feat: abi encoder

.gitignore

@@ -11,6 +11,7 @@ build/
 *.exe
 *.dll
 nimble.paths
+nimbledeps
 
 node_modules
 nohup.out

README.md

@@ -35,6 +35,56 @@ Then you should run `./simulator.sh` which runs `hardhat node`
 
 This creates a local simulated Ethereum network on your local machine and the tests will use this for their E2E processing
 
+### ABI encoder / decoder
+
+Implements encoding of parameters according to the Ethereum
+[Contract ABI Specification][1] using nim-serialization interface.
+
+Usage
+-----
+
+```nim
+import
+  serialization,
+  stint,
+  web3/[encoding, decoding]
+
+# encode unsigned integers, booleans, enums
+Abi.encode(42'u8)
+
+# encode uint256
+Abi.encode(42.u256)
+
+# encode byte arrays and sequences
+Abi.encode([1'u8, 2'u8, 3'u8])
+Abi.encode(@[1'u8, 2'u8, 3'u8])
+
+# encode tuples
+Abi.encode( (42'u8, @[1'u8, 2'u8, 3'u8], true) )
+
+# decode values of different types
+Abi.decode(bytes, uint8)
+Abi.decode(bytes, UInt256)
+Abi.decode(bytes, array[3, uint8])
+Abi.decode(bytes, seq[uint8])
+
+# decode tuples
+Abi.decode(bytes, (uint32, bool, seq[byte]))
+
+# custom type
+type Contract = object
+  a: uint64
+  b {.dontSerialize.}: string
+  c: bool
+
+let encoded = Abi.encode(x)
+let decoded = Abi.decode(encoded, Contract)
+
+# encoded.a == decoded.a
+# encoded.b == ""
+# encoded.c == decoded.c
+```
+
 ## License
 
 Licensed and distributed under either of
@@ -46,3 +96,5 @@ or
 - Apache License, Version 2.0, ([LICENSE-APACHEv2](LICENSE-APACHEv2) or http://www.apache.org/licenses/LICENSE-2.0)
 
 at your option. This file may not be copied, modified, or distributed except according to those terms.
+
+[1]: https://docs.soliditylang.org/en/latest/abi-spec.html

ci-test.sh

@@ -1,8 +1,10 @@
 #!/bin/bash
 
 set -ex
-npm install hardhat
-touch hardhat.config.js
+npm install hardhat@3
+npm pkg set type="module"
+echo "export default {};" > hardhat.config.js
+npx hardhat --version
 nohup npx hardhat node &
 nimble install -y --depsOnly
 

tests/all_tests.nim

@@ -19,5 +19,9 @@ import
   test_signed_tx,
   test_execution_types,
   test_string_decoder,
+  test_abi_utils,
+  test_encoding,
+  test_decoding,
+  test_abi_serialization,
   test_contract_dsl,
-  test_execution_api
+  test_execution_api

tests/test_abi_serialization.nim

@@ -0,0 +1,67 @@
+import
+    std/unittest,
+    serialization,
+    std/random,
+    ../web3/encoding,
+    ../web3/decoding,
+    ../web3/eth_api_types,
+    ../web3/abi_serialization
+
+type Contract = object
+  a: uint64
+  b {.dontSerialize.}: string
+  c: bool
+  d: string
+
+type StorageDeal = object
+  client: array[20, byte]
+  provider: array[20, byte]
+  cid: array[32, byte]
+  size: uint64
+  duration: uint64
+  pricePerByte: UInt256
+  signature: array[65, byte]
+  metadata: string
+
+proc randomBytes[N: static int](): array[N, byte] =
+  var a: array[N, byte]
+  for b in a.mitems:
+      b = rand(byte)
+  return a
+
+suite "ABI serialization":
+  test "encode and decode custom type":
+    let x = Contract(a: 1, b: "SECRET", c: true, d: "hello")
+
+    let encoded = Abi.encode(x)
+    check encoded == Abi.encode((x.a, x.c, x.d))
+
+    let decoded = Abi.decode(encoded, Contract)
+    check decoded.a == x.a
+    check decoded.b == ""
+    check decoded.c == x.c
+    check decoded.d == x.d
+
+  test "encode and decode complex type":
+    let deal = StorageDeal(
+      client: randomBytes[20](),
+      provider: randomBytes[20](),
+      cid: randomBytes[32](),
+      size: 1024'u64,
+      duration: 365'u64,
+      pricePerByte: 1000.u256,
+      signature: randomBytes[65](),
+      metadata: "Sample metadata for storage deal"
+    )
+
+    let encoded = Abi.encode(deal)
+    let decoded = Abi.decode(encoded, StorageDeal)
+
+    check decoded.client == deal.client
+    check decoded.provider == deal.provider
+    check decoded.cid == deal.cid
+    check decoded.size == deal.size
+    check decoded.duration == deal.duration
+    check decoded.pricePerByte == deal.pricePerByte
+    check decoded.signature == deal.signature
+    check decoded.metadata == deal.metadata

tests/test_abi_utils.nim

@@ -0,0 +1,15 @@
+
+import
+    std/unittest,
+    ../web3/abi_utils
+
+suite "ABI utils":
+    test "can determine whether types are dynamic or static":
+        check static isStatic(uint8)
+        check static isDynamic(seq[byte])
+        check static isStatic(array[2, array[2, byte]])
+        check static isDynamic(array[2, seq[byte]])
+        check static isStatic((uint8, bool))
+        check static isDynamic((uint8, seq[byte]))
+        check static isStatic((uint8, (bool, uint8)))
+        check static isDynamic((uint8, (bool, seq[byte])))

tests/test_contract_dsl.nim

@@ -11,6 +11,7 @@ import
   pkg/unittest2,
   stew/byteutils,
   stint,
+  ../web3/encoding,
   ../web3/contract_dsl
 
 type