Make get_custody_columns return sorted values and add get_custody_columns tests

specs/_features/eip7594/das-core.md

@@ -8,6 +8,8 @@
 <!-- START doctoc generated TOC please keep comment here to allow auto update -->
 <!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
 
+- [Constants](#constants)
+  - [Misc](#misc)
 - [Custom types](#custom-types)
 - [Configuration](#configuration)
   - [Data size](#data-size)
@@ -39,6 +41,16 @@
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
 <!-- /TOC -->
 
+## Constants
+
+The following values are (non-configurable) constants used throughout the specification.
+
+### Misc
+
+| Name | Value |
+| - | - |
+| `UINT256_MAX` | `uint256(2**256 - 1)` |
+
 ## Custom types
 
 We define the following Python custom types for type hinting and readability:
@@ -95,8 +107,11 @@ def get_custody_columns(node_id: NodeID, custody_subnet_count: uint64) -> Sequen
     subnet_ids = []
     i = 0
     while len(subnet_ids) < custody_subnet_count:
+        if node_id == UINT256_MAX:
+            node_id = 0
+
         subnet_id = (
-            bytes_to_uint64(hash(uint_to_bytes(uint64(node_id + i)))[0:8])
+            bytes_to_uint64(hash(uint_to_bytes(uint256(node_id + i)))[0:8])
             % DATA_COLUMN_SIDECAR_SUBNET_COUNT
         )
         if subnet_id not in subnet_ids:
@@ -105,11 +120,11 @@ def get_custody_columns(node_id: NodeID, custody_subnet_count: uint64) -> Sequen
     assert len(subnet_ids) == len(set(subnet_ids))
 
     columns_per_subnet = NUMBER_OF_COLUMNS // DATA_COLUMN_SIDECAR_SUBNET_COUNT
-    return [
+    return sorted([
         ColumnIndex(DATA_COLUMN_SIDECAR_SUBNET_COUNT * i + subnet_id)
         for i in range(columns_per_subnet)
         for subnet_id in subnet_ids
-    ]
+    ])
 ```
 
 #### `compute_extended_matrix`

tests/core/pyspec/eth2spec/test/eip7594/networking/test_get_custody_columns.py

@@ -0,0 +1,89 @@
+import random
+
+from eth2spec.test.context import (
+    single_phase,
+    spec_test,
+    with_eip7594_and_later,
+)
+
+
+def _run_get_custody_columns(spec, rng, node_id=None, custody_subnet_count=None):
+    if node_id is None:
+        node_id = rng.randint(0, 2**256 - 1)
+
+    if custody_subnet_count is None:
+        custody_subnet_count = rng.randint(0, spec.config.DATA_COLUMN_SIDECAR_SUBNET_COUNT)
+
+    result = spec.get_custody_columns(node_id, custody_subnet_count)
+    yield 'node_id', 'meta', node_id
+    yield 'custody_subnet_count', 'meta', custody_subnet_count
+
+    assert len(result) == len(set(result))
+    assert len(result) == (
+        custody_subnet_count * spec.config.NUMBER_OF_COLUMNS // spec.config.DATA_COLUMN_SIDECAR_SUBNET_COUNT
+    )
+    assert all(i < spec.config.NUMBER_OF_COLUMNS for i in result)
+    python_list_result = [int(i) for i in result]
+
+    yield 'result', 'meta', python_list_result
+
+
+@with_eip7594_and_later
+@spec_test
+@single_phase
+def test_get_custody_columns__min_node_id_min_custody_subnet_count(spec):
+    rng = random.Random(1111)
+    yield from _run_get_custody_columns(spec, rng, node_id=0, custody_subnet_count=0)
+
+
+@with_eip7594_and_later
+@spec_test
+@single_phase
+def test_get_custody_columns__min_node_id_max_custody_subnet_count(spec):
+    rng = random.Random(1111)
+    yield from _run_get_custody_columns(
+        spec, rng, node_id=0,
+        custody_subnet_count=spec.config.DATA_COLUMN_SIDECAR_SUBNET_COUNT)
+
+
+@with_eip7594_and_later
+@spec_test
+@single_phase
+def test_get_custody_columns__max_node_id_min_custody_subnet_count(spec):
+    rng = random.Random(1111)
+    yield from _run_get_custody_columns(spec, rng, node_id=2**256 - 1, custody_subnet_count=0)
+
+
+@with_eip7594_and_later
+@spec_test
+@single_phase
+def test_get_custody_columns__max_node_id_max_custody_subnet_count(spec):
+    rng = random.Random(1111)
+    yield from _run_get_custody_columns(
+        spec, rng, node_id=2**256 - 1,
+        custody_subnet_count=spec.config.DATA_COLUMN_SIDECAR_SUBNET_COUNT,
+    )
+
+
+@with_eip7594_and_later
+@spec_test
+@single_phase
+def test_get_custody_columns__1(spec):
+    rng = random.Random(1111)
+    yield from _run_get_custody_columns(spec, rng)
+
+
+@with_eip7594_and_later
+@spec_test
+@single_phase
+def test_get_custody_columns__2(spec):
+    rng = random.Random(2222)
+    yield from _run_get_custody_columns(spec, rng)
+
+
+@with_eip7594_and_later
+@spec_test
+@single_phase
+def test_get_custody_columns__3(spec):
+    rng = random.Random(3333)
+    yield from _run_get_custody_columns(spec, rng)

tests/formats/networking/README.md

@@ -0,0 +1,6 @@
+# Networking tests
+
+The aim of the networking tests is to set a base-line on what really needs to pass, i.e. the essentials.
+
+Handlers:
+- [`get_custody_columns`](./get_custody_columns.md): `get_custody_columns` helper tests

tests/formats/networking/get_custody_columns.md

@@ -0,0 +1,14 @@
+# `get_custody_columns` tests
+
+`get_custody_columns` tests provide sanity check of the correctness of `get_custody_columns` helper.
+
+## Test case format
+
+### `meta.yaml`
+
+```yaml
+description: string            -- optional: description of test case, purely for debugging purposes.
+node_id: int                   -- argument: the NodeId input.
+custody_subnet_count: int      -- argument: the count of custody subnets.
+result: list of int            -- output: the list of resulting column indices.
+```

tests/generators/networking/README.md

@@ -0,0 +1,5 @@
+# Networking tests
+
+The purpose of this test-generator is to provide test-vectors for validating the correct implementation of the networking protocol.
+
+Test-format documentation can be found [here](../../formats/networking/README.md).

tests/generators/networking/main.py

@@ -0,0 +1,14 @@
+
+from eth2spec.test.helpers.constants import EIP7594
+from eth2spec.gen_helpers.gen_from_tests.gen import run_state_test_generators
+
+
+if __name__ == "__main__":
+    eip7594_mods = {key: 'eth2spec.test.eip7594.networking.test_' + key for key in [
+        'get_custody_columns',
+    ]}
+    all_mods = {
+        EIP7594: eip7594_mods
+    }
+
+    run_state_test_generators(runner_name="networking", all_mods=all_mods)

tests/generators/networking/requirements.txt

@@ -0,0 +1,2 @@
+pytest>=4.4
+../../../[generator]