Directory Restructure (#1163)

* Move tests -> testing

* Directory restructure

* Update Cargo.toml during restructure

* Update Makefile during restructure

* Fix arbitrary path

beacon_node/operation_pool/src/attestation_id.rs

@@ -0,0 +1,45 @@
+use serde_derive::{Deserialize, Serialize};
+use ssz::ssz_encode;
+use ssz_derive::{Decode, Encode};
+use types::{AttestationData, ChainSpec, Domain, Epoch, Fork, Hash256};
+
+/// Serialized `AttestationData` augmented with a domain to encode the fork info.
+#[derive(
+    PartialEq, Eq, Clone, Hash, Debug, PartialOrd, Ord, Encode, Decode, Serialize, Deserialize,
+)]
+pub struct AttestationId {
+    v: Vec<u8>,
+}
+
+/// Number of domain bytes that the end of an attestation ID is padded with.
+const DOMAIN_BYTES_LEN: usize = std::mem::size_of::<Hash256>();
+
+impl AttestationId {
+    pub fn from_data(
+        attestation: &AttestationData,
+        fork: &Fork,
+        genesis_validators_root: Hash256,
+        spec: &ChainSpec,
+    ) -> Self {
+        let mut bytes = ssz_encode(attestation);
+        let epoch = attestation.target.epoch;
+        bytes.extend_from_slice(
+            AttestationId::compute_domain_bytes(epoch, fork, genesis_validators_root, spec)
+                .as_bytes(),
+        );
+        AttestationId { v: bytes }
+    }
+
+    pub fn compute_domain_bytes(
+        epoch: Epoch,
+        fork: &Fork,
+        genesis_validators_root: Hash256,
+        spec: &ChainSpec,
+    ) -> Hash256 {
+        spec.get_domain(epoch, Domain::BeaconAttester, fork, genesis_validators_root)
+    }
+
+    pub fn domain_bytes_match(&self, domain_bytes: &Hash256) -> bool {
+        &self.v[self.v.len() - DOMAIN_BYTES_LEN..] == domain_bytes.as_bytes()
+    }
+}