Improve some tests and the contributing doc

CONTRIBUTING.md

@@ -5,8 +5,10 @@ Welcome! Thank you for taking an interest in contributing to Vineflower.
 * The [ARCHITECTURE.md](./ARCHITECTURE.md) file in the repository contains technical information on how Vineflower is structured. Reading that will greatly help with familiarizing yourself with the codebase and with PR development.
 * It's highly recommended to socialize your changes first through our [social platforms](https://github.com/Vineflower) before making a pull request!
 * Check out the issue tracker and roadmap! You can find good things to contribute there.
+* Make sure your pull request is based off of the latest development branch in the repository. The main branch is a stable snapshot, representing the latest released version of the decompiler.
 
 ## Good things to contribute
+* Fixes to bugs present in the decompiler.
 * Improvements to the readability of the decompiled code.
 * New feature support for the decompiler.
 * Optimization, to make it run faster and use fewer resources.
@@ -17,7 +19,7 @@ Welcome! Thank you for taking an interest in contributing to Vineflower.
 * More technical issues are usually found in the [Test class](https://github.com/Vineflower/vineflower/blob/master/test/org/jetbrains/java/decompiler/SingleClassesTest.java) where individual wrong tests are described with their errors.
 
 ## Code Style and guidelines
-While the code inherited from FernFlower varies with its style and syntax, it's expected that pull requests stick to our established code style.
+While the code inherited from Fernflower varies with its style and syntax, it's expected that pull requests stick to our established code style.
 * We use UpperCamelCase for class names, camelCase for method, variable, local variable, and field names, and UPPER_SNAKE_CASE for static final fields. Please always qualify instance fields with a `this.` qualifier.
 * Please try to keep pull requests small and self-contained! It makes reviewing and maintaining the patch much easier.
 * Statements should always have braces around them, even if they are only 1 line in their length.
@@ -30,12 +32,12 @@ While the code inherited from FernFlower varies with its style and syntax, it's
 * When contributing, you should add new tests that cover the area of code that you are targeting. Having more tests makes the decompiler more robust, so it's always appreciated.
 
 ## Resources
-FernFlower is a very complex and involved bit of software, and there's a lot going on in a rather questionable structure. Naturally, understanding it all is a challenge so various resources are provided here to aid with the process.
+Fernflower is a very complex and involved bit of software, and there's a lot going on in a rather questionable structure. Naturally, understanding it all is a challenge so various resources are provided here to aid with the process.
 * Knowing how java bytecode works is essential. You can find the detailed description of all the opcodes [here](https://docs.oracle.com/javase/specs/jvms/se16/html/jvms-6.html#jvms-6.5) or a simple list of them [here.](https://en.wikipedia.org/wiki/Java_bytecode_instruction_listings)
-* Graph theory comes up frequently in the statement analysis portion of FernFlower. It's useful knowing about [Basic Blocks](https://en.wikipedia.org/wiki/Basic_block), [Control Flow Graphs](https://en.wikipedia.org/wiki/Control-flow_graph), and [Dominators.](https://en.wikipedia.org/wiki/Dominator_(graph_theory))
+* Graph theory comes up frequently in the statement analysis portion of Fernflower. It's useful knowing about [Basic Blocks](https://en.wikipedia.org/wiki/Basic_block), [Control Flow Graphs](https://en.wikipedia.org/wiki/Control-flow_graph), and [Dominators.](https://en.wikipedia.org/wiki/Dominator_(graph_theory))
 * [Static Single Assignment Form](https://en.wikipedia.org/wiki/Static_single_assignment_form) is also used widely to track variables and their versions within the decompilation stages.
 * The [Java Language Specification](https://docs.oracle.com/javase/specs/jls/se16/html/), while dense, is a good source of information regarding language features.
-* The [ARCHITECTURE.md](./ARCHITECTURE.md) file in the repository contains important information about how FernFlower is structured.
+* The [ARCHITECTURE.md](./ARCHITECTURE.md) file in the repository contains important information about how Fernflower is structured.
 * The [social platforms](https://github.com/Vineflower) contains many people who have worked with the code before, so any remaining questions are best asked there.
 
 ## License

test/org/jetbrains/java/decompiler/SingleClassesTest.java

@@ -789,6 +789,8 @@ private void registerJavaRuntime() {
     register(JAVA_16_NODEBUG, "TestRecordCanonicalConstructor2");
     register(JAVA_8, "TestGenericArrays");
     register(JAVA_8, "TestInstanceGeneric");
+    // TODO: wrong cast in lambda for array
+    register(JAVA_8, "TestArrayGenerics");
   }
 
   private void registerLiterals() {

testData/results/pkg/TestArrayGenerics.dec

@@ -0,0 +1,59 @@
+package pkg;
+
+import java.lang.reflect.Array;
+import java.util.stream.IntStream;
+
+public class TestArrayGenerics {
+   private static <T> T[] myMethod(Object[] myObjects, Class<T> clazz) {
+      return (T[])IntStream.range(0, myObjects.length).mapToObj(i -> myObjects[i]).toArray(size -> (Object[])Array.newInstance(clazz, size));// 8 9 10
+   }
+}
+
+class 'pkg/TestArrayGenerics' {
+   method 'myMethod ([Ljava/lang/Object;Ljava/lang/Class;)[Ljava/lang/Object;' {
+      0      7
+      1      7
+      2      7
+      3      7
+      4      7
+      5      7
+      c      7
+      d      7
+      e      7
+      f      7
+      10      7
+      17      7
+      18      7
+      19      7
+      1a      7
+      1b      7
+      1c      7
+   }
+
+   method 'lambda$myMethod$0 ([Ljava/lang/Object;I)Ljava/lang/Object;' {
+      0      7
+      1      7
+      2      7
+      3      7
+   }
+
+   method 'lambda$myMethod$1 (Ljava/lang/Class;I)[Ljava/lang/Object;' {
+      0      7
+      1      7
+      2      7
+      3      7
+      4      7
+      5      7
+      6      7
+      7      7
+      8      7
+      9      7
+      a      7
+      b      7
+   }
+}
+
+Lines mapping:
+8 <-> 8
+9 <-> 8
+10 <-> 8

testData/results/pkg/TestItrLoop.dec

@@ -11,6 +11,24 @@ public class TestItrLoop {
          System.out.println(s);// 13
       }
    }// 15
+
+   public void test1() {
+      for (Object var2 : this.list) {// 18
+         ;
+      }
+   }// 21
+
+   public void test2() {
+      for (String var2 : this.list) {// 24
+         ;
+      }
+   }// 27
+
+   public void test3() {
+      for (String var2 : this.list) {// 30
+         ;
+      }
+   }// 33
 }
 
 class 'pkg/TestItrLoop' {
@@ -44,12 +62,90 @@ class 'pkg/TestItrLoop' {
       23      10
       27      12
    }
+
+   method 'test1 ()V' {
+      0      15
+      1      15
+      2      15
+      3      15
+      4      15
+      5      15
+      6      15
+      7      15
+      8      15
+      9      15
+      13      15
+      14      15
+      15      15
+      16      15
+      17      15
+      18      15
+      19      15
+      1d      18
+   }
+
+   method 'test2 ()V' {
+      0      21
+      1      21
+      2      21
+      3      21
+      4      21
+      5      21
+      6      21
+      7      21
+      8      21
+      9      21
+      13      21
+      14      21
+      15      21
+      16      21
+      17      21
+      18      21
+      19      21
+      1a      21
+      1b      21
+      1c      21
+      20      24
+   }
+
+   method 'test3 ()V' {
+      0      27
+      1      27
+      2      27
+      3      27
+      4      27
+      5      27
+      6      27
+      7      27
+      8      27
+      9      27
+      13      27
+      14      27
+      15      27
+      16      27
+      17      27
+      18      27
+      19      27
+      1a      27
+      1b      27
+      1c      27
+      20      30
+   }
 }
 
 Lines mapping:
 11 <-> 10
 12 <-> 10
 13 <-> 11
 15 <-> 13
+18 <-> 16
+21 <-> 19
+24 <-> 22
+27 <-> 25
+30 <-> 28
+33 <-> 31
 Not mapped:
 14
+20
+26
+32

testData/src/java8/pkg/TestArrayGenerics.java

@@ -0,0 +1,12 @@
+package pkg;
+
+import java.lang.reflect.Array;
+import java.util.stream.IntStream;
+
+public class TestArrayGenerics {
+  private static <T> T[] myMethod(Object[] myObjects, Class<T> clazz) {
+    return IntStream.range(0, myObjects.length)
+      .mapToObj(i -> myObjects[i])
+      .toArray(size -> (T[]) Array.newInstance(clazz, size));
+  }
+}

testData/src/java8/pkg/TestItrLoop.java

@@ -13,4 +13,22 @@ public void test() {
       System.out.println(s);
     }
   }
+
+  public void test1() {
+    for (Object o : list) {
+
+    }
+  }
+
+  public void test2() {
+    for (String s : (List<String>) list) {
+
+    }
+  }
+
+  public void test3() {
+    for (String s : (Iterable<String>) list) {
+
+    }
+  }
 }