New Mojom parser: Don't allow enum variables to be assigned int values.

mojom/mojom_parser/parser/resolution_test.go

Index: mojom/mojom_parser/parser/resolution_test.go
diff --git a/mojom/mojom_parser/parser/resolution_test.go b/mojom/mojom_parser/parser/resolution_test.go
index 57c0cb92e2e380f50e6326c5cebc6285c42d050a..1025231f632d1f7a4088ba91d9d68518bf98e877 100644
--- a/mojom/mojom_parser/parser/resolution_test.go
+++ b/mojom/mojom_parser/parser/resolution_test.go
@@ -642,6 +642,10 @@ func TestSingleFileTypeValidationErrors(t *testing.T) {
 	test := singleFileTest{}
 
 	////////////////////////////////////////////////////////////
+	// Group 1: Left-hand-side is a struct
+	////////////////////////////////////////////////////////////
+
+	////////////////////////////////////////////////////////////
 	// Test Case: Use struct as constant type
 	////////////////////////////////////////////////////////////
 	{
@@ -657,7 +661,7 @@ func TestSingleFileTypeValidationErrors(t *testing.T) {
 	}
 
 	////////////////////////////////////////////////////////////
-	// Test Case: Assign struct as map key
+	// Test Case: Use struct as map key
 	////////////////////////////////////////////////////////////
 	{
 		contents := `
@@ -691,6 +695,46 @@ func TestSingleFileTypeValidationErrors(t *testing.T) {
 	}
 
 	////////////////////////////////////////////////////////////
+	// Group 2: Left-hand-side is an enum
+	////////////////////////////////////////////////////////////
+
+	////////////////////////////////////////////////////////////
+	// Test Case: Assign an integer to an enum variable in a struct field.
+	////////////////////////////////////////////////////////////
+	{
+		contents := `
+	enum Hats {
+		COWBOY,
+		TOP
+	};
+
+    struct Bar{
+    	Hats my_hat = 1;
+    };
+	`
+		test.addTestCase(contents, []string{
+			"Illegal assignment",
+			"Field my_hat of type Hats may not be assigned the value 1 of type int8."})
+	}
+
+	////////////////////////////////////////////////////////////
+	// Test Case: Assign an integer to an enum variable in a constant.
+	////////////////////////////////////////////////////////////
+	{
+		contents := `
+	enum Hats {
+		COWBOY,
+		TOP
+	};
+
+    const Hats MY_HAT = 1;
+	`
+		test.addTestCase(contents, []string{
+			"Illegal assignment",
+			"Const MY_HAT of type Hats may not be assigned the value 1 of type int8."})
+	}
+
+	////////////////////////////////////////////////////////////
 	// Execute all of the test cases.
 	////////////////////////////////////////////////////////////
 	for i, c := range test.cases {