replaced manual TestRandom implementation with macro when possible; fixed typo in TestRandom macro (lighthouse-246)

eth2/types/Cargo.toml

@@ -20,6 +20,7 @@ slog = "^2.2.3"
 ssz = { path = "../utils/ssz" }
 ssz_derive = { path = "../utils/ssz_derive" }
 swap_or_not_shuffle = { path = "../utils/swap_or_not_shuffle" }
+test_random_derive = { path = "../utils/test_random_derive" }
 
 [dev-dependencies]
 env_logger = "0.6.0"

eth2/types/src/attestation.rs

@@ -4,8 +4,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, Clone, PartialEq, Serialize, Encode, Decode)]
+#[derive(Debug, Clone, PartialEq, Serialize, Encode, Decode, TestRandom)]
 pub struct Attestation {
     pub aggregation_bitfield: Bitfield,
     pub data: AttestationData,
@@ -45,17 +46,6 @@ impl TreeHash for Attestation {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for Attestation {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            data: <_>::random_for_test(rng),
-            aggregation_bitfield: <_>::random_for_test(rng),
-            custody_bitfield: <_>::random_for_test(rng),
-            aggregate_signature: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/attestation_data.rs

@@ -4,6 +4,7 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
 pub const SSZ_ATTESTION_DATA_LENGTH: usize = {
     8 +             // slot
@@ -16,7 +17,7 @@ pub const SSZ_ATTESTION_DATA_LENGTH: usize = {
     32 // justified_block_root
 };
 
-#[derive(Debug, Clone, PartialEq, Default, Serialize, Hash, Encode, Decode)]
+#[derive(Debug, Clone, PartialEq, Default, Serialize, Hash, Encode, Decode, TestRandom)]
 pub struct AttestationData {
     pub slot: Slot,
     pub shard: u64,
@@ -59,21 +60,6 @@ impl TreeHash for AttestationData {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for AttestationData {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            slot: <_>::random_for_test(rng),
-            shard: <_>::random_for_test(rng),
-            beacon_block_root: <_>::random_for_test(rng),
-            epoch_boundary_root: <_>::random_for_test(rng),
-            shard_block_root: <_>::random_for_test(rng),
-            latest_crosslink: <_>::random_for_test(rng),
-            justified_epoch: <_>::random_for_test(rng),
-            justified_block_root: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/attester_slashing.rs

@@ -3,8 +3,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TestRandom)]
 pub struct AttesterSlashing {
     pub slashable_attestation_1: SlashableAttestation,
     pub slashable_attestation_2: SlashableAttestation,
@@ -19,15 +20,6 @@ impl TreeHash for AttesterSlashing {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for AttesterSlashing {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            slashable_attestation_1: <_>::random_for_test(rng),
-            slashable_attestation_2: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/beacon_block.rs

@@ -5,8 +5,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TestRandom)]
 pub struct BeaconBlock {
     pub slot: Slot,
     pub parent_root: Hash256,
@@ -74,20 +75,6 @@ impl TreeHash for BeaconBlock {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for BeaconBlock {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            slot: <_>::random_for_test(rng),
-            parent_root: <_>::random_for_test(rng),
-            state_root: <_>::random_for_test(rng),
-            randao_reveal: <_>::random_for_test(rng),
-            eth1_data: <_>::random_for_test(rng),
-            signature: <_>::random_for_test(rng),
-            body: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/beacon_block_body.rs

@@ -4,8 +4,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, PartialEq, Clone, Default, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Default, Serialize, Encode, Decode, TestRandom)]
 pub struct BeaconBlockBody {
     pub proposer_slashings: Vec<ProposerSlashing>,
     pub attester_slashings: Vec<AttesterSlashing>,
@@ -26,18 +27,6 @@ impl TreeHash for BeaconBlockBody {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for BeaconBlockBody {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            proposer_slashings: <_>::random_for_test(rng),
-            attester_slashings: <_>::random_for_test(rng),
-            attestations: <_>::random_for_test(rng),
-            deposits: <_>::random_for_test(rng),
-            exits: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/beacon_state.rs

@@ -12,6 +12,7 @@ use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
 use swap_or_not_shuffle::get_permutated_index;
+use test_random_derive::TestRandom;
 
 mod tests;
 
@@ -52,7 +53,7 @@ macro_rules! safe_sub_assign {
     };
 }
 
-#[derive(Debug, PartialEq, Clone, Default, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Default, Serialize, Encode, Decode, TestRandom)]
 pub struct BeaconState {
     // Misc
     pub slot: Slot,
@@ -1003,35 +1004,3 @@ impl TreeHash for BeaconState {
         hash(&result)
     }
 }
-
-impl<T: RngCore> TestRandom<T> for BeaconState {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            slot: <_>::random_for_test(rng),
-            genesis_time: <_>::random_for_test(rng),
-            fork: <_>::random_for_test(rng),
-            validator_registry: <_>::random_for_test(rng),
-            validator_balances: <_>::random_for_test(rng),
-            validator_registry_update_epoch: <_>::random_for_test(rng),
-            latest_randao_mixes: <_>::random_for_test(rng),
-            previous_epoch_start_shard: <_>::random_for_test(rng),
-            current_epoch_start_shard: <_>::random_for_test(rng),
-            previous_calculation_epoch: <_>::random_for_test(rng),
-            current_calculation_epoch: <_>::random_for_test(rng),
-            previous_epoch_seed: <_>::random_for_test(rng),
-            current_epoch_seed: <_>::random_for_test(rng),
-            previous_justified_epoch: <_>::random_for_test(rng),
-            justified_epoch: <_>::random_for_test(rng),
-            justification_bitfield: <_>::random_for_test(rng),
-            finalized_epoch: <_>::random_for_test(rng),
-            latest_crosslinks: <_>::random_for_test(rng),
-            latest_block_roots: <_>::random_for_test(rng),
-            latest_index_roots: <_>::random_for_test(rng),
-            latest_penalized_balances: <_>::random_for_test(rng),
-            latest_attestations: <_>::random_for_test(rng),
-            batched_block_roots: <_>::random_for_test(rng),
-            latest_eth1_data: <_>::random_for_test(rng),
-            eth1_data_votes: <_>::random_for_test(rng),
-        }
-    }
-}

eth2/types/src/casper_slashing.rs

@@ -4,8 +4,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TestRandom)]
 pub struct CasperSlashing {
     pub slashable_vote_data_1: SlashableVoteData,
     pub slashable_vote_data_2: SlashableVoteData,
@@ -20,15 +21,6 @@ impl TreeHash for CasperSlashing {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for CasperSlashing {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            slashable_vote_data_1: <_>::random_for_test(rng),
-            slashable_vote_data_2: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/crosslink.rs

@@ -4,8 +4,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, Clone, PartialEq, Default, Serialize, Hash, Encode, Decode)]
+#[derive(Debug, Clone, PartialEq, Default, Serialize, Hash, Encode, Decode, TestRandom)]
 pub struct Crosslink {
     pub epoch: Epoch,
     pub shard_block_root: Hash256,
@@ -30,15 +31,6 @@ impl TreeHash for Crosslink {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for Crosslink {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            epoch: <_>::random_for_test(rng),
-            shard_block_root: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/deposit.rs

@@ -4,8 +4,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TestRandom)]
 pub struct Deposit {
     pub branch: Vec<Hash256>,
     pub index: u64,
@@ -22,16 +23,6 @@ impl TreeHash for Deposit {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for Deposit {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            branch: <_>::random_for_test(rng),
-            index: <_>::random_for_test(rng),
-            deposit_data: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/deposit_data.rs

@@ -4,8 +4,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TestRandom)]
 pub struct DepositData {
     pub amount: u64,
     pub timestamp: u64,
@@ -22,16 +23,6 @@ impl TreeHash for DepositData {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for DepositData {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            amount: <_>::random_for_test(rng),
-            timestamp: <_>::random_for_test(rng),
-            deposit_input: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/deposit_input.rs

@@ -5,8 +5,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TestRandom)]
 pub struct DepositInput {
     pub pubkey: PublicKey,
     pub withdrawal_credentials: Hash256,
@@ -23,16 +24,6 @@ impl TreeHash for DepositInput {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for DepositInput {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            pubkey: <_>::random_for_test(rng),
-            withdrawal_credentials: <_>::random_for_test(rng),
-            proof_of_possession: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/eth1_data.rs

@@ -4,9 +4,10 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
 // Note: this is refer to as DepositRootVote in specs
-#[derive(Debug, PartialEq, Clone, Default, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Default, Serialize, Encode, Decode, TestRandom)]
 pub struct Eth1Data {
     pub deposit_root: Hash256,
     pub block_hash: Hash256,
@@ -21,15 +22,6 @@ impl TreeHash for Eth1Data {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for Eth1Data {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            deposit_root: <_>::random_for_test(rng),
-            block_hash: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/eth1_data_vote.rs

@@ -4,9 +4,10 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
 // Note: this is refer to as DepositRootVote in specs
-#[derive(Debug, PartialEq, Clone, Default, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Default, Serialize, Encode, Decode, TestRandom)]
 pub struct Eth1DataVote {
     pub eth1_data: Eth1Data,
     pub vote_count: u64,
@@ -21,15 +22,6 @@ impl TreeHash for Eth1DataVote {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for Eth1DataVote {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            eth1_data: <_>::random_for_test(rng),
-            vote_count: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/exit.rs

@@ -4,8 +4,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TestRandom)]
 pub struct Exit {
     pub epoch: Epoch,
     pub validator_index: u64,
@@ -22,16 +23,6 @@ impl TreeHash for Exit {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for Exit {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            epoch: <_>::random_for_test(rng),
-            validator_index: <_>::random_for_test(rng),
-            signature: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/fork.rs

@@ -3,8 +3,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, Clone, PartialEq, Default, Serialize, Encode, Decode)]
+#[derive(Debug, Clone, PartialEq, Default, Serialize, Encode, Decode, TestRandom)]
 pub struct Fork {
     pub previous_version: u64,
     pub current_version: u64,
@@ -21,16 +22,6 @@ impl TreeHash for Fork {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for Fork {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            previous_version: <_>::random_for_test(rng),
-            current_version: <_>::random_for_test(rng),
-            epoch: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/pending_attestation.rs

@@ -4,8 +4,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, Clone, PartialEq, Serialize, Encode, Decode)]
+#[derive(Debug, Clone, PartialEq, Serialize, Encode, Decode, TestRandom)]
 pub struct PendingAttestation {
     pub aggregation_bitfield: Bitfield,
     pub data: AttestationData,
@@ -24,17 +25,6 @@ impl TreeHash for PendingAttestation {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for PendingAttestation {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            data: <_>::random_for_test(rng),
-            aggregation_bitfield: <_>::random_for_test(rng),
-            custody_bitfield: <_>::random_for_test(rng),
-            inclusion_slot: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/proposal_signed_data.rs

@@ -4,8 +4,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, PartialEq, Clone, Default, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Default, Serialize, Encode, Decode, TestRandom)]
 pub struct ProposalSignedData {
     pub slot: Slot,
     pub shard: u64,
@@ -22,16 +23,6 @@ impl TreeHash for ProposalSignedData {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for ProposalSignedData {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            slot: <_>::random_for_test(rng),
-            shard: <_>::random_for_test(rng),
-            block_root: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/proposer_slashing.rs

@@ -5,8 +5,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TestRandom)]
 pub struct ProposerSlashing {
     pub proposer_index: u64,
     pub proposal_data_1: ProposalSignedData,
@@ -27,18 +28,6 @@ impl TreeHash for ProposerSlashing {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for ProposerSlashing {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            proposer_index: <_>::random_for_test(rng),
-            proposal_data_1: <_>::random_for_test(rng),
-            proposal_signature_1: <_>::random_for_test(rng),
-            proposal_data_2: <_>::random_for_test(rng),
-            proposal_signature_2: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/shard_reassignment_record.rs

@@ -3,8 +3,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TestRandom)]
 pub struct ShardReassignmentRecord {
     pub validator_index: u64,
     pub shard: u64,
@@ -21,16 +22,6 @@ impl TreeHash for ShardReassignmentRecord {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for ShardReassignmentRecord {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            validator_index: <_>::random_for_test(rng),
-            shard: <_>::random_for_test(rng),
-            slot: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/slashable_attestation.rs

@@ -3,8 +3,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TestRandom)]
 pub struct SlashableAttestation {
     pub validator_indices: Vec<u64>,
     pub data: AttestationData,
@@ -23,17 +24,6 @@ impl TreeHash for SlashableAttestation {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for SlashableAttestation {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            validator_indices: <_>::random_for_test(rng),
-            data: <_>::random_for_test(rng),
-            custody_bitfield: <_>::random_for_test(rng),
-            aggregate_signature: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/slashable_vote_data.rs

@@ -6,8 +6,9 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode)]
+#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TestRandom)]
 pub struct SlashableVoteData {
     pub custody_bit_0_indices: Vec<u32>,
     pub custody_bit_1_indices: Vec<u32>,
@@ -47,17 +48,6 @@ impl TreeHash for SlashableVoteData {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for SlashableVoteData {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            custody_bit_0_indices: <_>::random_for_test(rng),
-            custody_bit_1_indices: <_>::random_for_test(rng),
-            data: <_>::random_for_test(rng),
-            aggregate_signature: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/types/src/validator_registry_delta_block.rs

@@ -4,9 +4,10 @@ use rand::RngCore;
 use serde_derive::Serialize;
 use ssz::{hash, TreeHash};
 use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
 
 // The information gathered from the PoW chain validator registration function.
-#[derive(Debug, Clone, PartialEq, Serialize, Encode, Decode)]
+#[derive(Debug, Clone, PartialEq, Serialize, Encode, Decode, TestRandom)]
 pub struct ValidatorRegistryDeltaBlock {
     pub latest_registry_delta_root: Hash256,
     pub validator_index: u32,
@@ -40,18 +41,6 @@ impl TreeHash for ValidatorRegistryDeltaBlock {
     }
 }
 
-impl<T: RngCore> TestRandom<T> for ValidatorRegistryDeltaBlock {
-    fn random_for_test(rng: &mut T) -> Self {
-        Self {
-            latest_registry_delta_root: <_>::random_for_test(rng),
-            validator_index: <_>::random_for_test(rng),
-            pubkey: <_>::random_for_test(rng),
-            slot: <_>::random_for_test(rng),
-            flag: <_>::random_for_test(rng),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

eth2/utils/test_random_derive/src/lib.rs

@@ -6,22 +6,22 @@ use syn::{parse_macro_input, DeriveInput};
 
 #[proc_macro_derive(TestRandom)]
 pub fn test_random_derive(input: TokenStream) -> TokenStream {
-    let ast = parse_macro_input!(input as DeriveInput);
-    let name = &ast.ident;
+    let derived_input = parse_macro_input!(input as DeriveInput);
+    let name = &derived_input.ident;
 
-    let struct_data = match &ast.data {
+    let struct_data = match &derived_input.data {
         syn::Data::Struct(s) => s,
         _ => panic!("test_random_derive only supports structs."),
     };
 
-    let field_names = get_named_field_idents_and_types(&struct_data);
+    let field_names = get_named_field_idents(&struct_data);
 
     let output = quote! {
         impl<T: RngCore> TestRandom<T> for #name {
             fn random_for_test(rng: &mut T) -> Self {
                Self {
                     #(
-                        #field_names: <_>::random_for_test(rng)
+                        #field_names: <_>::random_for_test(rng),
                     )*
                }
             }
@@ -31,7 +31,7 @@ pub fn test_random_derive(input: TokenStream) -> TokenStream {
     output.into()
 }
 
-fn get_named_field_idents_and_types(struct_data: &syn::DataStruct) -> Vec<(&syn::Ident)> {
+fn get_named_field_idents(struct_data: &syn::DataStruct) -> Vec<(&syn::Ident)> {
     struct_data
         .fields
         .iter()