zcash_client_sqlite: Use a seeded RNG in `TestState`

This makes individual instances of `TestState` deterministic, which
helps with debugging.

Cargo.lock

@@ -3069,6 +3069,7 @@ dependencies = [
  "pasta_curves",
  "proptest",
  "prost",
+ "rand_chacha",
  "rand_core",
  "regex",
  "rusqlite",

Cargo.toml

@@ -109,6 +109,7 @@ lazy_static = "1"
 assert_matches = "1.5"
 criterion = "0.4"
 proptest = "1"
+rand_chacha = "0.3"
 rand_xorshift = "0.3"
 
 # ZIP 32

zcash_client_sqlite/Cargo.toml

@@ -83,6 +83,7 @@ pasta_curves.workspace = true
 shardtree = { workspace = true, features = ["legacy-api", "test-dependencies"] }
 nonempty.workspace = true
 proptest.workspace = true
+rand_chacha.workspace = true
 rand_core.workspace = true
 regex = "1.4"
 tempfile = "3.5.0"

zcash_client_sqlite/src/testing.rs

@@ -7,7 +7,8 @@ use std::fs::File;
 
 use nonempty::NonEmpty;
 use prost::Message;
-use rand_core::{CryptoRng, OsRng, RngCore};
+use rand_chacha::ChaChaRng;
+use rand_core::{CryptoRng, RngCore, SeedableRng};
 use rusqlite::{params, Connection};
 use secrecy::{Secret, SecretVec};
 use tempfile::NamedTempFile;
@@ -102,6 +103,7 @@ pub(crate) struct TestBuilder<Cache> {
     network: LocalNetwork,
     cache: Cache,
     test_account_birthday: Option<AccountBirthday>,
+    rng: ChaChaRng,
 }
 
 impl TestBuilder<()> {
@@ -124,6 +126,7 @@ impl TestBuilder<()> {
             },
             cache: (),
             test_account_birthday: None,
+            rng: ChaChaRng::seed_from_u64(0),
         }
     }
 
@@ -133,6 +136,7 @@ impl TestBuilder<()> {
             network: self.network,
             cache: BlockCache::new(),
             test_account_birthday: self.test_account_birthday,
+            rng: self.rng,
         }
     }
 
@@ -143,6 +147,7 @@ impl TestBuilder<()> {
             network: self.network,
             cache: FsBlockCache::new(),
             test_account_birthday: self.test_account_birthday,
+            rng: self.rng,
         }
     }
 }
@@ -176,6 +181,7 @@ impl<Cache> TestBuilder<Cache> {
             _data_file: data_file,
             db_data,
             test_account,
+            rng: self.rng,
         }
     }
 }
@@ -236,6 +242,7 @@ pub(crate) struct TestState<Cache> {
         UnifiedSpendingKey,
         AccountBirthday,
     )>,
+    rng: ChaChaRng,
 }
 
 impl<Cache: TestCache> TestState<Cache>
@@ -305,6 +312,7 @@ where
             value,
             initial_sapling_tree_size,
             initial_orchard_tree_size,
+            &mut self.rng,
         );
         let res = self.cache.insert(&cb);
 
@@ -346,6 +354,7 @@ where
             value,
             cached_block.sapling_end_size,
             cached_block.orchard_end_size,
+            &mut self.rng,
         );
         let res = self.cache.insert(&cb);
 
@@ -397,6 +406,7 @@ where
             tx,
             cached_block.sapling_end_size,
             cached_block.orchard_end_size,
+            &mut self.rng,
         );
         let res = self.cache.insert(&cb);
 
@@ -1150,10 +1160,8 @@ fn fake_compact_block<P: consensus::Parameters, Fvk: TestFvk>(
     value: NonNegativeAmount,
     initial_sapling_tree_size: u32,
     initial_orchard_tree_size: u32,
+    mut rng: impl RngCore + CryptoRng,
 ) -> (CompactBlock, Fvk::Nullifier) {
-    // Create a fake Note for the account
-    let mut rng = OsRng;
-
     // Create a fake CompactBlock containing the note
     let mut ctx = fake_compact_tx(&mut rng);
     let nf = fvk.add_output(
@@ -1172,6 +1180,7 @@ fn fake_compact_block<P: consensus::Parameters, Fvk: TestFvk>(
         prev_hash,
         initial_sapling_tree_size,
         initial_orchard_tree_size,
+        rng,
     );
     (cb, nf)
 }
@@ -1184,6 +1193,7 @@ fn fake_compact_block_from_tx(
     tx: &Transaction,
     initial_sapling_tree_size: u32,
     initial_orchard_tree_size: u32,
+    rng: impl RngCore,
 ) -> CompactBlock {
     // Create a fake CompactTx containing the transaction.
     let mut ctx = CompactTx {
@@ -1214,6 +1224,7 @@ fn fake_compact_block_from_tx(
         prev_hash,
         initial_sapling_tree_size,
         initial_orchard_tree_size,
+        rng,
     )
 }
 
@@ -1230,8 +1241,8 @@ fn fake_compact_block_spending<P: consensus::Parameters, Fvk: TestFvk>(
     value: NonNegativeAmount,
     initial_sapling_tree_size: u32,
     initial_orchard_tree_size: u32,
+    mut rng: impl RngCore + CryptoRng,
 ) -> CompactBlock {
-    let mut rng = OsRng;
     let mut ctx = fake_compact_tx(&mut rng);
 
     // Create a fake spend and a fake Note for the change
@@ -1313,6 +1324,7 @@ fn fake_compact_block_spending<P: consensus::Parameters, Fvk: TestFvk>(
         prev_hash,
         initial_sapling_tree_size,
         initial_orchard_tree_size,
+        rng,
     )
 }
 
@@ -1322,8 +1334,8 @@ fn fake_compact_block_from_compact_tx(
     prev_hash: BlockHash,
     initial_sapling_tree_size: u32,
     initial_orchard_tree_size: u32,
+    mut rng: impl RngCore,
 ) -> CompactBlock {
-    let mut rng = OsRng;
     let mut cb = CompactBlock {
         hash: {
             let mut hash = vec![0; 32];