Check call to function without effects has no effects

1 files changed, 24 insertions, 0 deletions

diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerCallTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerCallTests.java
index ad1ab07e..ffbc3c29 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerCallTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerCallTests.java
@@ -2,6 +2,9 @@ package org.shedlang.compiler.typechecker;
 
 import org.junit.jupiter.api.Test;
 import org.shedlang.compiler.ast.untyped.Untyped;
+import org.shedlang.compiler.ast.untyped.UntypedArgsNode;
+import org.shedlang.compiler.ast.untyped.UntypedCallNode;
+import org.shedlang.compiler.sources.Sources;
 import org.shedlang.compiler.typechecker.errors.*;
 import org.shedlang.compiler.typechecker.typesets.TypeSets;
 import org.shedlang.compiler.types.Effects;
@@ -274,4 +277,25 @@ public class TypeCheckerCallTests {
 
         assertThat(error.effect(), equalTo(Effects.IO));
     }
+
+    @Test
+    public void givenFunctionHasNoEffectWhenCallingFunctionWithExplicitEffectsThenErrorIsThrown() {
+        var untyped = new UntypedCallNode(
+            Untyped.reference("f"),
+            new UntypedArgsNode(List.of(), List.of(), Sources.NULL),
+            true,
+            Sources.NULL
+        );
+        var functionType = FunctionType.builder()
+            .withEffect(Effects.NONE)
+            .withReturnType(Types.UNIT)
+            .build();
+        var context = TypeCheckerContext.EMPTY
+            .enter(P.map(Map.entry("f", functionType)));
+
+        assertThrows(
+            FunctionHasNoEffectsError.class,
+            () -> TypeChecker.typeCheckExpression(untyped, context)
+        );
+    }
 }