1 files changed, 91 insertions, 0 deletions
diff --git a/compiler/rustc_serialize/tests/leb128.rs b/compiler/rustc_serialize/tests/leb128.rs
new file mode 100644
index 000000000..314c07db9
--- /dev/null
+++ b/compiler/rustc_serialize/tests/leb128.rs
@@ -0,0 +1,91 @@
+#![feature(maybe_uninit_slice)]
+#![feature(maybe_uninit_uninit_array)]
+
+use rustc_serialize::leb128::*;
+use std::mem::MaybeUninit;
+
+macro_rules! impl_test_unsigned_leb128 {
+    ($test_name:ident, $write_fn_name:ident, $read_fn_name:ident, $int_ty:ident) => {
+        #[test]
+        fn $test_name() {
+            // Test 256 evenly spaced values of integer range,
+            // integer max value, and some "random" numbers.
+            let mut values = Vec::new();
+
+            let increment = (1 as $int_ty) << ($int_ty::BITS - 8);
+            values.extend((0..256).map(|i| $int_ty::MIN + i * increment));
+
+            values.push($int_ty::MAX);
+
+            values.extend(
+                (-500..500).map(|i| (i as $int_ty).wrapping_mul(0x12345789ABCDEFu64 as $int_ty)),
+            );
+
+            let mut stream = Vec::new();
+
+            for &x in &values {
+                let mut buf = MaybeUninit::uninit_array();
+                stream.extend($write_fn_name(&mut buf, x));
+            }
+
+            let mut position = 0;
+            for &expected in &values {
+                let actual = $read_fn_name(&stream, &mut position);
+                assert_eq!(expected, actual);
+            }
+            assert_eq!(stream.len(), position);
+        }
+    };
+}
+
+impl_test_unsigned_leb128!(test_u16_leb128, write_u16_leb128, read_u16_leb128, u16);
+impl_test_unsigned_leb128!(test_u32_leb128, write_u32_leb128, read_u32_leb128, u32);
+impl_test_unsigned_leb128!(test_u64_leb128, write_u64_leb128, read_u64_leb128, u64);
+impl_test_unsigned_leb128!(test_u128_leb128, write_u128_leb128, read_u128_leb128, u128);
+impl_test_unsigned_leb128!(test_usize_leb128, write_usize_leb128, read_usize_leb128, usize);
+
+macro_rules! impl_test_signed_leb128 {
+    ($test_name:ident, $write_fn_name:ident, $read_fn_name:ident, $int_ty:ident) => {
+        #[test]
+        fn $test_name() {
+            // Test 256 evenly spaced values of integer range,
+            // integer max value, and some "random" numbers.
+            let mut values = Vec::new();
+
+            let mut value = $int_ty::MIN;
+            let increment = (1 as $int_ty) << ($int_ty::BITS - 8);
+
+            for _ in 0..256 {
+                values.push(value);
+                // The addition in the last loop iteration overflows.
+                value = value.wrapping_add(increment);
+            }
+
+            values.push($int_ty::MAX);
+
+            values.extend(
+                (-500..500).map(|i| (i as $int_ty).wrapping_mul(0x12345789ABCDEFi64 as $int_ty)),
+            );
+
+            let mut stream = Vec::new();
+
+            for &x in &values {
+                let mut buf = MaybeUninit::uninit_array();
+                stream.extend($write_fn_name(&mut buf, x));
+            }
+
+            let mut position = 0;
+            for &expected in &values {
+                let actual = $read_fn_name(&stream, &mut position);
+                assert_eq!(expected, actual);
+            }
+            assert_eq!(stream.len(), position);
+        }
+    };
+}
+
+impl_test_signed_leb128!(test_i16_leb128, write_i16_leb128, read_i16_leb128, i16);
+impl_test_signed_leb128!(test_i32_leb128, write_i32_leb128, read_i32_leb128, i32);
+impl_test_signed_leb128!(test_i64_leb128, write_i64_leb128, read_i64_leb128, i64);
+impl_test_signed_leb128!(test_i128_leb128, write_i128_leb128, read_i128_leb128, i128);
+impl_test_signed_leb128!(test_isize_leb128, write_isize_leb128, read_isize_leb128, isize);