1 files changed, 123 insertions, 0 deletions
diff --git a/src/test/java/org/zwobble/couscous/tests/interpreter/InterpreterMethodTests.java b/src/test/java/org/zwobble/couscous/tests/interpreter/InterpreterMethodTests.java
new file mode 100644
index 0000000..26939dc
--- /dev/null
+++ b/src/test/java/org/zwobble/couscous/tests/interpreter/InterpreterMethodTests.java
@@ -0,0 +1,123 @@
+package org.zwobble.couscous.tests.interpreter;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.junit.Test;
+import org.zwobble.couscous.MapBackedProject;
+import org.zwobble.couscous.ast.AssignmentNode;
+import org.zwobble.couscous.ast.ClassNode;
+import org.zwobble.couscous.ast.ExpressionStatementNode;
+import org.zwobble.couscous.ast.LiteralNode;
+import org.zwobble.couscous.ast.ReturnNode;
+import org.zwobble.couscous.interpreter.Interpreter;
+import org.zwobble.couscous.interpreter.UnboundVariable;
+import org.zwobble.couscous.interpreter.UnexpectedValueType;
+import org.zwobble.couscous.interpreter.VariableNotInScope;
+import org.zwobble.couscous.interpreter.WrongNumberOfArguments;
+import org.zwobble.couscous.interpreter.values.ConcreteType;
+import org.zwobble.couscous.interpreter.values.InterpreterValues;
+import org.zwobble.couscous.tests.BackendMethodTests;
+import org.zwobble.couscous.tests.MethodRunner;
+import org.zwobble.couscous.values.IntegerValue;
+import org.zwobble.couscous.values.PrimitiveValue;
+import org.zwobble.couscous.values.StringValue;
+
+import com.google.common.collect.ImmutableMap;
+
+import static org.junit.Assert.assertEquals;
+import static org.zwobble.couscous.ast.FormalArgumentNode.formalArg;
+import static org.zwobble.couscous.ast.LiteralNode.literal;
+import static org.zwobble.couscous.ast.LocalVariableDeclarationNode.localVariableDeclaration;
+import static org.zwobble.couscous.ast.MethodNode.staticMethod;
+import static org.zwobble.couscous.ast.VariableDeclaration.var;
+import static org.zwobble.couscous.ast.VariableReferenceNode.reference;
+import static org.zwobble.couscous.tests.util.ExtraAsserts.assertThrows;
+import static org.zwobble.couscous.values.PrimitiveValues.value;
+
+import lombok.val;
+
+public class InterpreterMethodTests extends BackendMethodTests {
+    @Test
+    public void errorIfWrongNumberOfArgumentsArePassed() {
+        val method = staticMethod("hello");
+        
+        val exception = assertThrows(WrongNumberOfArguments.class,
+            () -> runMethod(method, value("hello, world!")));
+        
+        assertEquals(new WrongNumberOfArguments(0, 1), exception);
+    }
+    
+    @Test
+    public void errorIfTryingToAssignValueOfWrongTypeToVariable() {
+        val arg = formalArg(var(42, "x", StringValue.REF));
+        val method = staticMethod("hello")
+            .argument(arg)
+            .statement(new ExpressionStatementNode(new AssignmentNode(reference(arg), literal(0))));
+
+        val exception = assertThrows(UnexpectedValueType.class,
+            () -> runMethod(method, value("")));
+        
+        assertEquals(new UnexpectedValueType(StringValue.REF, IntegerValue.REF), exception);
+    }
+    
+    @Test
+    public void errorIfTryingToAssignToVariableNotInScope() {
+        val localVariableDeclaration = localVariableDeclaration(
+            42, "x", StringValue.REF, literal(""));
+        val method = staticMethod("hello")
+            .statement(new ExpressionStatementNode(new AssignmentNode(reference(localVariableDeclaration), LiteralNode.literal("[updated value]"))));
+
+        val exception = assertThrows(VariableNotInScope.class,
+            () -> runMethod(method));
+        
+        assertEquals(new VariableNotInScope(42), exception);
+    }
+    
+    @Test
+    public void errorIfTryingToGetValueOfVariableNotInScope() {
+        val localVariableDeclaration = localVariableDeclaration(
+            42, "x", StringValue.REF, literal(""));
+        val method = staticMethod("hello")
+            .statement(new ReturnNode(reference(localVariableDeclaration)));
+
+        val exception = assertThrows(VariableNotInScope.class,
+            () -> runMethod(method));
+        
+        assertEquals(new VariableNotInScope(42), exception);
+    }
+    
+    @Test
+    public void errorIfTryingToGetValueOfUnboundVariable() {
+        val localVariableDeclaration = localVariableDeclaration(
+            42, "x", StringValue.REF, literal(""));
+        val method = staticMethod("hello")
+            .statement(new ReturnNode(reference(localVariableDeclaration)))
+            .statement(localVariableDeclaration);
+
+        val exception = assertThrows(UnboundVariable.class,
+            () -> runMethod(method));
+        
+        assertEquals(new UnboundVariable(42), exception);
+    }
+
+    @Override
+    protected MethodRunner buildMethodRunner() {
+        return new MethodRunner() {
+            @Override
+            public PrimitiveValue runMethod(
+                    ClassNode classNode,
+                    String methodName,
+                    List<PrimitiveValue> arguments) {
+                val interpreter = new Interpreter(new MapBackedProject(ImmutableMap.of(
+                    classNode.getName(), ConcreteType.fromNode(classNode))));
+                val argumentValues = arguments.stream()
+                    .map(InterpreterValues::value)
+                    .collect(Collectors.toList());
+                
+                return interpreter.run(classNode.getName(), methodName, argumentValues)
+                    .toPrimitiveValue().get();
+            }
+        };
+    }
+}