test: ensure our enums are types and values (#3146)

test/types/enum.test-d.ts

@@ -0,0 +1,47 @@
+/* eslint-disable @typescript-eslint/no-unused-vars */
+import { expectAssignable, expectType } from 'tsd';
+
+import {
+  AuthMechanism,
+  AutoEncryptionLoggerLevel,
+  BatchType,
+  BSONType,
+  Compressor,
+  CURSOR_FLAGS,
+  CursorFlag,
+  ExplainVerbosity,
+  GSSAPICanonicalizationValue,
+  LoggerLevel,
+  ProfilingLevel,
+  ReadConcernLevel,
+  ReadPreferenceMode,
+  ReturnDocument,
+  ServerApiVersion,
+  ServerType,
+  TopologyType
+} from '../../src/index';
+
+const num: number = Math.random();
+
+// In our index.ts we clump CURSOR_FLAGS with the enums but its an array
+expectType<CursorFlag>(CURSOR_FLAGS[num]);
+
+// Explain is kept as type string so we can automatically allow any new level to be passed through
+expectAssignable<string>(Object.values(ExplainVerbosity)[num]);
+
+// Note both the Enum name and a property on the enum are the same type
+// Object.values(x)[num] gets a union of the all the value types
+expectType<AuthMechanism>(Object.values(AuthMechanism)[num]);
+expectType<AutoEncryptionLoggerLevel>(Object.values(AutoEncryptionLoggerLevel)[num]);
+expectType<BatchType>(Object.values(BatchType)[num]);
+expectType<BSONType>(Object.values(BSONType)[num]);
+expectType<Compressor>(Object.values(Compressor)[num]);
+expectType<GSSAPICanonicalizationValue>(Object.values(GSSAPICanonicalizationValue)[num]);
+expectType<LoggerLevel>(Object.values(LoggerLevel)[num]);
+expectType<ProfilingLevel>(Object.values(ProfilingLevel)[num]);
+expectType<ReadConcernLevel>(Object.values(ReadConcernLevel)[num]);
+expectType<ReadPreferenceMode>(Object.values(ReadPreferenceMode)[num]);
+expectType<ReturnDocument>(Object.values(ReturnDocument)[num]);
+expectType<ServerApiVersion>(Object.values(ServerApiVersion)[num]);
+expectType<ServerType>(Object.values(ServerType)[num]);
+expectType<TopologyType>(Object.values(TopologyType)[num]);