From d28fed951ff4b30bcc4474c5e876abdc547e643b Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 07:42:22 -0800
Subject: [PATCH 01/16] Initial impl and test of encode_unsigned_1

---
 native_implemented/otp/src/erlang.rs          |  1 +
 .../otp/src/erlang/encode_unsigned_1.rs       | 47 +++++++++++++++++++
 .../otp/src/erlang/encode_unsigned_1/test.rs  | 32 +++++++++++++
 3 files changed, 80 insertions(+)
 create mode 100644 native_implemented/otp/src/erlang/encode_unsigned_1.rs
 create mode 100644 native_implemented/otp/src/erlang/encode_unsigned_1/test.rs

diff --git a/native_implemented/otp/src/erlang.rs b/native_implemented/otp/src/erlang.rs
index 352421b10..8793ebadc 100644
--- a/native_implemented/otp/src/erlang.rs
+++ b/native_implemented/otp/src/erlang.rs
@@ -49,6 +49,7 @@ pub mod display_1;
 pub mod div_2;
 pub mod divide_2;
 pub mod element_2;
+pub mod encode_unsigned_1;
 pub mod erase_0;
 pub mod erase_1;
 pub mod error_1;
diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1.rs b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
new file mode 100644
index 000000000..2cf8a7a7b
--- /dev/null
+++ b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
@@ -0,0 +1,47 @@
+#[cfg(all(not(target_arch = "wasm32"), test))]
+mod test;
+
+use liblumen_alloc::erts::exception;
+use liblumen_alloc::erts::process::Process;
+use liblumen_alloc::erts::term::prelude::*;
+use crate::runtime::context::term_is_not_integer;
+use anyhow::*;
+
+/// Returns the smallest possible representation in a binary digit representation for the given big endian unsigned integer.
+#[native_implemented::function(erlang:encode_unsigned/1)]
+pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
+    match term.decode().unwrap() {
+        TypedTerm::SmallInteger(small_integer) => {
+            let mut bytes: Vec<u8> = small_integer
+                .to_le_bytes()
+                .iter()
+                .filter_map(|&b| match b {
+                    0 => None,
+                    b => Some(b)
+                })
+                .collect();
+
+            bytes.reverse();
+
+            Ok(process.binary_from_bytes(&bytes))
+        },
+        TypedTerm::BigInteger(big_integer) => {
+            let bytes: Vec<u8> = big_integer
+                .to_signed_bytes_be()
+                .iter()
+                .filter_map(|&b| match b {
+                    0 => None,
+                    b => Some(b)
+                })
+                .collect();
+
+            Ok(process.binary_from_bytes(&bytes))
+        },
+        _ => Err(TypeError)
+            .context(term_is_not_integer(
+                "encoded_unsigned",
+                term
+            ))
+            .map_err(From::from),
+    }
+}
diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs b/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
new file mode 100644
index 000000000..82be24f90
--- /dev/null
+++ b/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
@@ -0,0 +1,32 @@
+use crate::erlang::encode_unsigned_1::result;
+use crate::test::with_process;
+use liblumen_alloc::erts::term::prelude::*;
+use num_bigint::BigInt;
+
+// 1> binary:encode_unsigned(11111111).
+// <<169,138,199>>
+#[test]
+fn otp_doctest() {
+    with_process(|process| {
+        assert_eq!(
+            result(process, process.integer(11111111)),
+            Ok(process.binary_from_bytes(&[169,138,199]))
+        )
+    });
+}
+
+#[test]
+fn smallest_big_int() {
+    let largest_small_int_as_big_int: BigInt = SmallInteger::MAX_VALUE.into();
+    let smallest_big_int: BigInt = largest_small_int_as_big_int + 1;
+
+    // 1> binary:encode_unsigned(70368744177664).
+    // <<64,0,0,0,0,0>>
+
+    with_process(|process| {
+        assert_eq!(
+            result(process, process.integer(smallest_big_int)),
+            Ok(process.binary_from_bytes(&[64]))
+        )
+    });
+}
\ No newline at end of file

From ed869b0fe7902abed7921750be7743b2217e6ee3 Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 08:21:37 -0800
Subject: [PATCH 02/16] update handling for non-integer arg and negative
 proptest

---
 .../otp/src/erlang/encode_unsigned_1.rs       |  2 +-
 .../otp/src/erlang/encode_unsigned_1/test.rs  | 21 +++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1.rs b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
index 2cf8a7a7b..6d698f1ef 100644
--- a/native_implemented/otp/src/erlang/encode_unsigned_1.rs
+++ b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
@@ -37,7 +37,7 @@ pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
 
             Ok(process.binary_from_bytes(&bytes))
         },
-        _ => Err(TypeError)
+        _ => Err(TryIntoIntegerError::Type)
             .context(term_is_not_integer(
                 "encoded_unsigned",
                 term
diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs b/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
index 82be24f90..7f28031d8 100644
--- a/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
+++ b/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
@@ -2,6 +2,8 @@ use crate::erlang::encode_unsigned_1::result;
 use crate::test::with_process;
 use liblumen_alloc::erts::term::prelude::*;
 use num_bigint::BigInt;
+use crate::test::*;
+use proptest::strategy::Just;
 
 // 1> binary:encode_unsigned(11111111).
 // <<169,138,199>>
@@ -29,4 +31,23 @@ fn smallest_big_int() {
             Ok(process.binary_from_bytes(&[64]))
         )
     });
+}
+
+#[test]
+fn not_integer() {
+    run!(
+        |arc_process| {
+            (
+                Just(arc_process.clone()),
+                strategy::term::is_not_integer(arc_process.clone())
+            )
+        },
+        |(arc_process, non_int)| {
+            prop_assert_badarg!(
+                result(&arc_process, non_int),
+                "invalid integer conversion"
+            );
+            Ok(())
+        },
+    );
 }
\ No newline at end of file

From b42e063e2188b8c41dcf23c1535c8225a6607870 Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 08:44:52 -0800
Subject: [PATCH 03/16] handle negative integers as bardarg and add proptests

---
 .../otp/src/erlang/encode_unsigned_1.rs       | 21 ++++++++++++++++++-
 .../otp/src/erlang/encode_unsigned_1/test.rs  | 19 +++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1.rs b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
index 6d698f1ef..96a50771f 100644
--- a/native_implemented/otp/src/erlang/encode_unsigned_1.rs
+++ b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
@@ -4,14 +4,24 @@ mod test;
 use liblumen_alloc::erts::exception;
 use liblumen_alloc::erts::process::Process;
 use liblumen_alloc::erts::term::prelude::*;
-use crate::runtime::context::term_is_not_integer;
+use crate::runtime::context::{term_is_not_integer, term_is_not_non_negative_integer};
 use anyhow::*;
+use num_bigint::Sign;
 
 /// Returns the smallest possible representation in a binary digit representation for the given big endian unsigned integer.
 #[native_implemented::function(erlang:encode_unsigned/1)]
 pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
     match term.decode().unwrap() {
         TypedTerm::SmallInteger(small_integer) => {
+            let signed: isize = small_integer.into();
+            if signed < 0 {
+                return Err(TryIntoIntegerError::Type)
+                    .context(term_is_not_non_negative_integer(
+                        "encoded_unsigned",
+                        term
+                    ))
+                    .map_err(From::from);
+            }
             let mut bytes: Vec<u8> = small_integer
                 .to_le_bytes()
                 .iter()
@@ -26,6 +36,15 @@ pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
             Ok(process.binary_from_bytes(&bytes))
         },
         TypedTerm::BigInteger(big_integer) => {
+            if Sign::Minus == big_integer.sign() {
+                return Err(TryIntoIntegerError::Type)
+                    .context(term_is_not_non_negative_integer(
+                        "encoded_unsigned",
+                        term
+                    ))
+                    .map_err(From::from);
+            }
+
             let bytes: Vec<u8> = big_integer
                 .to_signed_bytes_be()
                 .iter()
diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs b/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
index 7f28031d8..4b3663735 100644
--- a/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
+++ b/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
@@ -33,6 +33,25 @@ fn smallest_big_int() {
     });
 }
 
+#[test]
+fn negative_integer() {
+    run!(
+        |arc_process| {
+            (
+                Just(arc_process.clone()),
+                strategy::term::integer::negative(arc_process.clone())
+            )
+        },
+        |(arc_process, non_int)| {
+            prop_assert_badarg!(
+                result(&arc_process, non_int),
+                "invalid integer conversion"
+            );
+            Ok(())
+        },
+    );
+}
+
 #[test]
 fn not_integer() {
     run!(

From d70d7aa72a7929b5da7194190bfc204fad61b46d Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 08:46:59 -0800
Subject: [PATCH 04/16] auto-formatting

---
 .../otp/src/erlang/encode_unsigned_1.rs       | 30 +++++++------------
 .../otp/src/erlang/encode_unsigned_1/test.rs  | 20 +++++--------
 2 files changed, 18 insertions(+), 32 deletions(-)

diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1.rs b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
index 96a50771f..a9ae60a23 100644
--- a/native_implemented/otp/src/erlang/encode_unsigned_1.rs
+++ b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
@@ -1,14 +1,15 @@
 #[cfg(all(not(target_arch = "wasm32"), test))]
 mod test;
 
+use crate::runtime::context::{term_is_not_integer, term_is_not_non_negative_integer};
+use anyhow::*;
 use liblumen_alloc::erts::exception;
 use liblumen_alloc::erts::process::Process;
 use liblumen_alloc::erts::term::prelude::*;
-use crate::runtime::context::{term_is_not_integer, term_is_not_non_negative_integer};
-use anyhow::*;
 use num_bigint::Sign;
 
-/// Returns the smallest possible representation in a binary digit representation for the given big endian unsigned integer.
+/// Returns the smallest possible representation in a binary digit representation for the given big
+/// endian unsigned integer.
 #[native_implemented::function(erlang:encode_unsigned/1)]
 pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
     match term.decode().unwrap() {
@@ -16,10 +17,7 @@ pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
             let signed: isize = small_integer.into();
             if signed < 0 {
                 return Err(TryIntoIntegerError::Type)
-                    .context(term_is_not_non_negative_integer(
-                        "encoded_unsigned",
-                        term
-                    ))
+                    .context(term_is_not_non_negative_integer("encoded_unsigned", term))
                     .map_err(From::from);
             }
             let mut bytes: Vec<u8> = small_integer
@@ -27,21 +25,18 @@ pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
                 .iter()
                 .filter_map(|&b| match b {
                     0 => None,
-                    b => Some(b)
+                    b => Some(b),
                 })
                 .collect();
 
             bytes.reverse();
 
             Ok(process.binary_from_bytes(&bytes))
-        },
+        }
         TypedTerm::BigInteger(big_integer) => {
             if Sign::Minus == big_integer.sign() {
                 return Err(TryIntoIntegerError::Type)
-                    .context(term_is_not_non_negative_integer(
-                        "encoded_unsigned",
-                        term
-                    ))
+                    .context(term_is_not_non_negative_integer("encoded_unsigned", term))
                     .map_err(From::from);
             }
 
@@ -50,17 +45,14 @@ pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
                 .iter()
                 .filter_map(|&b| match b {
                     0 => None,
-                    b => Some(b)
+                    b => Some(b),
                 })
                 .collect();
 
             Ok(process.binary_from_bytes(&bytes))
-        },
+        }
         _ => Err(TryIntoIntegerError::Type)
-            .context(term_is_not_integer(
-                "encoded_unsigned",
-                term
-            ))
+            .context(term_is_not_integer("encoded_unsigned", term))
             .map_err(From::from),
     }
 }
diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs b/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
index 4b3663735..1663eb09d 100644
--- a/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
+++ b/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
@@ -1,8 +1,8 @@
 use crate::erlang::encode_unsigned_1::result;
 use crate::test::with_process;
+use crate::test::*;
 use liblumen_alloc::erts::term::prelude::*;
 use num_bigint::BigInt;
-use crate::test::*;
 use proptest::strategy::Just;
 
 // 1> binary:encode_unsigned(11111111).
@@ -12,7 +12,7 @@ fn otp_doctest() {
     with_process(|process| {
         assert_eq!(
             result(process, process.integer(11111111)),
-            Ok(process.binary_from_bytes(&[169,138,199]))
+            Ok(process.binary_from_bytes(&[169, 138, 199]))
         )
     });
 }
@@ -39,14 +39,11 @@ fn negative_integer() {
         |arc_process| {
             (
                 Just(arc_process.clone()),
-                strategy::term::integer::negative(arc_process.clone())
+                strategy::term::integer::negative(arc_process.clone()),
             )
         },
         |(arc_process, non_int)| {
-            prop_assert_badarg!(
-                result(&arc_process, non_int),
-                "invalid integer conversion"
-            );
+            prop_assert_badarg!(result(&arc_process, non_int), "invalid integer conversion");
             Ok(())
         },
     );
@@ -58,15 +55,12 @@ fn not_integer() {
         |arc_process| {
             (
                 Just(arc_process.clone()),
-                strategy::term::is_not_integer(arc_process.clone())
+                strategy::term::is_not_integer(arc_process.clone()),
             )
         },
         |(arc_process, non_int)| {
-            prop_assert_badarg!(
-                result(&arc_process, non_int),
-                "invalid integer conversion"
-            );
+            prop_assert_badarg!(result(&arc_process, non_int), "invalid integer conversion");
             Ok(())
         },
     );
-}
\ No newline at end of file
+}

From 665cde96051d1a2227afeb3d51bcb9fcbf424485 Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 09:29:11 -0800
Subject: [PATCH 05/16] Fix handling of leading/trailing zeros

---
 .../otp/src/erlang/encode_unsigned_1.rs       | 28 +++--------
 .../otp/src/erlang/encode_unsigned_1/test.rs  | 47 ++++++++++++++++++-
 2 files changed, 53 insertions(+), 22 deletions(-)

diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1.rs b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
index a9ae60a23..38d8d0e04 100644
--- a/native_implemented/otp/src/erlang/encode_unsigned_1.rs
+++ b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
@@ -20,18 +20,10 @@ pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
                     .context(term_is_not_non_negative_integer("encoded_unsigned", term))
                     .map_err(From::from);
             }
-            let mut bytes: Vec<u8> = small_integer
-                .to_le_bytes()
-                .iter()
-                .filter_map(|&b| match b {
-                    0 => None,
-                    b => Some(b),
-                })
-                .collect();
-
+            let mut bytes: Vec<u8> = small_integer.to_le_bytes();
             bytes.reverse();
-
-            Ok(process.binary_from_bytes(&bytes))
+            let first_nonzero_index = bytes.iter().position(|&b| b != 0).unwrap_or(0);
+            Ok(process.binary_from_bytes(&bytes[first_nonzero_index..]))
         }
         TypedTerm::BigInteger(big_integer) => {
             if Sign::Minus == big_integer.sign() {
@@ -40,16 +32,10 @@ pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
                     .map_err(From::from);
             }
 
-            let bytes: Vec<u8> = big_integer
-                .to_signed_bytes_be()
-                .iter()
-                .filter_map(|&b| match b {
-                    0 => None,
-                    b => Some(b),
-                })
-                .collect();
-
-            Ok(process.binary_from_bytes(&bytes))
+            let bytes: Vec<u8> = big_integer.to_signed_bytes_be();
+            let first_nonzero_index_from_left = bytes.iter().position(|&b| b != 0).unwrap_or(0);
+            let first_nonzero_index_from_right = bytes.iter().rposition(|&b| b != 0).unwrap_or(0);
+            Ok(process.binary_from_bytes(&bytes[first_nonzero_index_from_left..(first_nonzero_index_from_right + 1)]))
         }
         _ => Err(TryIntoIntegerError::Type)
             .context(term_is_not_integer("encoded_unsigned", term))
diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs b/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
index 1663eb09d..a9b65fde8 100644
--- a/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
+++ b/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
@@ -2,7 +2,7 @@ use crate::erlang::encode_unsigned_1::result;
 use crate::test::with_process;
 use crate::test::*;
 use liblumen_alloc::erts::term::prelude::*;
-use num_bigint::BigInt;
+use num_bigint::{BigInt, ToBigInt};
 use proptest::strategy::Just;
 
 // 1> binary:encode_unsigned(11111111).
@@ -33,6 +33,51 @@ fn smallest_big_int() {
     });
 }
 
+#[test]
+fn big_int_with_middle_zeros() {
+    let largest_small_int_as_big_int: BigInt = SmallInteger::MAX_VALUE.into();
+    let big_int_with_middle_zeros: BigInt = largest_small_int_as_big_int + 2;
+
+    // 1> binary:encode_unsigned(70368744177665).
+    // <<64,0,0,0,0,1>>
+    with_process(|process| {
+        assert_eq!(
+            result(process, process.integer(big_int_with_middle_zeros)),
+            Ok(process.binary_from_bytes(&[64, 0, 0, 0, 0, 1]))
+        )
+    });
+}
+
+#[test]
+fn small_int_with_middle_zeros() {
+    // 1> binary:encode_unsigned(11075783).
+    // <<169,0,199>>
+    let largest_small_int_as_big_int: BigInt = SmallInteger::MAX_VALUE.into();
+    assert!(11075783.to_bigint().unwrap() < largest_small_int_as_big_int);
+
+    with_process(|process| {
+        assert_eq!(
+            result(process, process.integer(11075783)),
+            Ok(process.binary_from_bytes(&[169, 0, 199]))
+        )
+    });
+}
+
+#[test]
+fn small_int_with_trailing_zeros() {
+    // 1> binary:encode_unsigned(16777216).
+    // <<1,0,0,0>>
+    let largest_small_int_as_big_int: BigInt = SmallInteger::MAX_VALUE.into();
+    assert!(16777216.to_bigint().unwrap() < largest_small_int_as_big_int);
+
+    with_process(|process| {
+        assert_eq!(
+            result(process, process.integer(16777216)),
+            Ok(process.binary_from_bytes(&[1, 0, 0, 0]))
+        )
+    });
+}
+
 #[test]
 fn negative_integer() {
     run!(

From 4b8dfdebf172bacc18950d14089b313f11858c31 Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 09:30:01 -0800
Subject: [PATCH 06/16] auto-formatting

---
 native_implemented/otp/src/erlang/encode_unsigned_1.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1.rs b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
index 38d8d0e04..9431f93a5 100644
--- a/native_implemented/otp/src/erlang/encode_unsigned_1.rs
+++ b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
@@ -35,7 +35,9 @@ pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
             let bytes: Vec<u8> = big_integer.to_signed_bytes_be();
             let first_nonzero_index_from_left = bytes.iter().position(|&b| b != 0).unwrap_or(0);
             let first_nonzero_index_from_right = bytes.iter().rposition(|&b| b != 0).unwrap_or(0);
-            Ok(process.binary_from_bytes(&bytes[first_nonzero_index_from_left..(first_nonzero_index_from_right + 1)]))
+            Ok(process.binary_from_bytes(
+                &bytes[first_nonzero_index_from_left..(first_nonzero_index_from_right + 1)],
+            ))
         }
         _ => Err(TryIntoIntegerError::Type)
             .context(term_is_not_integer("encoded_unsigned", term))

From 1b1abdb086697d3c103fcd3e80b838e6340e7ff9 Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 09:39:03 -0800
Subject: [PATCH 07/16] Fix bug with BigInt with trailing zeros

---
 native_implemented/otp/src/erlang/encode_unsigned_1.rs     | 7 ++-----
 .../otp/src/erlang/encode_unsigned_1/test.rs               | 2 +-
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1.rs b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
index 9431f93a5..4c9608c45 100644
--- a/native_implemented/otp/src/erlang/encode_unsigned_1.rs
+++ b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
@@ -33,11 +33,8 @@ pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
             }
 
             let bytes: Vec<u8> = big_integer.to_signed_bytes_be();
-            let first_nonzero_index_from_left = bytes.iter().position(|&b| b != 0).unwrap_or(0);
-            let first_nonzero_index_from_right = bytes.iter().rposition(|&b| b != 0).unwrap_or(0);
-            Ok(process.binary_from_bytes(
-                &bytes[first_nonzero_index_from_left..(first_nonzero_index_from_right + 1)],
-            ))
+            let first_nonzero_index = bytes.iter().position(|&b| b != 0).unwrap_or(0);
+            Ok(process.binary_from_bytes(&bytes[first_nonzero_index..]))
         }
         _ => Err(TryIntoIntegerError::Type)
             .context(term_is_not_integer("encoded_unsigned", term))
diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs b/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
index a9b65fde8..072c3fe71 100644
--- a/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
+++ b/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
@@ -28,7 +28,7 @@ fn smallest_big_int() {
     with_process(|process| {
         assert_eq!(
             result(process, process.integer(smallest_big_int)),
-            Ok(process.binary_from_bytes(&[64]))
+            Ok(process.binary_from_bytes(&[64, 0, 0, 0, 0, 0]))
         )
     });
 }

From 3576682eb8f84d6f83a3ab00ee1b9ac273eee6dd Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 09:43:37 -0800
Subject: [PATCH 08/16] small refactor

---
 .../otp/src/erlang/encode_unsigned_1.rs              | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1.rs b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
index 4c9608c45..5177c0bf5 100644
--- a/native_implemented/otp/src/erlang/encode_unsigned_1.rs
+++ b/native_implemented/otp/src/erlang/encode_unsigned_1.rs
@@ -22,8 +22,7 @@ pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
             }
             let mut bytes: Vec<u8> = small_integer.to_le_bytes();
             bytes.reverse();
-            let first_nonzero_index = bytes.iter().position(|&b| b != 0).unwrap_or(0);
-            Ok(process.binary_from_bytes(&bytes[first_nonzero_index..]))
+            Ok(process.binary_from_bytes(without_leading_zeros(&bytes)))
         }
         TypedTerm::BigInteger(big_integer) => {
             if Sign::Minus == big_integer.sign() {
@@ -33,11 +32,16 @@ pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
             }
 
             let bytes: Vec<u8> = big_integer.to_signed_bytes_be();
-            let first_nonzero_index = bytes.iter().position(|&b| b != 0).unwrap_or(0);
-            Ok(process.binary_from_bytes(&bytes[first_nonzero_index..]))
+            Ok(process.binary_from_bytes(without_leading_zeros(&bytes)))
         }
         _ => Err(TryIntoIntegerError::Type)
             .context(term_is_not_integer("encoded_unsigned", term))
             .map_err(From::from),
     }
 }
+
+#[inline]
+fn without_leading_zeros(bytes: &Vec<u8>) -> &[u8] {
+    let first_nonzero_index = bytes.iter().position(|&b| b != 0).unwrap_or(0);
+    &bytes[first_nonzero_index..]
+}

From 184951d81621a7004b5190b99bdcf5ecee02e87b Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 10:47:35 -0800
Subject: [PATCH 09/16] add doctest as integration test

---
 native_implemented/otp/tests/internal/lib/erlang.rs         | 2 ++
 .../otp/tests/internal/lib/erlang/encode_unsigned_1.rs      | 1 +
 .../internal/lib/erlang/encode_unsigned_1/doctest/init.erl  | 6 ++++++
 3 files changed, 9 insertions(+)
 create mode 100644 native_implemented/otp/tests/internal/lib/erlang/encode_unsigned_1.rs
 create mode 100644 native_implemented/otp/tests/internal/lib/erlang/encode_unsigned_1/doctest/init.erl

diff --git a/native_implemented/otp/tests/internal/lib/erlang.rs b/native_implemented/otp/tests/internal/lib/erlang.rs
index 8d889fc0e..03f8b9a2d 100644
--- a/native_implemented/otp/tests/internal/lib/erlang.rs
+++ b/native_implemented/otp/tests/internal/lib/erlang.rs
@@ -68,6 +68,8 @@ pub mod div_2;
 pub mod divide_2;
 #[path = "erlang/element_2.rs"]
 pub mod element_2;
+#[path = "erlang/encode_unsigned_1.rs"]
+pub mod encode_unsigned_1;
 #[path = "erlang/erase_0.rs"]
 pub mod erase_0;
 #[path = "erlang/erase_1.rs"]
diff --git a/native_implemented/otp/tests/internal/lib/erlang/encode_unsigned_1.rs b/native_implemented/otp/tests/internal/lib/erlang/encode_unsigned_1.rs
new file mode 100644
index 000000000..654449c50
--- /dev/null
+++ b/native_implemented/otp/tests/internal/lib/erlang/encode_unsigned_1.rs
@@ -0,0 +1 @@
+test_stdout!(doctest, "<<169,138,199>>\n");
diff --git a/native_implemented/otp/tests/internal/lib/erlang/encode_unsigned_1/doctest/init.erl b/native_implemented/otp/tests/internal/lib/erlang/encode_unsigned_1/doctest/init.erl
new file mode 100644
index 000000000..4fde2f420
--- /dev/null
+++ b/native_implemented/otp/tests/internal/lib/erlang/encode_unsigned_1/doctest/init.erl
@@ -0,0 +1,6 @@
+-module(init).
+-export([start/0]).
+-import(erlang, [display/1]).
+
+start() ->
+  display(erlang:encode_unsigned(11111111)).

From ebff6bc311bf93b0e85ddf8dba7cf9fe1f6b23da Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 11:13:02 -0800
Subject: [PATCH 10/16] move to module binary

---
 native_implemented/otp/src/binary.rs                     | 9 +++++++++
 .../otp/src/{erlang => binary}/encode_unsigned_1.rs      | 2 +-
 .../otp/src/{erlang => binary}/encode_unsigned_1/test.rs | 2 +-
 native_implemented/otp/src/erlang.rs                     | 1 -
 4 files changed, 11 insertions(+), 3 deletions(-)
 rename native_implemented/otp/src/{erlang => binary}/encode_unsigned_1.rs (96%)
 rename native_implemented/otp/src/{erlang => binary}/encode_unsigned_1/test.rs (98%)

diff --git a/native_implemented/otp/src/binary.rs b/native_implemented/otp/src/binary.rs
index fdfcfbb1b..b4288e15b 100644
--- a/native_implemented/otp/src/binary.rs
+++ b/native_implemented/otp/src/binary.rs
@@ -1,4 +1,5 @@
 pub mod to_term;
+pub mod encode_unsigned_1;
 
 use std::backtrace::Backtrace;
 use std::convert::TryInto;
@@ -11,6 +12,14 @@ use liblumen_alloc::erts::exception::{self, ArcError, Exception, InternalExcepti
 use liblumen_alloc::erts::term::prelude::*;
 use liblumen_alloc::Process;
 
+pub fn module() -> Atom {
+    Atom::from_str("binary")
+}
+
+pub fn module_id() -> usize {
+    module().id()
+}
+
 pub struct PartRange {
     pub byte_offset: usize,
     pub byte_len: usize,
diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1.rs b/native_implemented/otp/src/binary/encode_unsigned_1.rs
similarity index 96%
rename from native_implemented/otp/src/erlang/encode_unsigned_1.rs
rename to native_implemented/otp/src/binary/encode_unsigned_1.rs
index 5177c0bf5..4082da7c6 100644
--- a/native_implemented/otp/src/erlang/encode_unsigned_1.rs
+++ b/native_implemented/otp/src/binary/encode_unsigned_1.rs
@@ -10,7 +10,7 @@ use num_bigint::Sign;
 
 /// Returns the smallest possible representation in a binary digit representation for the given big
 /// endian unsigned integer.
-#[native_implemented::function(erlang:encode_unsigned/1)]
+#[native_implemented::function(binary:encode_unsigned/1)]
 pub fn result(process: &Process, term: Term) -> exception::Result<Term> {
     match term.decode().unwrap() {
         TypedTerm::SmallInteger(small_integer) => {
diff --git a/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs b/native_implemented/otp/src/binary/encode_unsigned_1/test.rs
similarity index 98%
rename from native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
rename to native_implemented/otp/src/binary/encode_unsigned_1/test.rs
index 072c3fe71..86484b8f4 100644
--- a/native_implemented/otp/src/erlang/encode_unsigned_1/test.rs
+++ b/native_implemented/otp/src/binary/encode_unsigned_1/test.rs
@@ -1,4 +1,4 @@
-use crate::erlang::encode_unsigned_1::result;
+use crate::binary::encode_unsigned_1::result;
 use crate::test::with_process;
 use crate::test::*;
 use liblumen_alloc::erts::term::prelude::*;
diff --git a/native_implemented/otp/src/erlang.rs b/native_implemented/otp/src/erlang.rs
index 8793ebadc..352421b10 100644
--- a/native_implemented/otp/src/erlang.rs
+++ b/native_implemented/otp/src/erlang.rs
@@ -49,7 +49,6 @@ pub mod display_1;
 pub mod div_2;
 pub mod divide_2;
 pub mod element_2;
-pub mod encode_unsigned_1;
 pub mod erase_0;
 pub mod erase_1;
 pub mod error_1;

From 32e04336f3d916686c5e595c5e45d99040a45672 Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 11:20:44 -0800
Subject: [PATCH 11/16] move integration test to binary module

---
 native_implemented/otp/tests/internal/lib/binary.rs             | 2 ++
 .../tests/internal/lib/{erlang => binary}/encode_unsigned_1.rs  | 0
 .../lib/{erlang => binary}/encode_unsigned_1/doctest/init.erl   | 2 +-
 native_implemented/otp/tests/internal/lib/erlang.rs             | 2 --
 4 files changed, 3 insertions(+), 3 deletions(-)
 create mode 100644 native_implemented/otp/tests/internal/lib/binary.rs
 rename native_implemented/otp/tests/internal/lib/{erlang => binary}/encode_unsigned_1.rs (100%)
 rename native_implemented/otp/tests/internal/lib/{erlang => binary}/encode_unsigned_1/doctest/init.erl (63%)

diff --git a/native_implemented/otp/tests/internal/lib/binary.rs b/native_implemented/otp/tests/internal/lib/binary.rs
new file mode 100644
index 000000000..74000ed79
--- /dev/null
+++ b/native_implemented/otp/tests/internal/lib/binary.rs
@@ -0,0 +1,2 @@
+#[path = "binary/encode_unsigned_1.rs"]
+pub mod encode_unsigned_1;
\ No newline at end of file
diff --git a/native_implemented/otp/tests/internal/lib/erlang/encode_unsigned_1.rs b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1.rs
similarity index 100%
rename from native_implemented/otp/tests/internal/lib/erlang/encode_unsigned_1.rs
rename to native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1.rs
diff --git a/native_implemented/otp/tests/internal/lib/erlang/encode_unsigned_1/doctest/init.erl b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/doctest/init.erl
similarity index 63%
rename from native_implemented/otp/tests/internal/lib/erlang/encode_unsigned_1/doctest/init.erl
rename to native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/doctest/init.erl
index 4fde2f420..3117c05b3 100644
--- a/native_implemented/otp/tests/internal/lib/erlang/encode_unsigned_1/doctest/init.erl
+++ b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/doctest/init.erl
@@ -3,4 +3,4 @@
 -import(erlang, [display/1]).
 
 start() ->
-  display(erlang:encode_unsigned(11111111)).
+  display(binary:encode_unsigned(11111111)).
diff --git a/native_implemented/otp/tests/internal/lib/erlang.rs b/native_implemented/otp/tests/internal/lib/erlang.rs
index 03f8b9a2d..8d889fc0e 100644
--- a/native_implemented/otp/tests/internal/lib/erlang.rs
+++ b/native_implemented/otp/tests/internal/lib/erlang.rs
@@ -68,8 +68,6 @@ pub mod div_2;
 pub mod divide_2;
 #[path = "erlang/element_2.rs"]
 pub mod element_2;
-#[path = "erlang/encode_unsigned_1.rs"]
-pub mod encode_unsigned_1;
 #[path = "erlang/erase_0.rs"]
 pub mod erase_0;
 #[path = "erlang/erase_1.rs"]

From b807dcc2e066096b7e79dd7c0b885877de6aac32 Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 11:29:55 -0800
Subject: [PATCH 12/16] hook in the binary integration test module

---
 native_implemented/otp/tests/internal/lib.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/native_implemented/otp/tests/internal/lib.rs b/native_implemented/otp/tests/internal/lib.rs
index 8ada4ba80..e54e05371 100644
--- a/native_implemented/otp/tests/internal/lib.rs
+++ b/native_implemented/otp/tests/internal/lib.rs
@@ -1,3 +1,5 @@
+#[path = "lib/binary.rs"]
+pub mod binary;
 #[path = "lib/erlang.rs"]
 pub mod erlang;
 #[path = "lib/maps.rs"]

From b31bdf07b3c4deb2638afa31d7dbdd351669bc2e Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 11:30:34 -0800
Subject: [PATCH 13/16] auto-formatting

---
 native_implemented/otp/src/binary.rs                | 2 +-
 native_implemented/otp/tests/internal/lib/binary.rs | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/native_implemented/otp/src/binary.rs b/native_implemented/otp/src/binary.rs
index b4288e15b..c2e9cb3f7 100644
--- a/native_implemented/otp/src/binary.rs
+++ b/native_implemented/otp/src/binary.rs
@@ -1,5 +1,5 @@
-pub mod to_term;
 pub mod encode_unsigned_1;
+pub mod to_term;
 
 use std::backtrace::Backtrace;
 use std::convert::TryInto;
diff --git a/native_implemented/otp/tests/internal/lib/binary.rs b/native_implemented/otp/tests/internal/lib/binary.rs
index 74000ed79..d26048ae3 100644
--- a/native_implemented/otp/tests/internal/lib/binary.rs
+++ b/native_implemented/otp/tests/internal/lib/binary.rs
@@ -1,2 +1,2 @@
 #[path = "binary/encode_unsigned_1.rs"]
-pub mod encode_unsigned_1;
\ No newline at end of file
+pub mod encode_unsigned_1;

From edab51eff2a330bed7ec1c736ed7bb4908a8fb46 Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 11:57:39 -0800
Subject: [PATCH 14/16] migrate integration test with_smallest_big_int

---
 .../otp/tests/internal/lib/binary/encode_unsigned_1.rs      | 1 +
 .../binary/encode_unsigned_1/with_smallest_big_int/init.erl | 6 ++++++
 2 files changed, 7 insertions(+)
 create mode 100644 native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/with_smallest_big_int/init.erl

diff --git a/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1.rs b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1.rs
index 654449c50..3320210dd 100644
--- a/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1.rs
+++ b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1.rs
@@ -1 +1,2 @@
 test_stdout!(doctest, "<<169,138,199>>\n");
+test_stdout!(with_smallest_big_int, "<<64,0,0,0,0,0>>\n");
diff --git a/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/with_smallest_big_int/init.erl b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/with_smallest_big_int/init.erl
new file mode 100644
index 000000000..d7d9349e4
--- /dev/null
+++ b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/with_smallest_big_int/init.erl
@@ -0,0 +1,6 @@
+-module(init).
+-export([start/0]).
+-import(erlang, [display/1]).
+
+start() ->
+  display(binary:encode_unsigned(70368744177664)).

From 112820f08118a0d357b3a6afd774762498307eb4 Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 13:20:56 -0800
Subject: [PATCH 15/16] migrate more integration tests

---
 .../tests/internal/lib/binary/encode_unsigned_1.rs |  2 ++
 .../with_negative_integer/init.erl                 | 11 +++++++++++
 .../encode_unsigned_1/with_non_integer/init.erl    | 14 ++++++++++++++
 3 files changed, 27 insertions(+)
 create mode 100644 native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/with_negative_integer/init.erl
 create mode 100644 native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/with_non_integer/init.erl

diff --git a/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1.rs b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1.rs
index 3320210dd..60cf74172 100644
--- a/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1.rs
+++ b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1.rs
@@ -1,2 +1,4 @@
 test_stdout!(doctest, "<<169,138,199>>\n");
 test_stdout!(with_smallest_big_int, "<<64,0,0,0,0,0>>\n");
+test_stdout!(with_non_integer, "{caught, error, badarg}\n{caught, error, badarg}\n{caught, error, badarg}\n");
+test_stdout!(with_negative_integer, "{caught, error, badarg}\n{caught, error, badarg}\n");
diff --git a/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/with_negative_integer/init.erl b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/with_negative_integer/init.erl
new file mode 100644
index 000000000..36e5b1e1c
--- /dev/null
+++ b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/with_negative_integer/init.erl
@@ -0,0 +1,11 @@
+-module(init).
+-export([start/0]).
+-import(erlang, [display/1]).
+
+start() ->
+  test:caught(fun () ->
+    display(binary:encode_unsigned(-1))
+  end),
+  test:caught(fun () ->
+    display(binary:encode_unsigned(-70368744177664))
+  end).
\ No newline at end of file
diff --git a/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/with_non_integer/init.erl b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/with_non_integer/init.erl
new file mode 100644
index 000000000..f060d0e56
--- /dev/null
+++ b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/with_non_integer/init.erl
@@ -0,0 +1,14 @@
+-module(init).
+-export([start/0]).
+-import(erlang, [display/1]).
+
+start() ->
+  test:caught(fun () ->
+    display(binary:encode_unsigned(nil))
+  end),
+  test:caught(fun () ->
+    display(binary:encode_unsigned(foo))
+  end),
+  test:caught(fun () ->
+    display(binary:encode_unsigned("foo"))
+  end).
\ No newline at end of file

From 25d0dd4aa80da69154caf088a3642e4fcdfd6bb9 Mon Sep 17 00:00:00 2001
From: Mike Wilkerson <mwilkerson@gmail.com>
Date: Mon, 2 Nov 2020 14:22:40 -0800
Subject: [PATCH 16/16] implement remaining tests as integration tests

---
 .../internal/lib/binary/encode_unsigned_1.rs  | 26 +++++++++++++++++--
 .../init.erl                                  |  6 +++++
 .../init.erl                                  |  6 +++++
 .../init.erl                                  |  6 +++++
 .../init.erl                                  |  6 +++++
 5 files changed, 48 insertions(+), 2 deletions(-)
 create mode 100644 native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_big_int_encoded_bytes_have_significant_trailing_zeros/init.erl
 create mode 100644 native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_big_int_encoded_bytes_have_zeros_in_the_middle/init.erl
 create mode 100644 native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_small_int_encoded_bytes_have_significant_trailing_zeros/init.erl
 create mode 100644 native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_small_int_encoded_bytes_have_zeros_in_the_middle/init.erl

diff --git a/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1.rs b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1.rs
index 60cf74172..6b7538965 100644
--- a/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1.rs
+++ b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1.rs
@@ -1,4 +1,26 @@
 test_stdout!(doctest, "<<169,138,199>>\n");
 test_stdout!(with_smallest_big_int, "<<64,0,0,0,0,0>>\n");
-test_stdout!(with_non_integer, "{caught, error, badarg}\n{caught, error, badarg}\n{caught, error, badarg}\n");
-test_stdout!(with_negative_integer, "{caught, error, badarg}\n{caught, error, badarg}\n");
+test_stdout!(
+    with_non_integer,
+    "{caught, error, badarg}\n{caught, error, badarg}\n{caught, error, badarg}\n"
+);
+test_stdout!(
+    with_negative_integer,
+    "{caught, error, badarg}\n{caught, error, badarg}\n"
+);
+test_stdout!(
+    when_big_int_encoded_bytes_have_significant_trailing_zeros,
+    "<<64,0,0,0,0,0>>\n"
+);
+test_stdout!(
+    when_small_int_encoded_bytes_have_significant_trailing_zeros,
+    "<<1,0,0,0>>\n"
+);
+test_stdout!(
+    when_small_int_encoded_bytes_have_zeros_in_the_middle,
+    "<<169,0,199>>\n"
+);
+test_stdout!(
+    when_big_int_encoded_bytes_have_zeros_in_the_middle,
+    "<<64,0,0,0,0,1>>\n"
+);
diff --git a/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_big_int_encoded_bytes_have_significant_trailing_zeros/init.erl b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_big_int_encoded_bytes_have_significant_trailing_zeros/init.erl
new file mode 100644
index 000000000..0b4f10f34
--- /dev/null
+++ b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_big_int_encoded_bytes_have_significant_trailing_zeros/init.erl
@@ -0,0 +1,6 @@
+-module(init).
+-export([start/0]).
+-import(erlang, [display/1]).
+
+start() ->
+  display(binary:encode_unsigned(70368744177665)).
diff --git a/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_big_int_encoded_bytes_have_zeros_in_the_middle/init.erl b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_big_int_encoded_bytes_have_zeros_in_the_middle/init.erl
new file mode 100644
index 000000000..0b4f10f34
--- /dev/null
+++ b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_big_int_encoded_bytes_have_zeros_in_the_middle/init.erl
@@ -0,0 +1,6 @@
+-module(init).
+-export([start/0]).
+-import(erlang, [display/1]).
+
+start() ->
+  display(binary:encode_unsigned(70368744177665)).
diff --git a/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_small_int_encoded_bytes_have_significant_trailing_zeros/init.erl b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_small_int_encoded_bytes_have_significant_trailing_zeros/init.erl
new file mode 100644
index 000000000..65d6a8035
--- /dev/null
+++ b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_small_int_encoded_bytes_have_significant_trailing_zeros/init.erl
@@ -0,0 +1,6 @@
+-module(init).
+-export([start/0]).
+-import(erlang, [display/1]).
+
+start() ->
+  display(binary:encode_unsigned(16777216)).
diff --git a/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_small_int_encoded_bytes_have_zeros_in_the_middle/init.erl b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_small_int_encoded_bytes_have_zeros_in_the_middle/init.erl
new file mode 100644
index 000000000..26a486d6e
--- /dev/null
+++ b/native_implemented/otp/tests/internal/lib/binary/encode_unsigned_1/when_small_int_encoded_bytes_have_zeros_in_the_middle/init.erl
@@ -0,0 +1,6 @@
+-module(init).
+-export([start/0]).
+-import(erlang, [display/1]).
+
+start() ->
+  display(binary:encode_unsigned(11075783)).