Simplify transaction builder tests

Requires impl PartialEq for Transaction, which is implemented as a TxId
comparison (relying on the invariant that Transaction is immutable).

zcash_primitives/src/transaction/builder.rs

@@ -131,6 +131,7 @@ impl SaplingOutput {
 }
 
 /// Metadata about a transaction created by a [`Builder`].
+#[derive(Debug, PartialEq)]
 pub struct TransactionMetadata {
     spend_indices: Vec<usize>,
     output_indices: Vec<usize>,
@@ -554,22 +555,22 @@ mod tests {
         let to = extfvk.default_address().unwrap().1;
 
         let mut builder = Builder::new(0);
-        match builder.add_sapling_output(ovk, to, Amount::from_i64(-1).unwrap(), None) {
+        assert_eq!(
-            Err(e) => assert_eq!(e, Error::InvalidAmount),
+            builder.add_sapling_output(ovk, to, Amount::from_i64(-1).unwrap(), None),
-            Ok(_) => panic!("Should have failed"),
+            Err(Error::InvalidAmount)
-        }
+        );
     }
 
     #[test]
     fn fails_on_negative_transparent_output() {
         let mut builder = Builder::new(0);
-        match builder.add_transparent_output(
+        assert_eq!(
-            &TransparentAddress::PublicKey([0; 20]),
+            builder.add_transparent_output(
-            Amount::from_i64(-1).unwrap(),
+                &TransparentAddress::PublicKey([0; 20]),
-        ) {
+                Amount::from_i64(-1).unwrap(),
-            Err(e) => assert_eq!(e, Error::InvalidAmount),
+            ),
-            Ok(_) => panic!("Should have failed"),
+            Err(Error::InvalidAmount)
-        }
+        );
     }
 
     #[test]
@@ -583,13 +584,10 @@ mod tests {
         // 0.0001 t-ZEC fee
         {
             let builder = Builder::new(0);
-            match builder.build(1, MockTxProver) {
+            assert_eq!(
-                Err(e) => assert_eq!(
+                builder.build(1, MockTxProver),
-                    e,
+                Err(Error::ChangeIsNegative(Amount::from_i64(-10000).unwrap()))
-                    Error::ChangeIsNegative(Amount::from_i64(-10000).unwrap())
+            );
-                ),
-                Ok(_) => panic!("Should have failed"),
-            }
         }
 
         let extfvk = ExtendedFullViewingKey::from(&extsk);
@@ -608,13 +606,10 @@ mod tests {
                     None,
                 )
                 .unwrap();
-            match builder.build(1, MockTxProver) {
+            assert_eq!(
-                Err(e) => assert_eq!(
+                builder.build(1, MockTxProver),
-                    e,
+                Err(Error::ChangeIsNegative(Amount::from_i64(-60000).unwrap()))
-                    Error::ChangeIsNegative(Amount::from_i64(-60000).unwrap())
+            );
-                ),
-                Ok(_) => panic!("Should have failed"),
-            }
         }
 
         // Fail if there is only a transparent output
@@ -627,13 +622,10 @@ mod tests {
                     Amount::from_u64(50000).unwrap(),
                 )
                 .unwrap();
-            match builder.build(1, MockTxProver) {
+            assert_eq!(
-                Err(e) => assert_eq!(
+                builder.build(1, MockTxProver),
-                    e,
+                Err(Error::ChangeIsNegative(Amount::from_i64(-60000).unwrap()))
-                    Error::ChangeIsNegative(Amount::from_i64(-60000).unwrap())
+            );
-                ),
-                Ok(_) => panic!("Should have failed"),
-            }
         }
 
         let note1 = to
@@ -670,10 +662,10 @@ mod tests {
                     Amount::from_u64(20000).unwrap(),
                 )
                 .unwrap();
-            match builder.build(1, MockTxProver) {
+            assert_eq!(
-                Err(e) => assert_eq!(e, Error::ChangeIsNegative(Amount::from_i64(-1).unwrap())),
+                builder.build(1, MockTxProver),
-                Ok(_) => panic!("Should have failed"),
+                Err(Error::ChangeIsNegative(Amount::from_i64(-1).unwrap()))
-            }
+            );
         }
 
         let note2 = to.create_note(1, Fs::random(&mut rng), &JUBJUB).unwrap();
@@ -704,10 +696,7 @@ mod tests {
                     Amount::from_u64(20000).unwrap(),
                 )
                 .unwrap();
-            match builder.build(1, MockTxProver) {
+            assert_eq!(builder.build(1, MockTxProver), Err(Error::BindingSig))
-                Err(e) => assert_eq!(e, Error::BindingSig),
-                Ok(_) => panic!("Should have failed"),
-            }
         }
     }
 }

zcash_primitives/src/transaction/mod.rs

@@ -50,6 +50,12 @@ impl Deref for Transaction {
     }
 }
 
+impl PartialEq for Transaction {
+    fn eq(&self, other: &Transaction) -> bool {
+        self.txid == other.txid
+    }
+}
+
 pub struct TransactionData {
     pub overwintered: bool,
     pub version: u32,