Deprecate `transaction::components::amount::DEFAULT_FEE` and

`zcash_primitives::transaction::fees::fixed::FeeRule::standard()`.

Signed-off-by: Daira Emma Hopwood <daira@jacaranda.org>

zcash_client_backend/src/data_api/wallet.rs

@@ -184,7 +184,9 @@ where
 /// [`sapling::TxProver`]: zcash_primitives::sapling::prover::TxProver
 #[allow(clippy::too_many_arguments)]
 #[allow(clippy::type_complexity)]
-#[deprecated(note = "Use `spend` instead.")]
+#[deprecated(
+    note = "Use `spend` instead. Note that this uses a fixed fee of 10000 zatoshis, which is not compliant with ZIP 317."
+)]
 pub fn create_spend_to_address<DbT, ParamsT>(
     wallet_db: &mut DbT,
     params: &ParamsT,
@@ -221,7 +223,9 @@ where
         "It should not be possible for this to violate ZIP 321 request construction invariants.",
     );
 
-    let change_strategy = fees::fixed::SingleOutputChangeStrategy::new(fixed::FeeRule::standard());
+    #[allow(deprecated)]
+    let fee_rule = fixed::FeeRule::standard();
+    let change_strategy = fees::fixed::SingleOutputChangeStrategy::new(fee_rule);
     spend(
         wallet_db,
         params,

zcash_primitives/CHANGELOG.md

@@ -82,6 +82,14 @@ and this library adheres to Rust's notion of
   (10000 zatoshis rather than 1000 zatoshis) as the fixed fee. To be compliant with
   ZIP 317, use `transaction::fees::zip317::FeeRule::standard()` instead.
 
+### Deprecated
+- `transaction::components::amount::DEFAULT_FEE` has been deprecated. Depending on
+  context, you may want to use `transaction::fees::zip317::MINIMUM_FEE`, or calculate
+  the ZIP 317 conventional fee using `transaction::fees::zip317::FeeRule` instead.
+- `transaction::fees::fixed::FeeRule::standard()` has been deprecated.
+  Use either `transaction::fees::zip317::FeeRule::standard()` or
+  `transaction::fees::fixed::FeeRule::non_standard`.
+
 ## [0.11.0] - 2023-04-15
 ### Added
 - `zcash_primitives::zip32::fingerprint` module, containing types for deriving

zcash_primitives/src/transaction/builder.rs

@@ -533,6 +533,7 @@ mod testing {
         }
 
         pub fn mock_build(self) -> Result<(Transaction, SaplingMetadata), Error<Infallible>> {
+            #[allow(deprecated)]
             self.build(&MockTxProver, &fixed::FeeRule::standard())
         }
     }

zcash_primitives/src/transaction/components/amount.rs

@@ -8,6 +8,12 @@ use orchard::value as orchard;
 pub const COIN: i64 = 1_0000_0000;
 pub const MAX_MONEY: i64 = 21_000_000 * COIN;
 
+#[deprecated(
+    since = "0.12.0",
+    note = "To calculate the ZIP 317 fee, use `transaction::fees::zip317::FeeRule`.
+For a constant representing the minimum ZIP 317 fee, use `transaction::fees::zip317::MINIMUM_FEE`.
+For the constant amount 1000 zatoshis, use `Amount::const_from_i64(1000)`."
+)]
 pub const DEFAULT_FEE: Amount = Amount(1000);
 
 /// A type-safe representation of some quantity of Zcash.

zcash_primitives/src/transaction/fees/fixed.rs

@@ -24,10 +24,15 @@ impl FeeRule {
     /// i.e. 10000 zatoshis.
     ///
     /// Note that using a fixed fee is not compliant with [ZIP 317]; consider
-    /// using [`zcash_primitives::transaction::fees::zip317::FeeRule`] instead.
+    /// using [`zcash_primitives::transaction::fees::zip317::FeeRule::standard()`]
+    /// instead.
     ///
-    /// [`zcash_primitives::transaction::fees::zip317::FeeRule`]: crate::transaction::fees::zip317::FeeRule
+    /// [`zcash_primitives::transaction::fees::zip317::FeeRule::standard()`]: crate::transaction::fees::zip317::FeeRule::standard
     /// [ZIP 317]: https://zips.z.cash/zip-0317
+    #[deprecated(
+        since = "0.12.0",
+        note = "To calculate the ZIP 317 fee, use `transaction::fees::zip317::FeeRule::standard()`. For a fixed fee, use the `non_standard` constructor."
+    )]
     pub fn standard() -> Self {
         Self {
             fixed_fee: zip317::MINIMUM_FEE,