[bencode] Implement round trip test

src/bencode.rs

@@ -2,3 +2,47 @@ pub mod custom;
 pub mod de;
 pub mod ser;
 pub  mod error;
+
+#[cfg(test)]
+mod test {
+    use std::collections::HashMap;
+    use serde::{Deserialize, Serialize};
+    use crate::bencode::de::from_bytes;
+    use crate::bencode::ser::to_bytes;
+
+    #[test]
+    fn test_roundtrip() {
+        #[derive(Serialize, Deserialize, PartialEq, Debug)]
+        struct A {
+            l: Vec<String>,
+            li: Vec<i32>,
+            m: HashMap<String, String>,
+            b: Vec<[u8; 4]>
+        }
+
+        let a = A {
+            l: vec!["foo".to_string(), "bar".to_string(), "".to_string(), "💩".to_string()],
+            li: vec![18, 7, 26, 8, 9],
+            m: HashMap::from([
+                ("foo".to_string(), "bar".to_string()),
+                ("💩".to_string(), "🤷‍♂️".to_string()),
+                ("18".to_string(), "asdf".to_string())
+            ]),
+            b: vec![
+                [4, 26, 7, 18],
+                [24, 13, 12, 4],
+                [8, 9, 10, 11]
+            ],
+        };
+
+        let ser = to_bytes(&a).unwrap();
+
+        let de = from_bytes(&ser).unwrap();
+
+        assert_eq!(a, de);
+
+        let ser2 = to_bytes(&de).unwrap();
+
+        assert_eq!(ser, ser2)
+    }
+}

src/bencode/ser.rs

@@ -4,14 +4,39 @@ use serde::{ser, Serialize};
 
 use crate::bencode::error::{Error, Result};
 
+#[derive(PartialEq)]
+enum TupleState {
+    None,
+    Unknown,
+    List,
+    ByteString,
+}
+
 pub struct Serializer {
     output: Vec<u8>,
+    tuple_state: TupleState,
+    tuple_len: usize,
 }
 
 impl Serializer {
     fn new() -> Self {
         Serializer {
             output: Vec::new(),
+            tuple_state: TupleState::None,
+            tuple_len: 0,
+        }
+    }
+
+    fn write_tuple_start_bytes(&mut self) {
+        if self.tuple_state == TupleState::Unknown {
+            self.tuple_state = TupleState::ByteString;
+            self.output.extend(format!("{}:", self.tuple_len).into_bytes());
+        }
+    }
+    fn write_tuple_start_list(&mut self) {
+        if self.tuple_state == TupleState::Unknown {
+            self.tuple_state = TupleState::List;
+            self.output.push('l' as u8);
         }
     }
 }
@@ -54,37 +79,47 @@ impl<'a> ser::Serializer for &'a mut Serializer
     type SerializeStruct = MapSerializer<'a>;
     type SerializeStructVariant = Self;
 
-    fn serialize_bool(self, v: bool) -> Result<()> {
+    fn serialize_bool(self, _v: bool) -> Result<()> {
         Err(Error::WontImplement)
     }
 
     fn serialize_i8(self, v: i8) -> Result<()> {
+        self.write_tuple_start_list();
         self.output.extend(format!("i{v}e").into_bytes());
         Ok(())
     }
 
     fn serialize_i16(self, v: i16) -> Result<()> {
+        self.write_tuple_start_list();
         self.output.extend(format!("i{v}e").into_bytes());
         Ok(())
     }
 
     fn serialize_i32(self, v: i32) -> Result<()> {
+        self.write_tuple_start_list();
         self.output.extend(format!("i{v}e").into_bytes());
         Ok(())
     }
 
     fn serialize_i64(self, v: i64) -> Result<()> {
+        self.write_tuple_start_list();
         self.output.extend(format!("i{v}e").into_bytes());
         Ok(())
     }
 
     fn serialize_i128(self, v: i128) -> Result<()> {
+        self.write_tuple_start_list();
         self.output.extend(format!("i{v}e").into_bytes());
         Ok(())
     }
 
     fn serialize_u8(self, v: u8) -> Result<()> {
-        todo!()
+        if self.tuple_state == TupleState::None {
+            return Err(Error::WontImplement);
+        }
+        self.write_tuple_start_bytes();
+        self.output.push(v);
+        Ok(())
     }
 
     fn serialize_u16(self, _v: u16) -> Result<()> {
@@ -112,6 +147,7 @@ impl<'a> ser::Serializer for &'a mut Serializer
     }
 
     fn serialize_char(self, v: char) -> Result<()> {
+        self.write_tuple_start_list();
         self.output.extend(format!("{}:", v.len_utf8()).into_bytes());
         let mut b = [0; 4];
         v.encode_utf8(&mut b);
@@ -120,12 +156,14 @@ impl<'a> ser::Serializer for &'a mut Serializer
     }
 
     fn serialize_str(self, v: &str) -> Result<()> {
+        self.write_tuple_start_list();
         self.output.extend(format!("{}:", v.len()).into_bytes());
         self.output.extend(v.as_bytes());
         Ok(())
     }
 
     fn serialize_bytes(self, v: &[u8]) -> Result<()> {
+        self.write_tuple_start_list();
         self.output.extend(format!("{}:", v.len()).into_bytes());
         self.output.extend(v);
         Ok(())
@@ -139,6 +177,7 @@ impl<'a> ser::Serializer for &'a mut Serializer
     where
         T: ?Sized + Serialize
     {
+        self.write_tuple_start_list();
         value.serialize(self)
     }
 
@@ -158,10 +197,11 @@ impl<'a> ser::Serializer for &'a mut Serializer
     where
         T: ?Sized + Serialize
     {
+        self.write_tuple_start_list();
         value.serialize(self)
     }
 
-    fn serialize_newtype_variant<T>(self, name: &'static str, variant_index: u32, variant: &'static str, value: &T) -> Result<()>
+    fn serialize_newtype_variant<T>(self, _name: &'static str, _variant_index: u32, _variant: &'static str, _value: &T) -> Result<()>
     where
         T: ?Sized + Serialize
     {
@@ -169,13 +209,18 @@ impl<'a> ser::Serializer for &'a mut Serializer
     }
 
     fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq> {
+        self.write_tuple_start_list();
         self.output.push('l' as u8);
         Ok(self)
     }
 
     fn serialize_tuple(self, len: usize) -> Result<Self::SerializeTuple> {
-        println!("tuple");
-        todo!()
+        if self.tuple_state != TupleState::None {
+            return Err(Error::WontImplement)
+        }
+        self.tuple_state = TupleState::Unknown;
+        self.tuple_len = len;
+        Ok(self)
     }
 
     fn serialize_tuple_struct(self, _name: &'static str, _len: usize) -> Result<Self::SerializeTupleStruct> {
@@ -187,6 +232,7 @@ impl<'a> ser::Serializer for &'a mut Serializer
     }
 
     fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap> {
+        self.write_tuple_start_list();
         self.output.push('d' as u8);
         Ok(MapSerializer{
             super_serializer: self,
@@ -197,6 +243,7 @@ impl<'a> ser::Serializer for &'a mut Serializer
     }
 
     fn serialize_struct(self, _name: &'static str, _len: usize) -> Result<Self::SerializeStruct> {
+        self.write_tuple_start_list();
         self.output.push('d' as u8);
         Ok(MapSerializer{
             super_serializer: self,
@@ -236,11 +283,15 @@ impl <'a> ser::SerializeTuple for &'a mut Serializer {
     where
         T: ?Sized + Serialize
     {
-        todo!()
+        value.serialize(&mut **self)
     }
 
     fn end(self) -> Result<()> {
-        todo!()
+        if self.tuple_state == TupleState::List {
+            self.output.push('e' as u8);
+        }
+        self.tuple_state = TupleState::None;
+        Ok(())
     }
 }
 
@@ -385,7 +436,7 @@ impl <'a> ser::SerializeStructVariant for &'a mut Serializer {
 mod test {
     use std::collections::HashMap;
     use serde::Serialize;
-    use crate::bencode::ser::to_string;
+    use crate::bencode::ser::{to_bytes, to_string};
 
     #[test]
     fn test_int() {
@@ -435,7 +486,7 @@ mod test {
     }
 
     #[test]
-    fn test_dict() {
+    fn test_struct() {
         #[derive(Serialize)]
         struct A {
             a: i32,
@@ -459,6 +510,26 @@ mod test {
             o2: None,
         }).unwrap(),
             "d1:lli3ei7ei9ee1:md3:bari18e3:fooi23ee1:o3:baze"
-        )
+        );
+
+        #[derive(Serialize)]
+        struct C {
+            d: HashMap<String, [u8; 3]>
+        }
+
+        let mut expected = "d1:dd3:bar3:".as_bytes().to_vec();
+        expected.extend(vec![12, 18, 9]);
+        expected.extend("3:foo3:".as_bytes());
+        expected.extend(vec![1, 2, 3]);
+        expected.extend("ee".as_bytes());
+
+        assert_eq!(to_bytes(&C{
+            d: HashMap::from([
+                ("foo".to_string(), [1, 2, 3]),
+                ("bar".to_string(), [12, 18, 9]),
+            ])
+        }).unwrap(),
+            expected
+        );
     }
 }