From f15b33bca778be41c33af24fb77a9110145ddfcb Mon Sep 17 00:00:00 2001
From: dharjeezy <dharjeezy@gmail.com>
Date: Thu, 8 Dec 2022 15:09:17 +0100
Subject: [PATCH] [pallet-assets] add asset_exists(id: AssetId) function
 (#12782)

* check if an asset exists via loose coupling

* Update frame/support/src/traits/tokens/fungibles.rs

Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>

Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Co-authored-by: parity-processbot <>
---
 frame/assets/src/impl_fungibles.rs           | 4 ++++
 frame/support/src/traits/tokens/fungibles.rs | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/frame/assets/src/impl_fungibles.rs b/frame/assets/src/impl_fungibles.rs
index 6e0a9ac08ebb1..b10b8c6b10755 100644
--- a/frame/assets/src/impl_fungibles.rs
+++ b/frame/assets/src/impl_fungibles.rs
@@ -59,6 +59,10 @@ impl<T: Config<I>, I: 'static> fungibles::Inspect<<T as SystemConfig>::AccountId
 	) -> WithdrawConsequence<Self::Balance> {
 		Pallet::<T, I>::can_decrease(asset, who, amount, false)
 	}
+
+	fn asset_exists(asset: Self::AssetId) -> bool {
+		Asset::<T, I>::contains_key(asset)
+	}
 }
 
 impl<T: Config<I>, I: 'static> fungibles::InspectMetadata<<T as SystemConfig>::AccountId>
diff --git a/frame/support/src/traits/tokens/fungibles.rs b/frame/support/src/traits/tokens/fungibles.rs
index 6cc6d70de15a7..045ecd05134c2 100644
--- a/frame/support/src/traits/tokens/fungibles.rs
+++ b/frame/support/src/traits/tokens/fungibles.rs
@@ -83,6 +83,9 @@ pub trait Inspect<AccountId> {
 		who: &AccountId,
 		amount: Self::Balance,
 	) -> WithdrawConsequence<Self::Balance>;
+
+	/// Returns `true` if an `asset` exists.
+	fn asset_exists(asset: Self::AssetId) -> bool;
 }
 
 /// Trait for reading metadata from a fungible asset.