Introduce effect arg

1 files changed, 12 insertions, 0 deletions

diff --git a/src/test/java/org/shedlang/compiler/types/TypeSubstitutionTests.java b/src/test/java/org/shedlang/compiler/types/TypeSubstitutionTests.java
index 37341a7a..c85087fd 100644
--- a/src/test/java/org/shedlang/compiler/types/TypeSubstitutionTests.java
+++ b/src/test/java/org/shedlang/compiler/types/TypeSubstitutionTests.java
@@ -14,6 +14,18 @@ public class TypeSubstitutionTests {
     private static final SimpleStructType STRUCT_TYPE_2 = Types.struct(NAMESPACE_NAME, "Struct2");
 
     @Test
+    public void substitutingEffectArgDoesNothing() {
+        var effectParam = EffectParam.forStructType(STRUCT_TYPE, "E");
+        var typeSubstitutionMap = TypeSubstitutionMap.of(
+            Map.entry(effectParam, Effects.NONE)
+        );
+
+        var result = TypeSubstitution.substituteEffect(new EffectArg(effectParam), typeSubstitutionMap);
+
+        assertThat(result, equalTo(new EffectArg(effectParam)));
+    }
+
+    @Test
     public void substitutingEffectParamDoesNothingIfEffectParamIsNotInSubstitutionMap() {
         var typeSubstitutionMap = TypeSubstitutionMap.of(
             Map.entry(EffectParam.forStructType(STRUCT_TYPE, "E"), Effects.IO)