From 035e124a14a90fcc6b8fb617455a2ff1fcf8f1ce Mon Sep 17 00:00:00 2001
From: Paul Hauner <paul@paulhauner.com>
Date: Wed, 15 May 2019 11:45:50 +1000
Subject: [PATCH] Remove serde de-ser constraint from `Cases`

---
 tests/ef_tests/src/cases.rs | 4 ++--
 tests/ef_tests/src/doc.rs   | 4 +++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/tests/ef_tests/src/cases.rs b/tests/ef_tests/src/cases.rs
index bfc2900c71..5bb1bdc2fc 100644
--- a/tests/ef_tests/src/cases.rs
+++ b/tests/ef_tests/src/cases.rs
@@ -1,6 +1,5 @@
 use super::*;
 use crate::yaml_decode::*;
-use serde_derive::Deserialize;
 use yaml_rust::YamlLoader;
 
 mod ssz_generic;
@@ -9,7 +8,7 @@ mod ssz_static;
 pub use ssz_generic::*;
 pub use ssz_static::*;
 
-#[derive(Debug, Deserialize)]
+#[derive(Debug)]
 pub struct Cases<T> {
     pub test_cases: Vec<T>,
 }
@@ -23,6 +22,7 @@ impl<T: YamlDecode> YamlDecode for Cases<T> {
 
         let mut i = 0;
         loop {
+            // `is_badvalue` indicates when we have reached the end of the YAML list.
             if doc[i].is_badvalue() {
                 break;
             } else {
diff --git a/tests/ef_tests/src/doc.rs b/tests/ef_tests/src/doc.rs
index e67f7c713d..0182e74795 100644
--- a/tests/ef_tests/src/doc.rs
+++ b/tests/ef_tests/src/doc.rs
@@ -59,10 +59,12 @@ impl Doc {
 
 pub fn run_test<T, E: EthSpec>(test_doc_yaml: &String) -> Vec<CaseResult>
 where
-    Cases<T>: EfTest + serde::de::DeserializeOwned + YamlDecode,
+    Cases<T>: EfTest + YamlDecode,
 {
+    // Extract only the "test_cases" YAML as a stand-alone string.
     let test_cases_yaml = extract_yaml_by_key(test_doc_yaml, "test_cases");
 
+    // Pass only the "test_cases" YAML string to `yaml_decode`.
     let test_cases: Cases<T> = Cases::yaml_decode(&test_cases_yaml.to_string()).unwrap();
 
     test_cases.test_results::<E>()