Check that condition is a boolean

1 files changed, 11 insertions, 0 deletions

diff --git a/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java b/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java
index 3adea06..dbf20f8 100644
--- a/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java
@@ -3,7 +3,9 @@ package org.zwobble.couscous.tests.interpreter;
 import org.junit.Test;
 import org.zwobble.couscous.ast.FormalArgumentNode;
 import org.zwobble.couscous.ast.TernaryConditionalNode;
+import org.zwobble.couscous.interpreter.ConditionMustBeBoolean;
 import org.zwobble.couscous.interpreter.Environment;
+import org.zwobble.couscous.values.IntegerValue;
 import org.zwobble.couscous.values.StringValue;
 
 import com.google.common.collect.ImmutableMap;
@@ -12,6 +14,7 @@ import static org.junit.Assert.assertEquals;
 import static org.zwobble.couscous.ast.Assignment.assign;
 import static org.zwobble.couscous.ast.LiteralNode.literal;
 import static org.zwobble.couscous.interpreter.Evaluator.eval;
+import static org.zwobble.couscous.tests.util.ExtraAsserts.assertThrows;
 
 import lombok.val;
 
@@ -38,6 +41,14 @@ public class EvaluatorTests {
         assertEquals(new StringValue("F"), result);
     }
     
+    @Test
+    public void errorIfConditionIsNotBoolean() {
+        val exception = assertThrows(ConditionMustBeBoolean.class,
+            () -> eval(emptyEnvironment(),
+                new TernaryConditionalNode(literal(1), literal("T"), literal("F"))));
+        assertEquals(new ConditionMustBeBoolean(new IntegerValue(1)), exception);
+    }
+    
     private static Environment emptyEnvironment() {
         return new Environment(ImmutableMap.of());
     }