Rust: improve modules test case

Author: aibaars

rust/ql/test/extractor-tests/crate_graph/modules.expected

@@ -2,8 +2,6 @@
 
 #-----| fn length
 
-#-----| fn write
-
 #-----| fn as_string
 
 #-----| fn fmt
@@ -13,15 +11,14 @@
 #-----| Static
 
 #-----| mod module
+#-----|  -> Const
+#-----|  -> Static
+#-----|  -> enum X
 #-----|  -> fn length
-#-----|  -> fn write
+#-----|  -> impl ...::Display for ...::X { ... }
+#-----|  -> impl AsString for ...::X { ... }
 #-----|  -> struct X_List
-#-----|  -> Static
 #-----|  -> trait AsString
-#-----|  -> Const
-#-----|  -> impl AsString for ...::X { ... }
-#-----|  -> impl ...::Display for ...::X { ... }
-#-----|  -> enum X
 
 #-----| mod crate
 #-----|  -> mod module

rust/ql/test/extractor-tests/crate_graph/modules.ql

@@ -6,12 +6,30 @@
 
 import rust
 
-query predicate nodes(Item i) {
-  i.getParentNode*() = any(Crate m | m.getName() = "test" and m.getVersion() = "0.0.1").getModule()
+query predicate nodes(Item i) { i instanceof RelevantNode }
+
+class RelevantNode extends Item {
+  RelevantNode() {
+    this.getParentNode*() =
+      any(Crate m | m.getName() = "test" and m.getVersion() = "0.0.1").getModule()
+  }
 }
 
-query predicate edges(Item container, Item element) {
+predicate edges(RelevantNode container, RelevantNode element) {
   element = container.(Module).getItemList().getAnItem() or
   element = container.(Impl).getAssocItemList().getAnAssocItem() or
   element = container.(Trait).getAssocItemList().getAnAssocItem()
 }
+
+query predicate edges(RelevantNode pred, RelevantNode succ, string attr, string val) {
+  edges(pred, succ) and
+  (
+    attr = "semmle.label" and
+    val = ""
+    or
+    attr = "semmle.order" and
+    val =
+      any(int i | succ = rank[i](Item s, Location l | edges(pred, s) | s order by s.toString()))
+          .toString()
+  )
+}