Add tests for enums

tests/enums.js

@@ -0,0 +1,39 @@
+type Type = {
+    a: 'one' | 'two',
+};
+
+interface Interface {
+    a: 'one' | 'two';
+}
+
+class Class {
+    a: 'one' | 'two';
+}
+
+// ###
+({
+    Type: {
+        type: 'record',
+        name: 'Type',
+        fields: [{
+            name: 'a',
+            type: {type: 'enum', symbols: ['one', 'two']},
+        }],
+    },
+    Interface: {
+        type: 'record',
+        name: 'Interface',
+        fields: [{
+            name: 'a',
+            type: {type: 'enum', symbols: ['one', 'two']},
+        }],
+    },
+    Class: {
+        type: 'record',
+        name: 'Class',
+        fields: [{
+            name: 'a',
+            type: {type: 'enum', symbols: ['one', 'two']},
+        }],
+    },
+});