Support int coercions on return

src/org/jetbrains/eval4j/interpreterLoop.kt

@@ -1,6 +1,5 @@
 package org.jetbrains.eval4j
 
-import org.objectweb.asm.tree.LabelNode
 import org.objectweb.asm.tree.AbstractInsnNode
 import org.objectweb.asm.tree.analysis.Frame
 import org.objectweb.asm.tree.MethodNode
@@ -95,7 +94,23 @@ fun interpreterLoop(
                     LOOKUPSWITCH -> UnsupportedByteCodeException("LOOKUPSWITCH is not supported yet")
                     TABLESWITCH -> UnsupportedByteCodeException("TABLESWITCH is not supported yet")
 
-                    IRETURN, LRETURN, FRETURN, DRETURN, ARETURN -> return ValueReturned(frame.getStack(0)!!)
+                    IRETURN, LRETURN, FRETURN, DRETURN, ARETURN -> {
+                        val value = frame.getStack(0)!!
+                        val expectedType = Type.getReturnType(m.desc)
+                        if (value.asmType != expectedType) {
+                            assert(insnOpcode == IRETURN, "Only ints should be coerced")
+
+                            val coerced = when (expectedType.getSort()) {
+                                Type.BOOLEAN -> boolean(value.boolean)
+                                Type.BYTE -> byte(value.int.toByte())
+                                Type.SHORT -> short(value.int.toShort())
+                                Type.CHAR -> char(value.int.toChar())
+                                else -> throw UnsupportedByteCodeException("Should not be coerced: $expectedType")
+                            }
+                            return ValueReturned(coerced)
+                        }
+                        return ValueReturned(value)
+                    }
                     RETURN -> return ValueReturned(VOID_VALUE)
                     IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IFNULL, IFNONNULL -> {
                         if (interpreter.checkUnaryCondition(frame.getStack(0)!!, insnOpcode)) {

src/org/jetbrains/eval4j/values.kt

@@ -69,12 +69,7 @@ fun obj<T>(v: T, t: Type = if (v != null) Type.getType(v.javaClass) else Type.ge
 
 val NULL_VALUE = ObjectValue(null, Type.getObjectType("null"))
 
-val Value.boolean: Boolean
-    get(): Boolean {
-        assert(this.asmType == Type.BOOLEAN_TYPE)
-        return (this as IntValue).value == 1
-    }
-
+val Value.boolean: Boolean get() = (this as IntValue).value == 1
 val Value.int: Int get() = (this as IntValue).value
 val Value.long: Long get() = (this as LongValue).value
 val Value.float: Float get() = (this as FloatValue).value

test/org/jetbrains/eval4j/test/TestData.java

@@ -1,9 +1,38 @@
 package org.jetbrains.eval4j.test;
 
 public class TestData {
-    public void imNotAPAckage() {}
+    public static void testReturnVoid() {
+    }
 
-    public static int testReturn() {
+    public static boolean testReturnBoolean() {
+        return true;
+    }
+
+    public static byte testReturnByte() {
         return 2;
     }
+
+    public static short testReturnShort() {
+        return 2;
+    }
+
+    public static char testReturnChar() {
+        return '2';
+    }
+
+    public static int testReturnInt() {
+        return 2;
+    }
+
+    public static long testReturnLong() {
+        return 2;
+    }
+
+    public static float testReturnFloat() {
+        return 2.0f;
+    }
+
+    public static double testReturnDouble() {
+        return 2.0d;
+    }
 }