really test decode_varint_slow (#977)

* really test decode_varint_slow instead of passing it slices that have already been emptied

* reborrow with methods not &*

---------

Co-authored-by: Lucio Franco <luciofranco14@gmail.com>

conformance/src/main.rs

@@ -27,7 +27,7 @@ fn main() -> io::Result<()> {
         bytes.resize(len, 0);
         io::stdin().read_exact(&mut bytes)?;
 
-        let result = match ConformanceRequest::decode(&*bytes) {
+        let result = match ConformanceRequest::decode(bytes.as_slice()) {
             Ok(request) => handle_request(request),
             Err(error) => conformance_response::Result::ParseError(format!("{:?}", error)),
         };
@@ -93,7 +93,7 @@ fn handle_request(request: ConformanceRequest) -> conformance_response::Result {
         Some(conformance_request::Payload::ProtobufPayload(buf)) => buf,
     };
 
-    let roundtrip = match &*request.message_type {
+    let roundtrip = match request.message_type.as_str() {
         "protobuf_test_messages.proto2.TestAllTypesProto2" => roundtrip::<TestAllTypesProto2>(&buf),
         "protobuf_test_messages.proto3.TestAllTypesProto3" => roundtrip::<TestAllTypesProto3>(&buf),
         _ => {

prost-build/src/ast.rs

@@ -190,7 +190,7 @@ where
                 fn map_codeblock(kind: CodeBlockKind) -> CodeBlockKind {
                     match kind {
                         CodeBlockKind::Fenced(s) => {
-                            if &*s == "rust" {
+                            if s.as_ref() == "rust" {
                                 CodeBlockKind::Fenced("compile_fail".into())
                             } else {
                                 CodeBlockKind::Fenced(format!("text,{}", s).into())

prost-build/src/lib.rs

@@ -1149,7 +1149,7 @@ impl Config {
                 ),
             )
         })?;
-        let file_descriptor_set = FileDescriptorSet::decode(&*buf).map_err(|error| {
+        let file_descriptor_set = FileDescriptorSet::decode(buf.as_slice()).map_err(|error| {
             Error::new(
                 ErrorKind::InvalidInput,
                 format!("invalid FileDescriptorSet: {}", error),

prost-types/src/lib.rs

@@ -66,7 +66,7 @@ impl Any {
         ) {
             (Some(expected), Some(actual)) => {
                 if expected == actual {
-                    return Ok(M::decode(&*self.value)?);
+                    return Ok(M::decode(self.value.as_slice())?);
                 }
             }
             _ => (),

protobuf/benches/dataset.rs

@@ -16,7 +16,7 @@ fn load_dataset(dataset: &Path) -> Result<BenchmarkDataset, Box<dyn Error>> {
     let mut f = File::open(dataset)?;
     let mut buf = Vec::new();
     f.read_to_end(&mut buf)?;
-    Ok(BenchmarkDataset::decode(&*buf)?)
+    Ok(BenchmarkDataset::decode(buf.as_slice())?)
 }
 
 fn benchmark_dataset<M>(criterion: &mut Criterion, name: &str, dataset: &'static Path)

src/encoding.rs

@@ -1602,7 +1602,7 @@ mod test {
 
     #[test]
     fn varint() {
-        fn check(value: u64, mut encoded: &[u8]) {
+        fn check(value: u64, encoded: &[u8]) {
             // Small buffer.
             let mut buf = Vec::with_capacity(1);
             encode_varint(value, &mut buf);
@@ -1615,11 +1615,11 @@ mod test {
 
             assert_eq!(encoded_len_varint(value), encoded.len());
 
-            let roundtrip_value =
-                decode_varint(&mut <&[u8]>::clone(&encoded)).expect("decoding failed");
+            let roundtrip_value = decode_varint(&mut encoded.clone()).expect("decoding failed");
             assert_eq!(value, roundtrip_value);
 
-            let roundtrip_value = decode_varint_slow(&mut encoded).expect("slow decoding failed");
+            let roundtrip_value =
+                decode_varint_slow(&mut encoded.clone()).expect("slow decoding failed");
             assert_eq!(value, roundtrip_value);
         }
 
@@ -1680,11 +1680,10 @@ mod test {
 
     #[test]
     fn varint_overflow() {
-        let mut u64_max_plus_one: &[u8] =
-            &[0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x02];
+        let u64_max_plus_one: &[u8] = &[0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x02];
 
-        decode_varint(&mut u64_max_plus_one).expect_err("decoding u64::MAX + 1 succeeded");
-        decode_varint_slow(&mut u64_max_plus_one)
+        decode_varint(&mut u64_max_plus_one.clone()).expect_err("decoding u64::MAX + 1 succeeded");
+        decode_varint_slow(&mut u64_max_plus_one.clone())
             .expect_err("slow decoding u64::MAX + 1 succeeded");
     }
 

tests/src/lib.rs

@@ -199,6 +199,7 @@ where
     if let Err(error) = all_types.encode(&mut buf1) {
         return RoundtripResult::Error(error.into());
     }
+    let buf1 = buf1;
     if encoded_len != buf1.len() {
         return RoundtripResult::Error(anyhow!(
             "expected encoded len ({}) did not match actual encoded len ({})",
@@ -207,7 +208,7 @@ where
         ));
     }
 
-    let roundtrip = match M::decode(&*buf1) {
+    let roundtrip = match M::decode(buf1.as_slice()) {
         Ok(roundtrip) => roundtrip,
         Err(error) => return RoundtripResult::Error(anyhow::Error::new(error)),
     };
@@ -216,6 +217,7 @@ where
     if let Err(error) = roundtrip.encode(&mut buf2) {
         return RoundtripResult::Error(error.into());
     }
+    let buf2 = buf2;
     let buf3 = roundtrip.encode_to_vec();
 
     /*
@@ -249,7 +251,7 @@ where
     msg.encode(&mut buf).unwrap();
     assert_eq!(expected_len, buf.len());
 
-    let mut buf = &*buf;
+    let mut buf = buf.as_slice();
     let roundtrip = M::decode(&mut buf).unwrap();
 
     assert!(
@@ -430,7 +432,7 @@ mod tests {
 
             let mut buf = Vec::new();
             a.encode(&mut buf).unwrap();
-            A::decode(&*buf).map(|_| ())
+            A::decode(buf.as_slice()).map(|_| ())
         }
 
         assert!(build_and_roundtrip(100).is_ok());
@@ -453,7 +455,7 @@ mod tests {
 
             let mut buf = Vec::new();
             a.encode(&mut buf).unwrap();
-            A::decode(&*buf).map(|_| ())
+            A::decode(buf.as_slice()).map(|_| ())
         }
 
         assert!(build_and_roundtrip(99).is_ok());
@@ -476,7 +478,7 @@ mod tests {
 
             let mut buf = Vec::new();
             a.encode(&mut buf).unwrap();
-            NestedGroup2::decode(&*buf).map(|_| ())
+            NestedGroup2::decode(buf.as_slice()).map(|_| ())
         }
 
         assert!(build_and_roundtrip(50).is_ok());
@@ -497,7 +499,7 @@ mod tests {
 
             let mut buf = Vec::new();
             c.encode(&mut buf).unwrap();
-            C::decode(&*buf).map(|_| ())
+            C::decode(buf.as_slice()).map(|_| ())
         }
 
         assert!(build_and_roundtrip(100).is_ok());
@@ -518,7 +520,7 @@ mod tests {
 
             let mut buf = Vec::new();
             d.encode(&mut buf).unwrap();
-            D::decode(&*buf).map(|_| ())
+            D::decode(buf.as_slice()).map(|_| ())
         }
 
         assert!(build_and_roundtrip(50).is_ok());
@@ -681,7 +683,7 @@ mod tests {
 
         let mut bytes = Vec::new();
         msg2.encode(&mut bytes).unwrap();
-        assert_eq!(&*bytes, msg2_bytes);
+        assert_eq!(bytes.as_slice(), msg2_bytes);
 
         assert_eq!(groups::Test2::decode(msg2_bytes), Ok(msg2));
     }