Add an explanation for WrongOneOf

PiperOrigin-RevId: 443398259
google · Apr 21, 2022 · 330375e · 330375e
1 parent bfd9b1d
commit 330375e
Showing 1 changed file with 11 additions and 0 deletions.
diff --git a/docs/bugpattern/WrongOneof.md b/docs/bugpattern/WrongOneof.md
@@ -0,0 +1,11 @@
+When switching over a proto `one_of`, getters that don't match the current case
+are guaranteed to be return a default instance:
+
+```java
+switch (foo.getBlahCase()) {
+  case FOO:
+    return foo.getFoo();
+  case BAR:
+    return foo.getFoo(); // should be foo.getBar()
+}
+```