test: make sure we fail on tapret commitment if no commitment was cre…

…ated

dbc/src/tapret/tx.rs

@@ -83,3 +83,40 @@ impl ConvolveCommit<mpc::Commitment, TapretProof, Lnpbp12> for Tx {
         Err(TapretError::NoTaprootOutput)
     }
 }
+
+#[cfg(test)]
+mod test {
+    use std::str::FromStr;
+
+    use amplify::hex::FromHex;
+    use amplify::Bytes32;
+    use bc::InternalPk;
+    use commit_verify::mpc::Commitment;
+    use secp256k1::{ffi, XOnlyPublicKey};
+
+    use super::*;
+    use crate::tapret::TapretPathProof;
+
+    #[test]
+    fn no_commitment() {
+        let tx = Tx::from_str(
+            "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"
+        ).unwrap();
+
+        let internal_pk: XOnlyPublicKey = unsafe {
+            ffi::XOnlyPublicKey::from_array_unchecked(<[u8; 64]>::from_hex(
+                "cb5271aa59fc637e29d034ec75363ca241fda5d3939684603b469b185be7e50f18ec6fd539e7dc1fd5fb4cf046d2cef5028a5ca0cdb09a252683e6a6eb2ad61d",
+            ).unwrap()).into()
+        };
+        let proof = TapretProof {
+            path_proof: TapretPathProof {
+                partner_node: None,
+                nonce: 0,
+            },
+            internal_pk: InternalPk::from(internal_pk),
+        };
+
+        let msg = Commitment::from(Bytes32::zero());
+        assert!(!ConvolveCommitProof::<_, Tx, _>::verify(&proof, &msg, &tx).unwrap())
+    }
+}