From c8e38d6a5a6fbba233fb9cce7409b10c89aab593 Mon Sep 17 00:00:00 2001
From: "Tobin C. Harding" <me@tobin.cc>
Date: Thu, 23 Mar 2023 16:06:56 +1100
Subject: [PATCH] hashes: Implement JsonSchema for sha256t::Hash<T>

The derived implementation of `JsonSchema` recently stopped working as
described here:

https://github.com/rust-bitcoin/rust-bitcoin/pull/1696#issuecomment-1458670415

Implement the suggestion.
---
 hashes/src/sha256t.rs | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/hashes/src/sha256t.rs b/hashes/src/sha256t.rs
index 95c23e19..c45756c0 100644
--- a/hashes/src/sha256t.rs
+++ b/hashes/src/sha256t.rs
@@ -31,16 +31,17 @@ pub trait Tag {
 }
 
 /// Output of the SHA256t hash function.
-#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
 #[repr(transparent)]
-pub struct Hash<T: Tag>(
-    #[cfg_attr(
-        feature = "schemars",
-        schemars(schema_with = "crate::util::json_hex_string::len_32")
-    )]
-    [u8; 32],
-    #[cfg_attr(feature = "schemars", schemars(skip))] PhantomData<T>,
-);
+pub struct Hash<T: Tag>([u8; 32], PhantomData<T>);
+
+#[cfg(feature = "schemars")]
+impl<T: Tag> schemars::JsonSchema for Hash<T> {
+    fn schema_name() -> String { "Hash".to_owned() }
+
+    fn json_schema(gen: &mut schemars::gen::SchemaGenerator) -> schemars::schema::Schema {
+        crate::util::json_hex_string::len_32(gen)
+    }
+}
 
 impl<T: Tag> Hash<T> {
     fn internal_new(arr: [u8; 32]) -> Self { Hash(arr, Default::default()) }