Return Option[T] instead of raising exceptions

nitro/abi.nim

@@ -13,6 +13,8 @@ type
     head: Slice[int]
     tail: seq[byte]
 
+{.push raises:[].}
+
 proc write*[T](encoder: var AbiEncoder, value: T)
 proc encode*[T](_: type AbiEncoder, value: T): seq[byte]
 

nitro/channel.nim

@@ -10,6 +10,8 @@ type
     participants*: seq[EthAddress]
     chainId*: UInt256
 
+{.push raises:[].}
+
 proc getChannelId*(channel: Channel): array[32, byte] =
   var encoder= AbiEncoder.init()
   encoder.startTuple()

nitro/helpers.nim

@@ -0,0 +1,13 @@
+import std/options
+import pkg/stew/results
+
+export options
+export results
+
+{.push raises:[].}
+
+proc toOption*[T, E](res: Result[T, E]): Option[T] =
+  if res.isOk:
+    res.value.some
+  else:
+    T.none

nitro/outcome.nim

@@ -25,6 +25,8 @@ type
     targetChannelId*: array[32, byte]
     destinations*: seq[array[32, byte]]
 
+{.push raises:[].}
+
 proc encode*(encoder: var AbiEncoder, guarantee: Guarantee) =
   encoder.startTuple()
   encoder.startTuple()

nitro/signature.nim

@@ -1,8 +1,11 @@
+import std/options
 import pkg/nimcrypto
 import pkg/secp256k1
 import pkg/stew/byteutils
 import ./state
+import ./helpers
 
+export options
 export toPublicKey
 
 type
@@ -10,6 +13,8 @@ type
   PublicKey* = SkPublicKey
   Signature* = SkRecoverableSignature
 
+{.push raises:[].}
+
 proc rng(data: var openArray[byte]): bool =
   randomBytes(data) == data.len
 
@@ -19,8 +24,8 @@ proc random*(_: type PrivateKey): PrivateKey =
 proc `$`*(key: PrivateKey): string =
   key.toHex()
 
-proc parse*(_: type PrivateKey, s: string): PrivateKey =
-  SkSecretKey.fromHex(s).tryGet()
+proc parse*(_: type PrivateKey, s: string): Option[PrivateKey] =
+  SkSecretKey.fromHex(s).toOption()
 
 proc sign(key: PrivateKey, data: openArray[byte]): Signature =
   let hash = keccak256.digest(data).data
@@ -42,7 +47,10 @@ proc `$`*(signature: Signature): string =
   bytes[64] += 27
   bytes.toHex()
 
-proc parse*(_: type Signature, s: string): Signature =
-  var bytes = array[65, byte].fromHex(s)
-  bytes[64] -= 27
-  SkRecoverableSignature.fromRaw(bytes).tryGet()
+proc parse*(_: type Signature, s: string): Option[Signature] =
+  try:
+    var bytes = array[65, byte].fromHex(s)
+    bytes[64] = bytes[64] - 27
+    SkRecoverableSignature.fromRaw(bytes).toOption()
+  except ValueError:
+    Signature.none

nitro/state.nim

@@ -27,6 +27,8 @@ type
     outcome*: seq[byte]
     appdata*: seq[byte]
 
+{.push raises:[].}
+
 proc fixedPart*(state: State): FixedPart =
   FixedPart(
     chainId: state.channel.chainId,

nitro/types.nim

@@ -1,17 +1,24 @@
 import std/math
+import std/options
 import pkg/stint
 import pkg/stew/byteutils
 
 export stint
+export options
 
 type
   UInt48* = range[0'u64..2'u64^48-1]
   EthAddress* = distinct array[20, byte]
 
+{.push raises:[].}
+
 proc toArray*(address: EthAddress): array[20, byte] =
   array[20, byte](address)
 
-proc fromHex*(_: type EthAddress, hex: string): EthAddress =
-  EthAddress(array[20, byte].fromHex(hex))
+proc fromHex*(_: type EthAddress, hex: string): Option[EthAddress] =
+  try:
+    EthAddress(array[20, byte].fromHex(hex)).some
+  except ValueError:
+    EthAddress.none
 
 proc `==`*(a, b: EthAddress): bool {.borrow.}

tests/nitro/testChannel.nim

@@ -25,7 +25,7 @@ suite "channel":
       chainId: 9001.u256,
       nonce: 1,
       participants: @[
-        EthAddress.fromHex("24b905Dcc8A11C0FE57C2592f3D25f0447402C10")
+        EthAddress.fromHex("24b905Dcc8A11C0FE57C2592f3D25f0447402C10").get()
       ]
     )
     let expected = array[32, byte].fromHex(

tests/nitro/testOutcome.nim

@@ -94,7 +94,7 @@ suite "outcome":
         kind: allocationType,
         assetHolder: EthAddress.fromHex(
           "1E90B49563da16D2537CA1Ddd9b1285279103D93"
-        ),
+        ).get(),
         allocation: Allocation(@[
           AllocationItem(
             destination: array[32, byte].fromHex(
@@ -108,7 +108,7 @@ suite "outcome":
         kind: guaranteeType,
         assetHolder: EthAddress.fromHex(
           "1E90B49563da16D2537CA1Ddd9b1285279103D93"
-        ),
+        ).get(),
         guarantee: Guarantee(
           targetChannelId: array[32, byte].fromHex(
             "cac1bb71f0a97c8ac94ca9546b43178a9ad254c7b757ac07433aa6df35cd8089"

tests/nitro/testSignature.nim

@@ -26,7 +26,7 @@ suite "signature":
         chainId: 0x1.u256,
         nonce: 1,
         participants: @[
-          EthAddress.fromHex("0x8a64E10FF40Bc9C90EA5750313dB5e036495c10E")
+          EthAddress.fromHex("0x8a64E10FF40Bc9C90EA5750313dB5e036495c10E").get()
         ]
       ),
       outcome: Outcome(@[]),
@@ -38,10 +38,10 @@ suite "signature":
     )
     let seckey = PrivateKey.parse(
       "41b0f5f91967dded8af487277874f95116094cc6004ac2b2169b5b6a87608f3e"
-    )
+    ).get()
     let expected = Signature.parse(
       "9b966cf0065586d59c8b9eb475ac763c96ad8316b81061238f32968a631f9e21" &
       "251363c193c78c89b3eb2fec23f0ea5c3c72acff7d1f27430cfb84b9da9831fb" &
       "1c"
-    )
+    ).get()
     check seckey.sign(state) == expected

tests/nitro/testState.nim

@@ -55,7 +55,7 @@ suite "state":
         chainId: 0x1.u256,
         nonce: 1,
         participants: @[
-          EthAddress.fromHex("DBE821484648c73C1996Da25f2355342B9803eBD")
+          EthAddress.fromHex("DBE821484648c73C1996Da25f2355342B9803eBD").get()
         ]
       ),
       outcome: Outcome(@[]),