From c08698bffeebf2d2e96a643bbfb14292394c6edd Mon Sep 17 00:00:00 2001
From: Dustin Brody <tersec@users.noreply.github.com>
Date: Thu, 14 Nov 2019 18:37:51 +0100
Subject: [PATCH] scaffolding to remove last vestiges of
 get_committee_count(...), SHARD_COUNT, and rest of that 0.8.x infrastructure;
 this demonstrates equivalence between two, before discarding old code

---
 beacon_chain/beacon_node.nim                 | 20 ++++++++++++++------
 beacon_chain/spec/beaconstate.nim            |  9 +++++----
 tests/simulation/run_node.sh                 |  2 ++
 tests/simulation/start.sh                    |  2 ++
 tests/spec_block_processing/test_genesis.nim |  6 +++---
 tests/testutil.nim                           | 19 ++++++++++---------
 6 files changed, 36 insertions(+), 22 deletions(-)

diff --git a/beacon_chain/beacon_node.nim b/beacon_chain/beacon_node.nim
index 77b573dd6..c3a9dce73 100644
--- a/beacon_chain/beacon_node.nim
+++ b/beacon_chain/beacon_node.nim
@@ -547,20 +547,28 @@ proc handleAttestations(node: BeaconNode, head: BlockRef, slot: Slot) =
     let
       epoch = compute_epoch_at_slot(slot)
       committees_per_slot =
+        # get_committee_count_at_slot(state, slot)
         get_committee_count_at_slot(state, epoch.compute_start_slot_at_epoch)
       offset = committees_per_slot * (slot mod SLOTS_PER_EPOCH)
       slot_start_shard = (get_start_shard(state, epoch) + offset) mod SHARD_COUNT
 
-    for i in 0'u64..<committees_per_slot:
+    for committee_index in 0'u64..<committees_per_slot:
       let
-        shard = Shard((slot_start_shard + i) mod SHARD_COUNT)
-        committee = get_crosslink_committee(state, epoch, shard, cache)
+        shard = Shard((slot_start_shard + committee_index) mod SHARD_COUNT)
+        shard_committee = get_crosslink_committee(state, epoch, shard, cache)
+        committee = get_beacon_committee(state, slot, committee_index, cache)
 
-      for i, validatorIdx in committee:
+      for index_in_committee, validatorIdx in committee:
         let validator = node.getAttachedValidator(state, validatorIdx)
         if validator != nil:
-          let ad = makeAttestationData(state, shard, blck.root)
-          attestations.add((ad, committee.len, i, validator))
+          let ad = makeAttestationData(state, slot, committee_index, blck.root)
+          let
+            (hm_slot, hm_index) = get_slot_and_index(state, epoch, shard)
+            shard_ad = makeAttestationData(state, hm_slot, hm_index, blck.root)
+          doAssert slot == hm_slot
+          doAssert hm_index == committee_index
+          attestations.add((ad, committee.len, index_in_committee, validator))
+          #attestations.add((shard_ad, committee.len, index_in_committee, validator))
 
     for a in attestations:
       traceAsyncErrors sendAttestation(
diff --git a/beacon_chain/spec/beaconstate.nim b/beacon_chain/spec/beaconstate.nim
index 07634aa20..99dadca82 100644
--- a/beacon_chain/spec/beaconstate.nim
+++ b/beacon_chain/spec/beaconstate.nim
@@ -487,7 +487,7 @@ proc process_attestation*(
     false
 
 proc makeAttestationData*(
-    state: BeaconState, shard: uint64,
+    state: BeaconState, slot: Slot, committee_index: uint64,
     beacon_block_root: Eth2Digest): AttestationData =
   ## Create an attestation / vote for the block `beacon_block_root` using the
   ## data in `state` to fill in the rest of the fields.
@@ -502,11 +502,12 @@ proc makeAttestationData*(
     epoch_boundary_block_root =
       if start_slot == state.slot: beacon_block_root
       else: get_block_root_at_slot(state, start_slot)
-    (a_slot, a_index) = get_slot_and_index(state, current_epoch, shard)
+
+  doAssert slot.compute_epoch_at_slot == current_epoch
 
   AttestationData(
-    slot: a_slot,
-    index: a_index,
+    slot: slot,
+    index: committee_index,
     beacon_block_root: beacon_block_root,
     source: state.current_justified_checkpoint,
     target: Checkpoint(
diff --git a/tests/simulation/run_node.sh b/tests/simulation/run_node.sh
index 8ec92ff40..ba6fab852 100755
--- a/tests/simulation/run_node.sh
+++ b/tests/simulation/run_node.sh
@@ -6,9 +6,11 @@ NODE_ID=${1}
 shift
 
 # Read in variables
+# shellcheck source=/dev/null
 source "$(dirname "$0")/vars.sh"
 
 # set up the environment
+# shellcheck source=/dev/null
 source "${SIM_ROOT}/../../env.sh"
 
 cd "$GIT_ROOT"
diff --git a/tests/simulation/start.sh b/tests/simulation/start.sh
index 6a16f50bb..7a59a3e74 100755
--- a/tests/simulation/start.sh
+++ b/tests/simulation/start.sh
@@ -3,9 +3,11 @@
 set -eo pipefail
 
 # Read in variables
+# shellcheck source=/dev/null
 source "$(dirname "$0")/vars.sh"
 
 # set up the environment
+# shellcheck source=/dev/null
 source "${SIM_ROOT}/../../env.sh"
 
 cd "$SIM_ROOT"
diff --git a/tests/spec_block_processing/test_genesis.nim b/tests/spec_block_processing/test_genesis.nim
index 3387fac68..06b98f4d2 100644
--- a/tests/spec_block_processing/test_genesis.nim
+++ b/tests/spec_block_processing/test_genesis.nim
@@ -31,21 +31,21 @@ import
 
 suite "[Unit - Spec - Genesis] Genesis block checks " & preset():
   test "is_valid_genesis_state for a valid state":
-    let state = initGenesisState(
+    discard initGenesisState(
       num_validators = MIN_GENESIS_ACTIVE_VALIDATOR_COUNT,
       genesis_time = MIN_GENESIS_TIME
     )
     discard "TODO"
 
   test "Invalid genesis time":
-    let state = initGenesisState(
+    discard initGenesisState(
       num_validators = MIN_GENESIS_ACTIVE_VALIDATOR_COUNT,
       genesis_time = MIN_GENESIS_TIME.uint64 - 1
     )
     discard "TODO"
 
   test "Not enough validators":
-    let state = initGenesisState(
+    discard initGenesisState(
       num_validators = MIN_GENESIS_ACTIVE_VALIDATOR_COUNT.uint64 - 1,
       genesis_time = MIN_GENESIS_TIME.uint64 - 1
     )
diff --git a/tests/testutil.nim b/tests/testutil.nim
index 8c7258a72..b31839733 100644
--- a/tests/testutil.nim
+++ b/tests/testutil.nim
@@ -157,28 +157,29 @@ proc makeBlock*(
   var next_state = state
   addBlock(next_state, previous_block_root, body)
 
-proc find_shard_committee(
+proc find_beacon_committee(
     state: BeaconState, validator_index: ValidatorIndex): auto =
   let epoch = compute_epoch_at_slot(state.slot)
   var cache = get_empty_per_epoch_cache()
-  for shard in 0'u64 ..< get_committee_count_at_slot(
+  for epoch_committee_index in 0'u64 ..< get_committee_count_at_slot(
       state, epoch.compute_start_slot_at_epoch) * SLOTS_PER_EPOCH:
-    let committee = get_crosslink_committee(state, epoch,
-      (shard + get_start_shard(state, epoch)) mod SHARD_COUNT, cache)
+    let
+      slot = ((epoch_committee_index mod SLOTS_PER_EPOCH) +
+        epoch.compute_start_slot_at_epoch.uint64).Slot
+      index = epoch_committee_index div SLOTS_PER_EPOCH
+      committee = get_beacon_committee(state, slot, index, cache)
     if validator_index in committee:
-      return (committee, shard)
+      return (committee, slot, index)
   doAssert false
 
 proc makeAttestation*(
     state: BeaconState, beacon_block_root: Eth2Digest,
     validator_index: ValidatorIndex, flags: UpdateFlags = {}): Attestation =
   let
-    (committee, shard) = find_shard_committee(state, validator_index)
+    (committee, slot, index) = find_beacon_committee(state, validator_index)
     validator = state.validators[validator_index]
     sac_index = committee.find(validator_index)
-    data = makeAttestationData(state,
-      (shard + get_start_shard(state, compute_epoch_at_slot(state.slot))) mod
-      SHARD_COUNT, beacon_block_root)
+    data = makeAttestationData(state, slot, index, beacon_block_root)
 
   doAssert sac_index != -1, "find_shard_committee should guarantee this"