Implement shuffling test (pending typedesc and shuffling algo fix)

tests/official/fixtures_utils.nim

@@ -12,14 +12,15 @@ export nimcrypto.toHex
 type
   # TODO: use ref object to avoid allocating
   #       so much on the stack - pending https://github.com/status-im/nim-json-serialization/issues/3
-  StateTest* = object
+  StateTests* = object
     title*: string
     summary*: string
     test_suite*: string
     fork*: string
-    test_cases*: seq[TestCase]
+    test_cases*: seq[StateTestCase]
   
   TestConstants* = object
+    # TODO - 0.5.1 constants
     SHARD_COUNT*: int
     TARGET_COMMITTEE_SIZE*: int
     MAX_BALANCE_CHURN_QUOTIENT*: int
@@ -66,13 +67,30 @@ type
     DOMAIN_VOLUNTARY_EXIT*: SignatureDomain
     DOMAIN_TRANSFER*: SignatureDomain
 
-  TestCase* = object
+  StateTestCase* = object
     name*: string
     config*: TestConstants
     verify_signatures*: bool
     initial_state*: BeaconState
     blocks*: seq[BeaconBlock]
     expected_state*: BeaconState
+
+  ShufflingTests* = object
+    title*: string
+    summary*: string
+    forks_timeline*: string
+    forks*: seq[string]
+    config*: string
+    runner*: string
+    handler*: string
+    test_cases*: seq[ShufflingTestCase]
+
+  ShufflingTestCase* = object
+    seed*: Eth2Digest
+    count*: uint64
+    shuffled*: seq[ValidatorIndex]
+
+  Tests* = StateTests or ShufflingTests
   
 # #######################
 # Default init
@@ -89,9 +107,27 @@ proc readValue*[N: static int](r: var JsonReader, a: var array[N, byte]) {.inlin
   #       if so export that to nim-eth
   hexToByteArray(r.readValue(string), a)
 
-proc parseStateTests*(jsonPath: string): StateTest =
+proc readValue*(r: var JsonReader, a: var ValidatorIndex) {.inline.} =
+  a = r.readValue(uint32)
+
+# TODO: cannot pass a typedesc
+# proc parseTests*(jsonPath: string, T: typedesc[Tests]): T =
+#   # TODO: due to generic early symbol resolution
+#   #       we cannot use a generic proc
+#   #       Otherwise we get:
+#   #       "Error: undeclared identifier: 'ReaderType'"
+#   #       Templates, even untyped don't work
+#   try:
+#     result = Json.loadFile(jsonPath, T)
+#   except SerializationError as err:
+#     writeStackTrace()
+#     stderr.write "Json load issue for file \"", jsonPath, "\"\n"
+#     stderr.write err.formatMsg(jsonPath), "\n"
+#     quit 1
+
+proc parseTests*(jsonPath: string): ShufflingTests =
   try:
-    result = Json.loadFile(jsonPath, StateTest)
+    result = Json.loadFile(jsonPath, ShufflingTests)
   except SerializationError as err:
     writeStackTrace()
     stderr.write "Json load issue for file \"", jsonPath, "\"\n"

tests/official/test_fixture_shuffling.nim

@@ -0,0 +1,30 @@
+# beacon_chain
+# Copyright (c) 2018 Status Research & Development GmbH
+# Licensed and distributed under either of
+#   * MIT license (license terms in the root directory or at http://opensource.org/licenses/MIT).
+#   * Apache v2 license (license terms in the root directory or at 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.
+
+import
+  # Standard libs
+  ospaths, strutils, json, unittest,
+  # Third parties
+
+  # Beacon chain internals
+  ../../beacon_chain/spec/validator,
+  # Test utilities
+  ./fixtures_utils
+
+const TestFolder = currentSourcePath.rsplit(DirSep, 1)[0]
+const TestsPath = "fixtures" / "json_tests" / "shuffling" / "core" / "shuffling_full.json"
+
+var shufflingTests: ShufflingTests
+
+suite "Official - Shuffling tests":
+  test "Parsing the official shuffling tests":
+    shufflingTests = parseTests(TestFolder / TestsPath)
+
+  test "Shuffling a sequence of N validators":
+    for t in shufflingTests.test_cases:
+      let implResult = get_shuffled_seq(t.seed, t.count)
+      check: implResult == t.shuffled

tests/official/test_fixture_state.nim

@@ -14,17 +14,17 @@ import
   ../../beacon_chain/spec/[datatypes, crypto, digest, beaconstate],
   ../../beacon_chain/[ssz, state_transition],
   # Test utilities
-  ./state_test_utils
+  ./fixtures_utils
 
 const TestFolder = currentSourcePath.rsplit(DirSep, 1)[0]
 const TestsPath = "fixtures" / "json_tests" / "state" / "sanity-check_default-config_100-vals.json"
 
 
-var stateTests: StateTest
+var stateTests: StateTests
 suite "Official - State tests": # Initializing a beacon state from the deposits
   # Source: https://github.com/ethereum/eth2.0-specs/blob/2baa242ac004b0475604c4c4ef4315e14f56c5c7/tests/phase0/test_sanity.py#L55-L460
   test "Parsing the official state tests into Nimbus beacon types":
-    stateTests = parseStateTests(TestFolder / TestsPath)
+    stateTests = parseTests(TestFolder / TestsPath, StateTests) # TODO pending typedesc fix in fixture_utils.nim
     doAssert $stateTests.test_cases[0].name == "test_empty_block_transition"
   
   test "[For information - Non-blocking] Block root signing":