Calculate target_rule_type_name correctly

Summary: When we have a transition on a rule, we want the `target_rule_type_name` to be the actual rule type, rather than always just being `"forward"`.

Reviewed By: JakobDegen

Differential Revision: D66312159

fbshipit-source-id: aa6a0c1475b97c5d1928a8dd278973990237a3b2

app/buck2_build_api/src/actions/calculation.rs

@@ -633,7 +633,7 @@ pub async fn get_target_rule_type_name(
         .get_configured_target_node(label)
         .await?
         .require_compatible()?
-        .rule_type()
+        .underlying_rule_type()
         .name()
         .to_owned())
 }

app/buck2_node/src/nodes/configured.rs

@@ -119,6 +119,13 @@ impl TargetNodeOrForward {
         }
     }
 
+    fn underlying_rule_type(&self) -> &RuleType {
+        match self {
+            TargetNodeOrForward::TargetNode(target_node) => target_node.rule_type(),
+            TargetNodeOrForward::Forward(_, node) => node.underlying_rule_type(),
+        }
+    }
+
     fn rule_kind(&self) -> RuleKind {
         match self {
             TargetNodeOrForward::TargetNode(x) => x.rule_kind(),
@@ -433,6 +440,10 @@ impl ConfiguredTargetNode {
         self.0.target_node.rule_type()
     }
 
+    pub fn underlying_rule_type(&self) -> &RuleType {
+        self.0.target_node.underlying_rule_type()
+    }
+
     pub fn rule_kind(&self) -> RuleKind {
         self.0.target_node.rule_kind()
     }

tests/core/build/test_build_rule_type_name_logging.py

@@ -63,8 +63,7 @@ async def test_build_rule_with_transition(buck: Buck) -> None:
         "//:a_writer_with_transition",
     )
 
-    # TODO(T208425986) This should not be "forward"
-    await check_rule_type_names(buck, ["forward"])
+    await check_rule_type_names(buck, ["three_with_transition"])
 
 
 @buck_test()
@@ -76,7 +75,7 @@ async def test_build_all_in_target(buck: Buck) -> None:
         buck,
         [
             "two",
-            "forward",
+            "three_with_transition",
             "nested_subtargets",
             "one",
             "one",
@@ -94,7 +93,7 @@ async def test_build_all_recursive(buck: Buck) -> None:
         buck,
         [
             "two",
-            "forward",
+            "three_with_transition",
             "nested_subtargets",
             "one",
             "one",