From 9513f9832375c3962e64150d422a2acf82b34104 Mon Sep 17 00:00:00 2001
From: Alex Malkevich <alex.malkevich@mcmakler.de>
Date: Thu, 7 Feb 2019 18:40:54 +0100
Subject: [PATCH] fix(generator): safely access reserved exports from `io-ts`

Because of the bug in rollup https://github.com/rollup/rollup/issues/2680

re #5
---
 projects/gen-io-ts/src/lib/generator.ts | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/projects/gen-io-ts/src/lib/generator.ts b/projects/gen-io-ts/src/lib/generator.ts
index 245e7ac..c4088a5 100644
--- a/projects/gen-io-ts/src/lib/generator.ts
+++ b/projects/gen-io-ts/src/lib/generator.ts
@@ -4,6 +4,16 @@ import { ResolvedTypeMetadata, resolveMetadataOf } from './metadata';
 import { Primitive, Type } from './types';
 import { isBuiltinType, isObject, isPrimitive } from './util';
 
+/**
+ * Required to safely access from `io-ts` reserved exports like `undefined`
+ * because of the bug in rollup
+ * @see https://github.com/rollup/rollup/issues/2680
+ * @internal
+ */
+function getIoTs<K extends keyof typeof t>(prop: K) {
+  return t[prop];
+}
+
 /**
  * Generate `io-ts` codec for `type`
  *
@@ -26,7 +36,7 @@ function genTypeFor(obj: any, name?: string): t.Type<any> {
   }
 
   if (metadata && !metadata.isRequired) {
-    codec = t.union([codec, t.null, t.undefined]);
+    codec = t.union([codec, getIoTs('null'), getIoTs('undefined')]);
   }
 
   return codec;