zcash_protocol: Add constructors to LocalNetwork

components/zcash_protocol/CHANGELOG.md

@@ -10,6 +10,8 @@ and this library adheres to Rust's notion of
 ### Added
 - `zcash_protocol::memo`:
   - `impl TryFrom<&MemoBytes> for Memo`
+- `zcash_protocol::local_consensus`:
+  - `new`, `all_upgrades_active` and `canopy_active` constructors to `LocalNetwork`
 
 ### Removed
 - `unstable-nu6` and `zfuture` feature flags (use `--cfg zcash_unstable=\"nu6\"`

components/zcash_protocol/src/local_consensus.rs

@@ -43,6 +43,54 @@ pub struct LocalNetwork {
     pub z_future: Option<BlockHeight>,
 }
 
+impl LocalNetwork {
+    /// Construct a new `LocalNetwork` where all network upgrade activation heights are specified.
+    ///
+    /// Sequential network upgrades may share the same activation height but this constructor will
+    /// panic if the order in which network upgrades activate is changed.
+    pub fn new(
+        overwinter: u64,
+        sapling: u64,
+        blossom: u64,
+        heartwood: u64,
+        canopy: u64,
+        nu5: u64,
+    ) -> Self {
+        assert!(
+            overwinter <= sapling
+                && sapling <= blossom
+                && blossom <= heartwood
+                && heartwood <= canopy
+                && canopy <= nu5,
+            "Network upgrade activation heights must be in ascending order"
+        );
+
+        LocalNetwork {
+            overwinter: Some(BlockHeight::from_u32(overwinter as u32)),
+            sapling: Some(BlockHeight::from_u32(sapling as u32)),
+            blossom: Some(BlockHeight::from_u32(blossom as u32)),
+            heartwood: Some(BlockHeight::from_u32(heartwood as u32)),
+            canopy: Some(BlockHeight::from_u32(canopy as u32)),
+            nu5: Some(BlockHeight::from_u32(nu5 as u32)),
+            #[cfg(zcash_unstable = "nu6")]
+            nu6: None,
+            #[cfg(zcash_unstable = "zfuture")]
+            z_future: None,
+        }
+    }
+
+    /// Construct a new `LocalNetwork` with all network upgrades initially active.
+    pub fn all_upgrades_active() -> Self {
+        Self::new(1, 1, 1, 1, 1, 1)
+    }
+
+    /// Construct a new `LocalNetwork` with all network upgrades up to and including canopy
+    /// initally active.
+    pub fn canopy_active(nu5_activation_height: u64) -> Self {
+        Self::new(1, 1, 1, 1, 1, nu5_activation_height)
+    }
+}
+
 /// Parameters implementation for `LocalNetwork`
 impl Parameters for LocalNetwork {
     fn network_type(&self) -> NetworkType {