aconfig: package fields must contain at least one dot char

Introduce a new requirement on package fields: a package must contain at
least one dot character.

Bug: 289336036
Test: atest aconfig.test
Change-Id: Idadcd2a76783a484cc5c6d6e94778c0248fa475f
diff --git a/tools/aconfig/src/codegen.rs b/tools/aconfig/src/codegen.rs
index fe52c8d..b7fb08f 100644
--- a/tools/aconfig/src/codegen.rs
+++ b/tools/aconfig/src/codegen.rs
@@ -32,6 +32,9 @@
 }
 
 pub fn is_valid_package_ident(s: &str) -> bool {
+    if !s.contains('.') {
+        return false;
+    }
     s.split('.').all(is_valid_name_ident)
 }
 
@@ -61,11 +64,12 @@
 
     #[test]
     fn test_is_valid_package_ident() {
-        assert!(is_valid_package_ident("foo"));
-        assert!(is_valid_package_ident("foo_bar_123"));
         assert!(is_valid_package_ident("foo.bar"));
+        assert!(is_valid_package_ident("foo.bar_baz"));
         assert!(is_valid_package_ident("foo.bar.a123"));
 
+        assert!(!is_valid_package_ident("foo_bar_123"));
+        assert!(!is_valid_package_ident("foo"));
         assert!(!is_valid_package_ident("foo._bar"));
         assert!(!is_valid_package_ident(""));
         assert!(!is_valid_package_ident("123_foo"));
@@ -75,6 +79,7 @@
         assert!(!is_valid_package_ident(".foo.bar"));
         assert!(!is_valid_package_ident("foo.bar."));
         assert!(!is_valid_package_ident("."));
+        assert!(!is_valid_package_ident(".."));
         assert!(!is_valid_package_ident("foo..bar"));
         assert!(!is_valid_package_ident("foo.__bar"));
     }