Tests for Enum#len

Bug: 117951873
Test: hidl_test
Change-Id: I532c983f72013446869e3c8e3bbc11c776bfcbfa
diff --git a/tests/expression/1.0/IExpression.hal b/tests/expression/1.0/IExpression.hal
index 2db9f61..36aed60 100644
--- a/tests/expression/1.0/IExpression.hal
+++ b/tests/expression/1.0/IExpression.hal
@@ -147,6 +147,28 @@
     logand4 = (0 && 1) == 0,
   };
 
+  // Tests for enum tags
+  enum NoElements : uint32_t {};
+  enum OneElement : uint32_t {A};
+  enum TwoElement : uint32_t {A,B};
+  enum TwoCollidingElements : uint32_t {A=1,B=1};
+  enum ThreeFromInheritance : TwoElement {C};
+  enum ThreeFromDoubleInheritance : ThreeFromInheritance {};
+  enum ThreeCollidingFromInheritance : TwoCollidingElements {C};
+
+  enum EnumTagTest : uint32_t {
+    a = NoElements#len == 0,
+    b = OneElement#len == 1,
+    c = TwoElement#len == 2,
+    d = TwoCollidingElements#len == 2,
+    e = ThreeFromInheritance#len == 3,
+    f = ThreeFromDoubleInheritance#len == 3,
+    g = ThreeCollidingFromInheritance#len == 3,
+
+    // fine to reference current enum as well
+    h = EnumTagTest#len == 8,
+  };
+
   enum Grayscale : int8_t {
     WHITE = 126,
     GRAY, // 127