test(classfile): enhance internal testing utility to test generated classes

JarvisCraft · JarvisCraft · commit b72b757f99b5 · 2020-12-24T23:23:53.000+03:00
diff --git a/javac-rs-classfile/src/bytecode.rs b/javac-rs-classfile/src/bytecode.rs
@@ -11,7 +11,6 @@ use crate::{
 };
 use std::cmp::max;
 
-use std::fs::read_to_string;
 use std::num::NonZeroU8;
 use thiserror::Error;
 
diff --git a/javac-rs-classfile/tests/class_testing.rs b/javac-rs-classfile/tests/class_testing.rs
@@ -1,14 +1,79 @@
-use javac_rs_classfile::{Class, ClassfileWritable};
+use std::error::Error;
+use std::ffi::OsStr;
 use std::fs::File;
+use std::io;
 use std::path::Path;
+use std::process::{Command, Output};
+
+use javac_rs_classfile::{Class, ClassfileWritable};
+
+// TODO consider using result instead of panicing
+
+pub type Result<T> = std::result::Result<T, Box<dyn Error>>;
 
-pub fn dump_class<P: AsRef<Path>>(class: Class, file: P) {
-    let path = file.as_ref();
+pub struct ClassTester {
+    class_name: String,
+}
+
+impl ClassTester {
+    pub fn run(&self) -> Result<Output> {
+        Ok(Command::new("java").arg(&self.class_name).output()?)
+    }
+
+    pub fn run_with_args<I: IntoIterator<Item=S>, S: AsRef<OsStr>>(
+        &self,
+        args: I,
+    ) -> io::Result<Output> {
+        Command::new("java")
+            .args(args)
+            .arg(&self.class_name)
+            .output()
+    }
+
+    pub fn disasm(&self) -> io::Result<Output> {
+        Command::new("javap").arg(&self.class_name).output()
+    }
+
+    pub fn disasm_with_args<I: IntoIterator<Item=S>, S: AsRef<OsStr>>(
+        &self,
+        args: I,
+    ) -> io::Result<Output> {
+        Command::new("javap")
+            .args(args)
+            .arg(&self.class_name)
+            .output()
+    }
+
+    pub fn assert_disasmable(&self) {
+        let result = self
+            .disasm()
+            .expect(&format!("Cannot execute javap for {}", self.class_name));
+        assert_eq!(
+            result
+                .status
+                .code()
+                .expect("Class disassembly was terminated by a signal"),
+            0,
+            "Class could not be disassembled{}",
+            String::from_utf8(result.stdout).map_or("".to_string(), |error| {
+                let mut out = ": ".to_string();
+                out.push_str(&error);
+                out
+            })
+        )
+    }
+}
+
+pub fn dump_class(class: Class, class_name: String) -> Result<ClassTester> {
+    let mut path = class_name.clone().replace('.', "/");
+    path.push_str(".class");
+    let path = Path::new(&path);
     if let Some(parent) = path.parent() {
-        std::fs::create_dir_all(parent).expect("Could not create parent directory");
+        std::fs::create_dir_all(parent)?;
     }
-    let mut file = File::create(path).expect("Could not create file from path");
+    let mut file = File::create(path)?;
 
-    println!("Writing class:\n{:#?}\nto file{:#?}", class, file);
     class.write_to_classfile(&mut file);
+
+    Ok(ClassTester { class_name })
 }
diff --git a/javac-rs-classfile/tests/class_with_attributes.rs b/javac-rs-classfile/tests/class_with_attributes.rs
@@ -1,7 +1,10 @@
-use javac_rs_classfile::*;
 use std::convert::TryFrom;
 use std::fs::File;
 
+use javac_rs_classfile::*;
+
+mod class_testing;
+
 #[test]
 fn class_file_with_source_file_attribute() {
     let mut class = Class::new(
@@ -17,11 +20,12 @@ fn class_file_with_source_file_attribute() {
         .unwrap();
     let class = class;
 
-    let mut file =
-        File::create("ru/progrm_jarvis/javacrs/TestClassWithSourceFileAttribute.class").unwrap();
-    println!("{:#?}", class);
-    class.write_to_classfile(&mut file);
-    println!("Written to file: {:#?}", file);
+    class_testing::dump_class(
+        class,
+        "ru.progrm_jarvis.javacrs.TestClassWithSourceFileAttribute".to_string(),
+    )
+        .unwrap()
+        .assert_disasmable();
 }
 
 #[test]
@@ -35,11 +39,12 @@ fn class_file_with_synthetic_attribute() {
     class.add_synthetic_attribute().unwrap();
     let class = class;
 
-    let mut file =
-        File::create("ru/progrm_jarvis/javacrs/TestClassWithSyntheticAttribute.class").unwrap();
-    println!("{:#?}", class);
-    class.write_to_classfile(&mut file);
-    println!("Written to file: {:#?}", file);
+    class_testing::dump_class(
+        class,
+        "ru.progrm_jarvis.javacrs.TestClassWithSyntheticAttribute".to_string(),
+    )
+        .unwrap()
+        .assert_disasmable();
 }
 
 #[test]
@@ -53,11 +58,12 @@ fn class_file_with_deprecated_attribute() {
     class.add_deprecated_attribute().unwrap();
     let class = class;
 
-    let mut file =
-        File::create("ru/progrm_jarvis/javacrs/TestClassWithDeprecatedAttribute.class").unwrap();
-    println!("{:#?}", class);
-    class.write_to_classfile(&mut file);
-    println!("Written to file: {:#?}", file);
+    class_testing::dump_class(
+        class,
+        "ru.progrm_jarvis.javacrs.TestClassWithDeprecatedAttribute".to_string(),
+    )
+        .unwrap()
+        .assert_disasmable();
 }
 
 #[test]
@@ -73,11 +79,12 @@ fn class_file_with_signature_attribute() {
         .unwrap();
     let class = class;
 
-    let mut file =
-        File::create("ru/progrm_jarvis/javacrs/TestClassWithSignatureAttribute.class").unwrap();
-    println!("{:#?}", class);
-    class.write_to_classfile(&mut file);
-    println!("Written to file: {:#?}", file);
+    class_testing::dump_class(
+        class,
+        "ru.progrm_jarvis.javacrs.TestClassWithSignatureAttribute".to_string(),
+    )
+        .unwrap()
+        .assert_disasmable();
 }
 
 #[test]
@@ -96,11 +103,12 @@ fn class_file_with_single_custom_attribute() {
         .unwrap();
     let class = class;
 
-    let mut file =
-        File::create("ru/progrm_jarvis/javacrs/TestClassWithSingleCustomAttribute.class").unwrap();
-    println!("{:#?}", class);
-    class.write_to_classfile(&mut file);
-    println!("Written to file: {:#?}", file);
+    class_testing::dump_class(
+        class,
+        "ru.progrm_jarvis.javacrs.TestClassWithSingleCustomAttribute".to_string(),
+    )
+        .unwrap()
+        .assert_disasmable();
 }
 
 #[test]
@@ -125,10 +133,10 @@ fn class_file_with_multiple_custom_attributes() {
         .unwrap();
     let class = class;
 
-    let mut file =
-        File::create("ru/progrm_jarvis/javacrs/TestClassWithMultipleCustomAttributes.class")
-            .unwrap();
-    println!("{:#?}", class);
-    class.write_to_classfile(&mut file);
-    println!("Written to file: {:#?}", file);
+    class_testing::dump_class(
+        class,
+        "ru.progrm_jarvis.javacrs.TestClassWithMultipleCustomAttributes".to_string(),
+    )
+        .unwrap()
+        .assert_disasmable();
 }
diff --git a/javac-rs-classfile/tests/class_with_fields.rs b/javac-rs-classfile/tests/class_with_fields.rs
@@ -1,10 +1,13 @@
-use javac_rs_classfile::{
-    major_versions, Class, ClassAccessFlag, ClassfileVersion, ClassfileWritable, ConstValue,
-    FieldAccessFlag, FieldDescriptor, JvmVecU4,
-};
 use std::convert::TryFrom;
 use std::fs::File;
 
+use javac_rs_classfile::{
+    Class, ClassAccessFlag, ClassfileVersion, ClassfileWritable, ConstValue, FieldAccessFlag,
+    FieldDescriptor, JvmVecU4, major_versions,
+};
+
+mod class_testing;
+
 #[test]
 fn class_file_with_field_without_attributes() {
     let mut class = Class::new(
@@ -23,12 +26,14 @@ fn class_file_with_field_without_attributes() {
             FieldDescriptor::Int,
         )
         .unwrap();
+    let class = class;
 
-    let mut file =
-        File::create("ru/progrm_jarvis/javacrs/TestClassWithFieldWithoutAttributes.class").unwrap();
-    println!("{:#?}", class);
-    class.write_to_classfile(&mut file);
-    println!("Written to file: {:#?}", file);
+    class_testing::dump_class(
+        class,
+        "ru.progrm_jarvis.javacrs.TestClassWithFieldWithoutAttributes".to_string(),
+    )
+        .unwrap()
+        .assert_disasmable();
 }
 
 #[test]
@@ -52,12 +57,14 @@ fn class_file_with_field_with_const_value_attribute() {
             .unwrap();
         class.field_add_const_value_attribute(field, ConstValue::Integer(123));
     }
+    let class = class;
 
-    let mut file =
-        File::create("ru/progrm_jarvis/javacrs/TestClassWithConstValueAttribute.class").unwrap();
-    println!("{:#?}", class);
-    class.write_to_classfile(&mut file);
-    println!("Written to file: {:#?}", file);
+    class_testing::dump_class(
+        class,
+        "ru.progrm_jarvis.javacrs.TestClassWithConstValueAttribute".to_string(),
+    )
+        .unwrap()
+        .assert_disasmable();
 }
 
 #[test]
@@ -97,10 +104,12 @@ fn class_file_with_field_with_various_attributes() {
             )
             .unwrap();
     }
+    let class = class;
 
-    let mut file =
-        File::create("ru/progrm_jarvis/javacrs/TestClassWithVariousAttributes.class").unwrap();
-    println!("{:#?}", class);
-    class.write_to_classfile(&mut file);
-    println!("Written to file: {:#?}", file);
+    class_testing::dump_class(
+        class,
+        "ru.progrm_jarvis.javacrs.TestClassWithVariousAttributes".to_string(),
+    )
+        .unwrap()
+        .assert_disasmable();
 }
diff --git a/javac-rs-classfile/tests/class_with_methods.rs b/javac-rs-classfile/tests/class_with_methods.rs
@@ -1,9 +1,8 @@
+use std::convert::TryFrom;
+
 use javac_rs_classfile::{
-    major_versions, Bytecode, Class, ClassAccessFlag, ClassfileVersion, ClassfileWritable,
-    ConstValue, JvmVecU4, MethodAccessFlag,
+    Bytecode, Class, ClassAccessFlag, ClassfileVersion, JvmVecU4, major_versions, MethodAccessFlag,
 };
-use std::convert::TryFrom;
-use std::fs::File;
 
 mod class_testing;
 
@@ -28,8 +27,8 @@ fn class_file_with_method_without_attributes() {
 
     class_testing::dump_class(
         class,
-        "ru/progrm_jarvis/javacrs/TestClassWithMethodWithoutAttributes.class",
-    );
+        "ru.progrm_jarvis.javacrs.TestClassWithMethodWithoutAttributes".to_string(),
+    ).unwrap().run();
 }
 
 #[test]
@@ -68,11 +67,12 @@ fn class_file_with_method_with_various_attributes() {
             )
             .unwrap();
     }
+    let class = class;
 
     class_testing::dump_class(
         class,
-        "ru/progrm_jarvis/javacrs/TestClassWithVariousAttributes.class",
-    );
+        "ru.progrm_jarvis.javacrs.TestClassWithVariousAttributes".to_string(),
+    ).unwrap().assert_disasmable();
 }
 
 #[test]
@@ -100,11 +100,12 @@ fn class_file_with_method_with_code_attribute() {
         println!("Bytecode: {:?}", bytecode);
         class.method_add_code_attribute(method, bytecode);
     }
+    let class = class;
 
     class_testing::dump_class(
         class,
-        "ru/progrm_jarvis/javacrs/TestClassWithCodeAttribute.class",
-    );
+        "ru.progrm_jarvis.javacrs.TestClassWithCodeAttribute".to_string(),
+    ).unwrap().assert_disasmable();
 }
 
 #[test]
@@ -171,11 +172,17 @@ fn class_file_with_hello_world_main_method() {
 
         class.method_add_code_attribute(method, bytecode).unwrap();
     }
+    let class = class;
 
-    class_testing::dump_class(
+    let result = class_testing::dump_class(
         class,
-        "ru/progrm_jarvis/javacrs/ClassWithHelloWorldMainMethod.class",
-    );
+        "ru.progrm_jarvis.javacrs.ClassWithHelloWorldMainMethod".to_string(),
+    )
+        .unwrap()
+        .run()
+        .unwrap();
+    assert_eq!(result.status.code().expect("Process terminated with signal"), 0);
+    assert_eq!(result.stdout, b"Hello world!\n");
 }
 
 // currently stack frame attributes are not set thus the class should be run using `-noverify`
@@ -249,9 +256,30 @@ fn class_file_with_naive_loop_in_main_method() {
 
         class.method_add_code_attribute(method, bytecode).unwrap();
     }
+    let class = class;
 
-    class_testing::dump_class(
+    let result = class_testing::dump_class(
         class,
-        "ru/progrm_jarvis/javacrs/ClassWithNaiveLoopInMainMethod.class",
+        "ru.progrm_jarvis.javacrs.ClassWithNaiveLoopInMainMethod".to_string(),
+    )
+        .unwrap()
+        .run_with_args(&["-noverify"])
+        .unwrap();
+    assert_eq!(
+        result
+            .status
+            .code()
+            .expect("Process terminated with signal"),
+        0
+    );
+    assert_eq!(
+        result.stdout,
+        b"5\n\
+        4\n\
+        3\n\
+        2\n\
+        1\n\
+        0\n\
+        "
     );
 }
diff --git a/javac-rs-classfile/tests/simple_class.rs b/javac-rs-classfile/tests/simple_class.rs
