From 46e266c70a77a9ecebe6829aefc62218fb4ee52e Mon Sep 17 00:00:00 2001
From: Jason Carver <ut96caarrs@snkmail.com>
Date: Wed, 25 Sep 2024 20:27:42 -0700
Subject: [PATCH] Bitfield::with_capacity fix OutOfBounds i field, plus doc
 typo fix (#33)

* docs: Bitfield::with_capacity returns Result not Option

* fix: Bitfield::with_capacity OutOfBounds field bug

It was returning the max length twice, and now returns the actual length
and maximum length.
---
 ssz/src/bitfield.rs | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/ssz/src/bitfield.rs b/ssz/src/bitfield.rs
index 7bac6bd..15c9eba 100644
--- a/ssz/src/bitfield.rs
+++ b/ssz/src/bitfield.rs
@@ -125,7 +125,7 @@ impl<N: Unsigned + Clone> Bitfield<Variable<N>> {
     ///
     /// All bits are initialized to `false`.
     ///
-    /// Returns `None` if `num_bits > N`.
+    /// Returns `Err` if `num_bits > N`.
     pub fn with_capacity(num_bits: usize) -> Result<Self, Error> {
         if num_bits <= N::to_usize() {
             Ok(Self {
@@ -135,7 +135,7 @@ impl<N: Unsigned + Clone> Bitfield<Variable<N>> {
             })
         } else {
             Err(Error::OutOfBounds {
-                i: Self::max_len(),
+                i: num_bits,
                 len: Self::max_len(),
             })
         }
@@ -1429,4 +1429,10 @@ mod bitlist {
         // Can't extend a BitList to a smaller BitList
         resized_bit_list.resize::<typenum::U16>().unwrap_err();
     }
+
+    #[test]
+    fn over_capacity_err() {
+        let e = BitList8::with_capacity(9).expect_err("over-sized bit list");
+        assert_eq!(e, Error::OutOfBounds { i: 9, len: 8 });
+    }
 }