descriptor: add unit tests for constructing multipath keys

Author: apoelstra

src/descriptor/key.rs

@@ -1150,6 +1150,7 @@ mod test {
         MiniscriptKey, Wildcard,
     };
     use crate::prelude::*;
+    use crate::DefiniteDescriptorKey;
 
     #[test]
     fn parse_descriptor_key_errors() {
@@ -1497,4 +1498,23 @@ mod test {
         let public_key = DescriptorPublicKey::from_str(desc).unwrap();
         assert_tokens(&public_key, &[Token::String(desc)]);
     }
+
+    #[test]
+    fn definite_keys() {
+        // basic xpub
+        let desc = "xpub661MyMwAqRbcFtXgS5sYJABqqG9YLmC4Q1Rdap9gSE8NqtwybGhePY2gZ29ESFjqJoCu1Rupje8YtGqsefD265TMg7usUDFdp6W1EGMcet8"
+            .parse::<DescriptorPublicKey>()
+            .unwrap();
+        assert!(DefiniteDescriptorKey::new(desc).is_some());
+        // xpub with wildcard
+        let desc = "xpub661MyMwAqRbcFtXgS5sYJABqqG9YLmC4Q1Rdap9gSE8NqtwybGhePY2gZ29ESFjqJoCu1Rupje8YtGqsefD265TMg7usUDFdp6W1EGMcet8/*"
+            .parse::<DescriptorPublicKey>()
+            .unwrap();
+        assert!(DefiniteDescriptorKey::new(desc).is_none());
+        // multipath xpub
+        let desc = "xpub661MyMwAqRbcFtXgS5sYJABqqG9YLmC4Q1Rdap9gSE8NqtwybGhePY2gZ29ESFjqJoCu1Rupje8YtGqsefD265TMg7usUDFdp6W1EGMcet8/<0;1>"
+            .parse::<DescriptorPublicKey>()
+            .unwrap();
+        assert!(DefiniteDescriptorKey::new(desc).is_none());
+    }
 }