tests and fixes

.gitignore

@@ -3,5 +3,4 @@
 
 /target
 
-*.class
+testing
-*.java

src/execute/mod.rs

@@ -1 +1,2 @@
-mod model;
+#[allow(dead_code)]
+mod model;

src/lib.rs

@@ -3,6 +3,6 @@ use crate::parse::{ClassFile, ParseErr};
 mod execute;
 mod parse;
 
-pub fn parse_class_file(file: Vec<u8>) -> Result<ClassFile, ParseErr> {
+pub fn parse_class_file(file: &[u8]) -> Result<ClassFile, ParseErr> {
     parse::parse_class_file(file)
 }

src/main.rs

@@ -4,7 +4,7 @@ fn main() {
     let file = "Test.class";
     let file = std::fs::read(file).unwrap();
 
-    let class_file = parse_class_file(file).unwrap();
+    let class_file = parse_class_file(&file).unwrap();
 
     println!("{:?}", class_file);
 }

src/parse/mod.rs

@@ -1,29 +1,26 @@
 mod model;
+#[cfg(test)]
+mod test;
+
 pub use model::*;
-use std::path::Prefix::Verbatim;
 
 #[derive(Debug)]
 pub struct ParseErr(String);
 
 pub type Result<T> = std::result::Result<T, ParseErr>;
 
-struct Data {
+#[derive(Copy, Clone)]
-    data: Vec<u1>,
+struct Data<'a> {
+    data: &'a [u1],
     pointer: usize,
 }
 
-pub fn parse_class_file(data: Vec<u1>) -> Result<ClassFile> {
+pub fn parse_class_file(data: &[u1]) -> Result<ClassFile> {
-    let mut data = Data { data, pointer: 0 };
+    let data = Data { data, pointer: 0 };
-    ClassFile::parse(&mut data)
+    ClassFile::parse(data)
 }
 
-impl From<Vec<u8>> for Data {
+impl<'a> Data<'a> {
-    fn from(data: Vec<u1>) -> Self {
-        Self { data, pointer: 0 }
-    }
-}
-
-impl Data {
     fn u1(&mut self) -> Result<u1> {
         let item = self.data.get(self.pointer).cloned();
         self.pointer += 1;
@@ -69,65 +66,55 @@ impl Data {
     }
 }
 
-pub trait Parse {
+trait Parse {
-    fn parse(data: &mut Data) -> Result<Self>
+    fn parse(data: Data) -> Result<Self>
     where
         Self: Sized;
 }
 
-pub trait ParseVec<T> {
+fn parse_vec<T: Parse, S: Into<usize>>(data: Data, len: S) -> Result<Vec<T>> {
-    fn parse_vec(data: &mut Data, len: usize) -> Result<Self>
+    let len = len.into();
-    where
+    let mut vec = Vec::with_capacity(len);
-        Self: Sized;
+    for _ in 0..len {
-}
+        vec.push(T::parse(data)?);
-
-impl<T: Parse> ParseVec<T> for Vec<T> {
-    fn parse_vec(data: &mut Data, len: usize) -> Result<Self> {
-        let mut vec = Vec::with_capacity(len);
-        for _ in 0..len {
-            vec.push(T::parse(data)?);
-        }
-        Ok(vec)
     }
+    Ok(vec)
 }
 
 macro_rules! parse_primitive {
-    ($value:ident) => {
+    ($($value:ident),*) => {
-        impl Parse for $value {
+        $(impl Parse for $value {
-            fn parse(data: &mut Data) -> Result<Self>
+            fn parse(mut data: Data) -> Result<Self>
             where
                 Self: Sized,
             {
                 data.$value()
             }
-        }
+        })*
     };
 }
 
-parse_primitive!(u1);
+parse_primitive!(u1, u2, u4);
-parse_primitive!(u2);
-parse_primitive!(u4);
 
 impl Parse for ClassFile {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         let magic = data.u4()?;
         assert_eq!(magic, 0xCAFEBABE);
         let minor_version = data.u2()?;
         let major_version = data.u2()?;
         let constant_pool_count = data.u2()?;
-        let constant_pool = Vec::parse_vec(data, constant_pool_count as usize)?;
+        let constant_pool = parse_vec(data, constant_pool_count - 1)?; // the minus one is important
         let access_flags = data.u2()?;
         let this_class = data.u2()?;
         let super_class = data.u2()?;
         let interfaces_count = data.u2()?;
-        let interfaces = Vec::parse_vec(data, interfaces_count as usize)?;
+        let interfaces = parse_vec(data, interfaces_count)?;
         let fields_count = data.u2()?;
-        let fields = Vec::parse_vec(data, fields_count as usize)?;
+        let fields = parse_vec(data, fields_count)?;
         let method_count = data.u2()?;
-        let methods = Vec::parse_vec(data, method_count as usize)?;
+        let methods = parse_vec(data, method_count)?;
         let attributes_count = data.u2()?;
-        let attributes = Vec::parse_vec(data, attributes_count as usize)?;
+        let attributes = parse_vec(data, attributes_count)?;
-        println!("los");
         Ok(Self {
             magic,
             minor_version,
@@ -150,7 +137,7 @@ impl Parse for ClassFile {
 }
 
 impl Parse for CpInfo {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         let tag = data.u1()?;
 
         Ok(match tag {
@@ -163,7 +150,7 @@ impl Parse for CpInfo {
                 class_index: data.u2()?,
                 name_and_type_index: data.u2()?,
             },
-            10 => Self::Methodref {
+            10 => Self::MethodRef {
                 tag,
                 class_index: data.u2()?,
                 name_and_type_index: data.u2()?,
@@ -203,7 +190,7 @@ impl Parse for CpInfo {
             1 => Self::Utf8 {
                 tag,
                 length: data.u2()?,
-                bytes: Vec::parse_vec(data, data.last_u2()? as usize)?,
+                bytes: parse_vec(data, data.last_u2()?)?,
             },
             15 => Self::MethodHandle {
                 tag,
@@ -225,41 +212,41 @@ impl Parse for CpInfo {
 }
 
 impl Parse for FieldInfo {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         Ok(Self {
             access_flags: data.u2()?,
             name_index: data.u2()?,
             descriptor_index: data.u2()?,
             attributes_count: data.u2()?,
-            attributes: Vec::parse_vec(data, data.last_u2()? as usize)?,
+            attributes: parse_vec(data, data.last_u2()?)?,
         })
     }
 }
 
 impl Parse for MethodInfo {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         Ok(Self {
             access_flags: data.u2()?,
             name_index: data.u2()?,
             descriptor_index: data.u2()?,
             attributes_count: data.u2()?,
-            attributes: Vec::parse_vec(data, data.last_u2()? as usize)?,
+            attributes: parse_vec(data, data.last_u2()?)?,
         })
     }
 }
 
 impl Parse for Attribute {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         Ok(Self {
             attribute_name_index: data.u2()?,
             attribute_length: data.u4()?,
-            attribute_content: Vec::parse_vec(data, data.last_u4()? as usize)?,
+            attribute_content: parse_vec(data, data.last_u4()? as usize)?,
         })
     }
 }
 
 impl Parse for AttributeCodeException {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(data: Data) -> Result<Self> {
         Ok(Self {
             start_pc: data.last_u2()?,
             end_pc: data.last_u2()?,
@@ -270,7 +257,7 @@ impl Parse for AttributeCodeException {
 }
 
 impl Parse for StackMapFrame {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         let frame_type = data.u1()?;
 
         Ok(match frame_type {
@@ -295,15 +282,15 @@ impl Parse for StackMapFrame {
             252..=254 => Self::AppendFrame {
                 frame_type,
                 offset_delta: data.u2()?,
-                locals: Vec::parse_vec(data, data.last_u2()? as usize)?,
+                locals: parse_vec(data, data.last_u2()?)?,
             },
             255 => Self::FullFrame {
                 frame_type,
                 offset_delta: data.u2()?,
                 number_of_locals: data.u2()?,
-                locals: Vec::parse_vec(data, data.last_u2()? as usize)?,
+                locals: parse_vec(data, data.last_u2()?)?,
                 number_of_stack_items: data.u2()?,
-                stack: Vec::parse_vec(data, data.last_u2()? as usize)?,
+                stack: parse_vec(data, data.last_u2()?)?,
             },
             _ => Err(ParseErr(format!(
                 "Invalid StackMapFrame type: {}",
@@ -314,7 +301,7 @@ impl Parse for StackMapFrame {
 }
 
 impl Parse for VerificationTypeInfo {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         let tag = data.u1()?;
         Ok(match tag {
             0 => Self::Top { tag },
@@ -341,7 +328,7 @@ impl Parse for VerificationTypeInfo {
 }
 
 impl Parse for AttributeInnerClass {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         Ok(Self {
             inner_class_info_index: data.u2()?,
             outer_class_info_index: data.u2()?,
@@ -352,7 +339,7 @@ impl Parse for AttributeInnerClass {
 }
 
 impl Parse for AttributeLineNumber {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         Ok(Self {
             start_pc: data.u2()?,
             line_number: data.u2()?,
@@ -361,7 +348,7 @@ impl Parse for AttributeLineNumber {
 }
 
 impl Parse for AttributeLocalVariableTable {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         Ok(Self {
             start_pc: data.u2()?,
             length: data.u2()?,
@@ -373,17 +360,17 @@ impl Parse for AttributeLocalVariableTable {
 }
 
 impl Parse for Annotation {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         Ok(Self {
             type_index: data.u2()?,
             num_element_value_pairs: data.u2()?,
-            element_value_pairs: Vec::parse_vec(data, data.last_u2()? as usize)?,
+            element_value_pairs: parse_vec(data, data.last_u2()?)?,
         })
     }
 }
 
 impl Parse for AnnotationElementValuePair {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         Ok(Self {
             element_name_index: data.u2()?,
             element_name_name: AnnotationElementValue::parse(data)?,
@@ -392,7 +379,7 @@ impl Parse for AnnotationElementValuePair {
 }
 
 impl Parse for AnnotationElementValue {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         Ok(Self {
             tag: data.u1()?,
             value: AnnotationElementValueValue::parse(data)?,
@@ -401,7 +388,7 @@ impl Parse for AnnotationElementValue {
 }
 
 impl Parse for AnnotationElementValueValue {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         let tag = data.last_u1()? as char;
         Ok(match tag {
             'B' | 'C' | 'D' | 'F' | 'I' | 'J' | 'S' | 'Z' | 's' => {
@@ -417,7 +404,7 @@ impl Parse for AnnotationElementValueValue {
             },
             '[' => Self::ArrayValue {
                 num_values: data.u2()?,
-                values: Vec::parse_vec(data, data.last_u2()? as usize)?,
+                values: parse_vec(data, data.last_u2()?)?,
             },
             _ => Err(ParseErr(format!(
                 "Invalid AnnotationElementValueValue tag: {}",
@@ -428,57 +415,20 @@ impl Parse for AnnotationElementValueValue {
 }
 
 impl Parse for ParameterAnnotation {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         Ok(Self {
             num_annotations: data.u2()?,
-            annotations: Vec::parse_vec(data, data.last_u2()? as usize)?,
+            annotations: parse_vec(data, data.last_u2()?)?,
         })
     }
 }
 
 impl Parse for BootstrapMethod {
-    fn parse(data: &mut Data) -> Result<Self> {
+    fn parse(mut data: Data) -> Result<Self> {
         Ok(Self {
             bootstrap_method_ref: data.u2()?,
             num_bootstrap_arguments: data.u2()?,
-            bootstrap_arguments: Vec::parse_vec(data, data.last_u2()? as usize)?,
+            bootstrap_arguments: parse_vec(data, data.last_u2()?)?,
         })
     }
 }
-
-#[cfg(test)]
-mod test {
-    use crate::parse::Data;
-
-    #[test]
-    fn data_u1() {
-        let mut data = Data {
-            data: vec![0xff, 0x00],
-            pointer: 0,
-        };
-        assert_eq!(data.u1().unwrap(), 0xff);
-        assert_eq!(data.u1().unwrap(), 0x00);
-        assert_eq!(data.last_u1().unwrap(), 0x00);
-    }
-
-    #[test]
-    fn data_u2() {
-        let mut data = Data {
-            data: vec![0xff, 0x33, 0x11, 0x00],
-            pointer: 0,
-        };
-        assert_eq!(data.u2().unwrap(), 0xff33);
-        assert_eq!(data.u2().unwrap(), 0x1100);
-        assert_eq!(data.last_u2().unwrap(), 0x1100);
-    }
-
-    #[test]
-    fn data_u4() {
-        let mut data = Data {
-            data: vec![0xff, 0x33, 0x11, 0x00],
-            pointer: 0,
-        };
-        assert_eq!(data.u4().unwrap(), 0xff331100);
-        assert_eq!(data.last_u4().unwrap(), 0xff331100);
-    }
-}

src/parse/model.rs

@@ -2,6 +2,7 @@
 //! The models for a .class file
 //!
 //! [The .class specs](https://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html)
+#![allow(dead_code)]
 
 // The types used in the specs
 #[allow(non_camel_case_types)]
@@ -14,7 +15,7 @@ pub type u4 = u32;
 ///
 /// # Represents a .class file
 ///
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct ClassFile {
     /// Magic number identifying the format (= 0xCAFEBABE)
     pub magic: u4,
@@ -53,7 +54,7 @@ pub struct ClassFile {
 /// A constant from the constant pool
 /// May have indices back to the constant pool, with expected types
 /// _index: A valid index into the `constant_pool` table.
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub enum CpInfo {
     Class {
         tag: u1, // 7
@@ -67,7 +68,7 @@ pub enum CpInfo {
         /// Entry must be `NameAndType`
         name_and_type_index: u2,
     },
-    Methodref {
+    MethodRef {
         tag: u1, // 10
         /// Must be a class type
         class_index: u2,
@@ -150,7 +151,7 @@ pub enum CpInfo {
 }
 
 /// Information about a field
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct FieldInfo {
     pub access_flags: u2,
     pub name_index: u2,
@@ -160,7 +161,7 @@ pub struct FieldInfo {
 }
 
 /// Information about a method
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct MethodInfo {
     /// Mask of `MethodAccessFlag` used to denote access permissions
     pub access_flags: u2,
@@ -175,7 +176,7 @@ pub struct MethodInfo {
 }
 
 /// See `AttributeInfo`
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct Attribute {
     pub attribute_name_index: u2,
     pub attribute_length: u4,
@@ -188,7 +189,7 @@ pub struct Attribute {
 /// `attribute_length`: The length of the subsequent bytes, does not include the first 6
 ///
 /// _index: Index to the `constant_pool` table of any type
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 #[allow(dead_code)] // todo yeah lol
 pub enum AttributeInfo {
     /// Only on fields, the constant value of that field
@@ -350,7 +351,7 @@ pub enum AttributeInfo {
 }
 
 /// An exception handler in the JVM bytecode array
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
 pub struct AttributeCodeException {
     /// The ranges in the code in which the handler is active. Must be a valid index into the code array.
     /// The `start_pc` is inclusive
@@ -367,7 +368,7 @@ pub struct AttributeCodeException {
 
 /// Specifies the type state at a particular bytecode offset
 /// Has a offset_delta, the offset is calculated by adding offset_delta + 1 to the previous offset
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub enum StackMapFrame {
     /// Exactly the same locals as the previous frame and zero stack items, offset_delta is frame_type
     SameFrame {
@@ -413,7 +414,7 @@ pub enum StackMapFrame {
 }
 
 /// A stack value/local variable type `StackMapFrame`
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
 pub enum VerificationTypeInfo {
     Top {
         tag: u1, // 0
@@ -448,7 +449,7 @@ pub enum VerificationTypeInfo {
 }
 
 /// A struct for the `AttributeInfo::InnerClasses`
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
 pub struct AttributeInnerClass {
     /// Must be a `Class`
     pub inner_class_info_index: u2,
@@ -461,7 +462,7 @@ pub struct AttributeInnerClass {
 }
 
 /// Line number information for `AttributeInfo::LineNumberTable`
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
 pub struct AttributeLineNumber {
     /// Index into the code array where a new line in the source begins
     pub start_pc: u2,
@@ -470,7 +471,7 @@ pub struct AttributeLineNumber {
 }
 
 /// Local variable information for `AttributeInfo::LocalVariableTable` and `AttributeInfo::LocalVariableTypeTable`
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
 pub struct AttributeLocalVariableTable {
     /// The local variable must have a value between `start_pc` and `start_pc + length`. Must be a valid opcode
     pub start_pc: u2,
@@ -485,7 +486,7 @@ pub struct AttributeLocalVariableTable {
 }
 
 /// A runtime-visible annotation to the program
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct Annotation {
     /// Must be `Utf8`
     pub type_index: u2,
@@ -496,7 +497,7 @@ pub struct Annotation {
 // these type names have just become java at this point. no shame.
 
 /// A element-value pair in the `Annotation`
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct AnnotationElementValuePair {
     /// Must be `Utf8`
     pub element_name_index: u2,
@@ -504,7 +505,7 @@ pub struct AnnotationElementValuePair {
 }
 
 /// The value of an `AnnotationElementValuePair`
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct AnnotationElementValue {
     /// B, C, D, F, I, J, S, Z or s, e, c, @,
     pub tag: u1,
@@ -512,7 +513,7 @@ pub struct AnnotationElementValue {
 }
 
 /// The value of a `AnnotationElementValue`
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub enum AnnotationElementValueValue {
     /// If the tag is B, C, D, F, I, J, S, Z, or s.
     ConstValueIndex {
@@ -544,14 +545,14 @@ pub enum AnnotationElementValueValue {
 }
 
 /// Used in `AttributeInfo::RuntimeVisibleParameterAnnotations`
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct ParameterAnnotation {
     pub num_annotations: u2,
     pub annotations: Vec<Annotation>,
 }
 
 /// Used in `AttributeInfo::BootstrapMethods `
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct BootstrapMethod {
     /// Must be a `MethodHandle`
     pub bootstrap_method_ref: u2,
@@ -564,7 +565,7 @@ pub struct BootstrapMethod {
 
 /// Access Flags of a class
 #[repr(u16)]
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
 pub enum ClassAccessFlag {
     /// Declared public; may be accessed from outside its package.
     Public = 0x0001,
@@ -586,7 +587,7 @@ pub enum ClassAccessFlag {
 
 /// Access Flags of a method
 #[repr(u16)]
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
 pub enum MethodAccessFlag {
     //	Declared public; may be accessed from outside its package.
     PUBLIC = 0x0001,
@@ -616,7 +617,7 @@ pub enum MethodAccessFlag {
 
 /// Access flags for an inner class
 #[repr(u16)]
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
 pub enum InnerClassAccessFlags {
     ///	Marked or implicitly public in source.
     PUBLIC = 0x0001,
@@ -642,7 +643,7 @@ pub enum InnerClassAccessFlags {
 
 /// Access flags for a field
 #[repr(u16)]
-#[derive(Debug, Clone, Hash)]
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
 pub enum FieldAccessFlags {
     ///	Declared public; may be accessed from outside its package.
     PUBLIC = 0x0001,

src/parse/test.rs

@@ -0,0 +1,125 @@
+use super::*;
+
+#[test]
+fn data_u1() {
+    let bytes = [0xff, 0x00];
+    let mut data = Data {
+        data: &bytes,
+        pointer: 0,
+    };
+    assert_eq!(data.u1().unwrap(), 0xff);
+    assert_eq!(data.u1().unwrap(), 0x00);
+    assert_eq!(data.last_u1().unwrap(), 0x00);
+}
+
+#[test]
+fn data_u2() {
+    let bytes = [0xff, 0x33, 0x11, 0x00];
+    let mut data = Data {
+        data: &bytes,
+        pointer: 0,
+    };
+    assert_eq!(data.u2().unwrap(), 0xff33);
+    assert_eq!(data.u2().unwrap(), 0x1100);
+    assert_eq!(data.last_u2().unwrap(), 0x1100);
+}
+
+#[test]
+fn data_u4() {
+    let bytes = [0xff, 0x33, 0x11, 0x00];
+    let mut data = Data {
+        data: &bytes,
+        pointer: 0,
+    };
+    assert_eq!(data.u4().unwrap(), 0xff331100);
+    assert_eq!(data.last_u4().unwrap(), 0xff331100);
+}
+
+#[test]
+fn parse_empty_class() {
+    let class = include_bytes!("../../testdata/Test.class");
+    println!("Starting test...");
+    let parsed = parse_class_file(class).unwrap();
+
+    assert_eq!(parsed.minor_version, 0);
+    assert_eq!(parsed.major_version, 0x003b);
+    assert_eq!(parsed.constant_pool_count, 0x000d);
+    assert_eq!(parsed.constant_pool.len(), 12);
+    assert_eq!(
+        parsed.constant_pool,
+        vec![
+            CpInfo::MethodRef {
+                tag: 0x0a,
+                class_index: 2,
+                name_and_type_index: 3
+            },
+            CpInfo::Class {
+                tag: 7,
+                name_index: 4
+            },
+            CpInfo::NameAndType {
+                tag: 0xc,
+                name_index: 5,
+                descriptor_index: 6
+            },
+            CpInfo::Utf8 {
+                tag: 1,
+                length: 0x10,
+                bytes: "java/lang/Object".bytes().collect()
+            },
+            CpInfo::Utf8 {
+                tag: 1,
+                length: 6,
+                bytes: "init".bytes().collect()
+            },
+            CpInfo::Utf8 {
+                tag: 1,
+                length: 3,
+                bytes: "()V".bytes().collect()
+            },
+            CpInfo::Class {
+                tag: 7,
+                name_index: 8
+            },
+            CpInfo::Utf8 {
+                tag: 1,
+                length: 4,
+                bytes: "Test".bytes().collect()
+            },
+            CpInfo::Utf8 {
+                tag: 1,
+                length: 4,
+                bytes: "Code".bytes().collect()
+            },
+            CpInfo::Utf8 {
+                tag: 1,
+                length: 15,
+                bytes: "LineNumberTable".bytes().collect()
+            },
+            CpInfo::Utf8 {
+                tag: 1,
+                length: 10,
+                bytes: "SourceFile".bytes().collect()
+            },
+            CpInfo::Utf8 {
+                tag: 1,
+                length: 9,
+                bytes: "Test.java".bytes().collect()
+            }
+        ]
+    );
+    assert_eq!(parsed.access_flags, 0x0021);
+    assert_eq!(parsed.this_class, 7);
+    assert_eq!(parsed.super_class, 2);
+    assert_eq!(parsed.interfaces_count, 0);
+    assert_eq!(parsed.interfaces, vec![]);
+    assert_eq!(parsed.fields_count, 0);
+    assert_eq!(parsed.fields, vec![]);
+    assert_eq!(parsed.method_count, 1);
+    assert_eq!(parsed.methods[0].access_flags, 1);
+    assert_eq!(parsed.methods[0].name_index, 5);
+    assert_eq!(parsed.methods[0].descriptor_index, 6);
+    assert_eq!(parsed.methods[0].attributes_count, 1);
+    assert_eq!(parsed.methods[0].attributes[0].attribute_name_index, 9);
+    assert_eq!(parsed.methods[0].attributes[0].attribute_length, 0x1d);
+}

testdata/Test.class.txt

@@ -0,0 +1,133 @@
+Manually parsed by hand
+
+hexdump -C Test.class
+
+00000000 |ca fe ba be|00 00|00 3b |00 0d|0a.00 02.00 03|07. |.......;........|
+00000010  00 04|0c.00 05.00 06|01 .00 10.6a 61 76 61 2f 6c  |..........java/l|
+00000020  61 6e 67 2f 4f 62 6a 65  63 74|01.00 06.3c 69 6e  |ang/Object...<in|
+00000030  69 74 3e|01.00 03.28 29  56|07.00 08|01.00 04.54  |it>...()V......T|
+00000040  65 73 74|01.00 04.43 6f  64 65|01.00 0f.4c 69 6e  |est...Code...Lin|
+00000050  65 4e 75 6d 62 65 72 54  61 62 6c 65|01.00 0a.53  |eNumberTable...S|
+00000060  6f 75 72 63 65 46 69 6c  65|01.00 09.54 65 73 74  |ourceFile...Test|
+00000070  2e 6a 61 76 61|00 21|00  07|00 02|00 00|00 00|00  |.java.!.........|
+00000080  01|00 01.00 05.00 06.00  01:00 09.00 00 00 1d.00  |................|
+00000090  01.00 01.00 00 00 05.2a  b7 00 01 b1.00 00.00 01: |.......*........|
+000000a0  00 0a.00 00 00 06.00 01 :00 00.00 01|00 01|00 0b. |................|
+000000b0  00 00 00 02.00 0c                                 |......|
+000000b6
+
+
+Magic: ca fe ba be
+Minor: 00 00
+Major: 00 3b
+CpCount: 00 0d (13) (13 - 1 = 12)
+Cp: [
+    1: {
+        tag: 0a (10, MethodRef)
+        class_index: 00 02 (2)
+        name_and_type_index: 00 03 (2)
+    }
+    2: {
+        tag: 07 (7, Class)
+        name_index: 00 04 (4) (java/lang/Object)
+    }
+    3: {
+        tag: 0c (12, NameAndType)
+        name_index: 00 05 (05)
+        descriptor_index: 00 06 (6)
+    }
+    4: {
+        tag: 01 (1, Utf8)
+        length: 00 10 (16)
+        string: 6a 61 76 61 2f 6c 61 6e 67 2f 4f 62 6a 65 63 74 (java/lang/Object)
+    }
+    5: {
+        tag: 01 (1, Utf8)
+        length: 00 06 (6)
+        string: 3c 69 6e 69 74 3e (<init>)
+    }
+    6: {
+        tag: 01 (1, Utf8)
+        length: 00 03 (3)
+        bytes: 28 29 56 (()V)
+    }
+    7: {
+        tag: 07 (7, Class)
+        name_index: 00 08 (8) (Test)
+    }
+    8: {
+        tag: 01 (1, Utf8)
+        length: 00 04 (4)
+        bytes: 54 65 73 74 (Test)
+    }
+    9: {
+        tag: 01 (1, Utf8)
+        length: 00 04 (4)
+        bytes: 43 6f 64 65 (Code)
+    }
+    10: {
+        tag: 01 (1, Utf8)
+        length: 00 0f (15)
+        bytes: 4c 69 6e 65 4e 75 6d 62 65 72 54 61 62 6c 65 (LineNumberTable)
+    }
+    11: {
+        tag: 01 (1, Utf8)
+        length: 00 0a (10)
+        bytes: 53 6f 75 72 63 65 46 69 6c 65 (SourceFile)
+    }
+    12: {
+        tag: 01 (1, Utf8)
+        length: 00 09 (9)
+        bytes: 54 65 73 74 2e 6a 61 76 61 (Test.java)
+    }
+]
+access_flags: 00 21
+this_class: 00 07 (Test)
+super_class: 00 02 (java/lang/Object)
+interfaces_count: 00 00
+interfaces: []
+fields_count: 00 00
+fields: []
+methods_count: 00 01
+methods: [
+    {
+        access_flags: 00 01
+        name_index: 00 05
+        descriptor_index: 00 06
+        attributes_count: 00 01
+        attributes: [
+            {
+                name_index: 00 09 (Code)
+                attribute_length: 00 00 00 1d (29)
+                max_stack: 00 01
+                max_locals: 00 01
+                code_length: 00 00 00 05
+                code: 2a b7 00 01 b1
+                exception_table_length: 00 00
+                exception_table: []
+                attributes_count: 00 01
+                attributes: [
+                    {
+                        attribute_name_index: 00 0a (LineNumberTable)
+                        attribute_length: 00 00 00 06
+                        line_number_table_length: 00 01
+                        line_number_table: [
+                            {
+                                start_pc: 00 00
+                                line_number: 00 01
+                            }
+                        ]
+                    }
+                ]
+            }
+        ]
+    }
+]
+attributes_count: 00 01
+attributes: [
+    {
+        attribute_name_index: 00 0b (SourceFile)
+        attribute_length: 00 00 00 02
+        sourcefile_index: 00 0c
+    }
+]

testdata/Test.java

@@ -0,0 +1 @@
+public class Test {}