From 31971b5d2c69911b02ebf9322be9ddbe5a01fea6 Mon Sep 17 00:00:00 2001
From: Jaco <jacogr@gmail.com>
Date: Sun, 12 Jun 2022 09:36:41 +0200
Subject: [PATCH] Correct handling for storage Option<Option<Type>> (#4927)

* Correct handling for storage Option<Option<Type>>

* Adjust
---
 CHANGELOG.md                                 |  1 +
 packages/types-codec/src/base/Option.spec.ts | 18 +++++++++++++++
 packages/types-codec/src/base/Option.ts      | 23 +++++++++++++-------
 3 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 03998d2e26..6c20f37167 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ Contributed:
 
 Changes:
 
+- Ensure storage `Option<Option<Type>>` are correctly handled
 - Cater for named event fields (expose on event data as available)
 - Expose (partial) `runtimeVersion` on `api.at` interfaces
 - Add aliases for `DispatchError{U8, U8a}` (default to new `U8a` variant)
diff --git a/packages/types-codec/src/base/Option.spec.ts b/packages/types-codec/src/base/Option.spec.ts
index 7453d88bdd..9de96f5b4a 100644
--- a/packages/types-codec/src/base/Option.spec.ts
+++ b/packages/types-codec/src/base/Option.spec.ts
@@ -43,6 +43,24 @@ describe('Option', (): void => {
     });
   });
 
+  it('can decode a nested Option', (): void => {
+    expect(
+      new Option(
+        registry,
+        Option.with(Option.with(Text)),
+        new Option(
+          registry,
+          Option.with(Text),
+          new Option(
+            registry,
+            Text,
+            new Uint8Array([1, 3 << 2, 66, 67, 68])
+          )
+        )
+      ).toU8a()
+    ).toEqual(new Uint8Array([1, 1, 1, 3 << 2, 66, 67, 68]));
+  });
+
   it('can convert between different Some/None', (): void => {
     const def = '{ "foo":"Text", "zar":"Text" }';
     const none = new Option(registry, def, null);
diff --git a/packages/types-codec/src/base/Option.ts b/packages/types-codec/src/base/Option.ts
index dda66fb976..45f6da8b9e 100644
--- a/packages/types-codec/src/base/Option.ts
+++ b/packages/types-codec/src/base/Option.ts
@@ -29,16 +29,23 @@ class None extends Null {
 
 /** @internal */
 function decodeOption (registry: Registry, Type: CodecClass, value?: unknown): Codec {
-  // In the case of an option, unwrap the inner
-  if (value instanceof Option) {
-    value = value.value;
-  }
-
-  if (isNull(value) || isUndefined(value) || value === '0x' || value instanceof None) {
-    return new None(registry);
-  } else if (value instanceof Type) {
+  if (value instanceof Type) {
     // don't re-create, use as it (which also caters for derived types)
     return value;
+  } else if (value instanceof Option) {
+    if (value.value instanceof Type) {
+      // same instance, return it
+      return value.value;
+    } else if (value.isNone) {
+      // internal is None, we are also none
+      return new None(registry);
+    }
+
+    // convert the actual value into known
+    return new Type(registry, value.value);
+  } else if (isNull(value) || isUndefined(value) || value === '0x' || value instanceof None) {
+    // anyhting empty we pass as-is
+    return new None(registry);
   } else if (isU8a(value)) {
     // the isU8a check happens last in the if-tree - since the wrapped value
     // may be an instance of it, so Type and Option checks go in first