chore(NODE-4401): enable isolatedModules tsc compiler option (#507)

Author: thekorn

src/bson.ts

@@ -21,8 +21,8 @@ import { BSONRegExp } from './regexp';
 import { BSONSymbol } from './symbol';
 import { Timestamp } from './timestamp';
 import { UUID } from './uuid';
-export { BinaryExtended, BinaryExtendedLegacy, BinarySequence } from './binary';
-export { CodeExtended } from './code';
+export type { BinaryExtended, BinaryExtendedLegacy, BinarySequence } from './binary';
+export type { CodeExtended } from './code';
 export {
   BSON_BINARY_SUBTYPE_BYTE_ARRAY,
   BSON_BINARY_SUBTYPE_DEFAULT,
@@ -59,25 +59,22 @@ export {
   BSON_INT64_MAX,
   BSON_INT64_MIN
 } from './constants';
-export { DBRefLike } from './db_ref';
-export { Decimal128Extended } from './decimal128';
-export { DoubleExtended } from './double';
-export { EJSON, EJSONOptions } from './extended_json';
-export { Int32Extended } from './int_32';
-export { LongExtended } from './long';
-export { MaxKeyExtended } from './max_key';
-export { MinKeyExtended } from './min_key';
-export { ObjectIdExtended, ObjectIdLike } from './objectid';
-export { BSONRegExpExtended, BSONRegExpExtendedLegacy } from './regexp';
-export { BSONSymbolExtended } from './symbol';
-export {
-  LongWithoutOverrides,
-  LongWithoutOverridesClass,
-  TimestampExtended,
-  TimestampOverrides
-} from './timestamp';
-export { UUIDExtended } from './uuid';
-export { SerializeOptions, DeserializeOptions };
+export type { DBRefLike } from './db_ref';
+export type { Decimal128Extended } from './decimal128';
+export type { DoubleExtended } from './double';
+export type { EJSONOptions } from './extended_json';
+export { EJSON } from './extended_json';
+export type { Int32Extended } from './int_32';
+export type { LongExtended } from './long';
+export type { MaxKeyExtended } from './max_key';
+export type { MinKeyExtended } from './min_key';
+export type { ObjectIdExtended, ObjectIdLike } from './objectid';
+export type { BSONRegExpExtended, BSONRegExpExtendedLegacy } from './regexp';
+export type { BSONSymbolExtended } from './symbol';
+export type { LongWithoutOverrides, TimestampExtended, TimestampOverrides } from './timestamp';
+export { LongWithoutOverridesClass } from './timestamp';
+export type { UUIDExtended } from './uuid';
+export type { SerializeOptions, DeserializeOptions };
 export {
   Code,
   Map,

tsconfig.json

@@ -26,7 +26,8 @@
     // API-extractor makes use of the declarations, npm script should be cleaning these up
     "declaration": true,
     "declarationMap": true,
-    "types": []
+    "types": [],
+    "isolatedModules": true
   },
   "ts-node": {
     "transpileOnly": true,