witx: add a multimodule test that rejects redefined names

and rename the path to be a litle shorter

tools/witx/tests/simple_multimodule.rs → tools/witx/tests/multimodule.rs

@@ -1,13 +1,13 @@
 use witx::{load, BuiltinType, DatatypeIdent, DatatypeVariant, Id};
 
 #[test]
-fn validate_simple_multimodule() {
+fn validate_multimodule() {
     // B uses A, and C uses A.
     let doc = load(&[
-        "tests/simple_multimodule/type_b.witx",
-        "tests/simple_multimodule/type_c.witx",
+        "tests/multimodule/type_b.witx",
+        "tests/multimodule/type_c.witx",
     ])
-    .unwrap_or_else(|e| panic!("failed to parse: {}", e));
+    .unwrap_or_else(|e| panic!("failed to validate: {}", e));
 
     println!("{}", doc);
 
@@ -51,3 +51,12 @@ fn validate_simple_multimodule() {
         _ => panic!("c is a struct"),
     }
 }
+
+#[test]
+fn multimodule_reject_redefinition() {
+    assert!(load(&[
+        "tests/multimodule/type_a.witx",
+        "tests/multimodule/redefine_a.witx",
+    ])
+    .is_err())
+}

tools/witx/tests/multimodule/redefine_a.witx

@@ -0,0 +1 @@
+(typename $a u8)