-namespace.md

@@ -13,6 +13,12 @@ Valid:
 import defaultExport from './foo'
 import { a, b }  from './bar'
 import defaultExport, { a, b }  from './foobar'
+
+// { allow: ['foo'] }
+import * as foo from 'foo';
+
+// { forbid: ['foo'] }
+import * as bar from 'bar';
 ```
 
 Invalid:
@@ -25,6 +31,22 @@ import * as foo from 'foo';
 import defaultExport, * as foo from 'foo';
 ```
 
+```js
+// { allow: ['foo'] }
+import * as bar from 'bar';
+
+// { forbid: ['foo'] }
+import * as foo from 'foo';
+```
+
+### Options
+
+This rule takes the following options:
+
+`allow`: an array of namespaces the rule allows
+
+`forbid`: an array of namespaces the rule forbids
+
 ## When Not To Use It
 
 If you want to use namespaces, you don't want to use this rule.

src/rules/no-namespace.js

@@ -17,7 +17,30 @@ module.exports = {
       url: docsUrl('no-namespace'),
     },
     fixable: 'code',
-    schema: [],
+    schema: [
+      {
+        oneOf: [
+          {
+            type: "object",
+            properties: {
+              allow: {
+                type: "array"
+              }
+            },
+            additionalProperties: false
+          },
+          {
+            type: "object",
+            properties: {
+              forbid: {
+                type: "array"
+              }
+            },
+            additionalProperties: false
+          }
+        ]
+      }
+    ]
   },
 
   create: function (context) {
@@ -31,6 +54,16 @@ module.exports = {
         const namespaceIdentifiers = namespaceReferences.map(reference => reference.identifier)
         const canFix = namespaceIdentifiers.length > 0 && !usesNamespaceAsObject(namespaceIdentifiers)
 
+        const config = context.options[0] || {
+          allow: [],
+        };
+
+        const [type, list] = Array.isArray(config.forbid)
+          ? ['forbid', config.forbid]
+          : ['allow', config.allow];
+
+        if (!shouldReport(type, list, namespaceVariable.name)) { return; }
+
         context.report({
           node,
           message: `Unexpected namespace import.`,
@@ -157,3 +190,17 @@ function generateLocalNames(names, nameConflicts, namespaceName) {
   })
   return localNames
 }
+
+/**
+ *
+ * @param {'forbid' | 'allow'} type
+ * @param {string[]} list
+ * @param {string} name
+ */
+function shouldReport(type, list, name) {
+  if (list.includes(name)) {
+    return type === 'forbid';
+  }
+
+  return type === 'allow';
+}

tests/src/rules/no-namespace.js

@@ -78,6 +78,8 @@ ruleTester.run('no-namespace', require('rules/no-namespace'), {
     { code: 'import { a, b } from \'./foo\';', parserOptions: { ecmaVersion: 2015, sourceType: 'module' } },
     { code: 'import bar from \'bar\';', parserOptions: { ecmaVersion: 2015, sourceType: 'module' } },
     { code: 'import bar from \'./bar\';', parserOptions: { ecmaVersion: 2015, sourceType: 'module' } },
+    { code: 'import * as bar from \'bar\';', parserOptions: { ecmaVersion: 2015, sourceType: 'module' }, options: [{ allow: ['bar']}] },
+    { code: 'import bar from \'bar\';', parserOptions: { ecmaVersion: 2015, sourceType: 'module' }, options: [{ forbid: ['bar']}] },
   ],
 
   invalid: [
@@ -108,6 +110,34 @@ ruleTester.run('no-namespace', require('rules/no-namespace'), {
         message: ERROR_MESSAGE,
       } ],
     }),
+    test({
+      code: 'import * as foo from \'./foo\';',
+      output: 'import * as foo from \'./foo\';',
+      options: [
+        {
+          forbid: ['foo']
+        }
+      ],
+      errors: [ {
+        line: 1,
+        column: 8,
+        message: ERROR_MESSAGE,
+      } ],
+    }),
+    test({
+      code: 'import * as foo from \'./foo\';',
+      output: 'import * as foo from \'./foo\';',
+      options: [
+        {
+          allow: ['bar']
+        }
+      ],
+      errors: [ {
+        line: 1,
+        column: 8,
+        message: ERROR_MESSAGE,
+      } ],
+    }),
     ...FIX_TESTS,
   ],
 })