Clarify `@DoNotMock` error message in ClassInstrumentor

Robolectric's ClassInstrumentor adds a @DoNotMock annotation to Android classes
that originally contained the 'final' modifier.

The warning message always suggested to create or enhance a Shadow for the
Android class being instrumented. However, there are cases when it is
preferable to create a Builder, such as when the class is a pure Java data
class.

Update the `@DoNotMock` message to include this nuance.

Note that this @DoNotMock annotation is purely informative and requires special
infrastructure to enforce, so it's not on by default for Gradle/third-party
projects.

PiperOrigin-RevId: 625720769

1 files changed, 5 insertions, 2 deletions

diff --git a/sandbox/src/main/java/org/robolectric/internal/bytecode/ClassInstrumentor.java b/sandbox/src/main/java/org/robolectric/internal/bytecode/ClassInstrumentor.java
index a9b532a26..9d3d51af9 100644
--- a/sandbox/src/main/java/org/robolectric/internal/bytecode/ClassInstrumentor.java
+++ b/sandbox/src/main/java/org/robolectric/internal/bytecode/ClassInstrumentor.java
@@ -177,8 +177,11 @@ public class ClassInstrumentor {
               .visitAnnotation("Lcom/google/errorprone/annotations/DoNotMock;", true)
               .visit(
                   "value",
-                  "This class is final. Consider using the real thing, or "
-                      + "adding/enhancing a Robolectric shadow for it.");
+                  "This class is final. Consider either:\n"
+                      + "1. Using the real class.\n"
+                      + "2. If it's a pure data class, adding a Robolectric Builder for it.\n"
+                      + "3. If it cannot function on the JVM, adding or enhancing a Robolectric"
+                      + " Shadow for it");
         }
         mutableClass.classNode.access = mutableClass.classNode.access & ~Opcodes.ACC_FINAL;