Fix sorting of examples with global priority. (#54)

src/help-generator_.toit

@@ -322,7 +322,8 @@ class HelpGenerator:
     this-examples := command_.examples_.map: | example/Example | [example, path_]
     sub-examples := []
     add-global-examples_ command_ sub-examples --path=path_ --skip-first-level
-    sub-examples.sort --in-place: | a/List b/List | a[0].global-priority - b[0].global-priority
+    // Higher priority examples should come first.
+    sub-examples.sort --in-place: | a/List b/List | b[0].global-priority.compare-to a[0].global-priority
 
     all-examples := this-examples + sub-examples
     if all-examples.is-empty: return

tests/help_test.toit

@@ -769,17 +769,17 @@ test-examples:
       # Root example 2:
       root sub2
 
+      # Example 5:
+      root sub2 global5
+
+      # Example 1:
+      root sub global3
+
       # Example 3:
       root sub global1
 
       # Example 6:
       root sub2 global1
-
-      # Example 1:
-      root sub global3
-
-      # Example 5:
-      root sub2 global5
     """
   actual = build-examples.call [cmd]
   expect-equals expected actual