Merge pull request #680 from github/rneatherway/example-query

Add an example query for inexhaustive switches

ql/examples/snippets/incompleteswitchoverenum.ql

@@ -0,0 +1,17 @@
+/**
+ * @name Incomplete switch over enum
+ * @description A switch statement of enum type should explicitly reference each
+ *   of the members of that enum.
+ * @kind problem
+ * @id go/examples/incomplete-switch
+ */
+
+import go
+
+from ExpressionSwitchStmt ss, DeclaredConstant c, NamedType t
+where
+  t.getUnderlyingType() instanceof IntegerType and
+  t = ss.getExpr().getType() and
+  c.getType() = t and
+  forall(CaseClause case | case = ss.getACase() | not case = c.getAReference().getParent())
+select ss, "This switch statement is not exhaustive: missing $@", c, c.getName()