Extract TypeCheckerSubtyping

1 files changed, 30 insertions, 0 deletions

diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerSubtypingTests.java b/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerSubtypingTests.java
new file mode 100644
index 0000000..35779fe
--- /dev/null
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerSubtypingTests.java
@@ -0,0 +1,30 @@
+package org.zwobble.hobgoblin.compiler.typechecker;
+
+import org.junit.jupiter.api.Test;
+import org.zwobble.hobgoblin.compiler.types.SimpleNativeType;
+
+import static org.zwobble.hobgoblin.compiler.typechecker.TypeCheckerSubtyping.isSubtype;
+import static org.zwobble.precisely.AssertThat.assertThat;
+import static org.zwobble.precisely.Matchers.equalTo;
+
+public class TypeCheckerSubtypingTests {
+    @Test
+    public void whenTypeIsEqualToTypeThenTypeIsSubtype() {
+        var nativeType1 = SimpleNativeType.builtin("Int32");
+        var nativeType2 = SimpleNativeType.builtin("Int32");
+
+        var isSubtype = isSubtype(nativeType1, nativeType2);
+
+        assertThat(isSubtype, equalTo(true));
+    }
+
+    @Test
+    public void distinctTypesAreNotSubtypes() {
+        var nativeType1 = SimpleNativeType.builtin("Int32");
+        var nativeType2 = SimpleNativeType.builtin("Int64");
+
+        var isSubtype = isSubtype(nativeType1, nativeType2);
+
+        assertThat(isSubtype, equalTo(false));
+    }
+}