Add logging of applied adjust rules

tmt/base.py

@@ -331,6 +331,32 @@ def _export(
     )
 
 
+def create_adjust_callback(logger: tmt.log.Logger) -> fmf.base.AdjustCallback:
+    """
+    Create a custom callback for fmf's adjust.
+
+    Given the ``adjust`` rules are applied on many places, for
+    proper logging they need their own specific logger. Create
+    a callback closure with the given logger.
+    """
+
+    def callback(
+            node: fmf.Tree,
+            rule: _RawAdjustRule,
+            applied: bool) -> None:
+        if applied is False:
+            return
+
+        logger.verbose(
+            f"Adjust rule applied to '{node.name}'",
+            tmt.utils.format_value(rule, key_color='green'),
+            color='cyan',
+            level=3,
+            topic=tmt.log.Topic.ADJUST_RULINGS)
+
+    return callback
+
+
 # Types describing content accepted by various require-like keys: strings, fmf ids,
 # paths, or lists mixing various types.
 #
@@ -2587,7 +2613,9 @@ def tree(self) -> fmf.Tree:
             except fmf.utils.FileError as error:
                 raise tmt.utils.GeneralError(f"Invalid yaml syntax: {error}")
             # Adjust metadata for current fmf context
-            self._tree.adjust(fmf.context.Context(**self._fmf_context))
+            self._tree.adjust(
+                fmf.context.Context(**self._fmf_context),
+                on_rule=create_adjust_callback(self._logger))
         return self._tree
 
     @tree.setter
@@ -3876,7 +3904,9 @@ def resolve_dynamic_ref(
     reference_tree = fmf.Tree(data=data)
     if not plan:
         raise tmt.utils.FileError("Cannot get plan fmf context to evaluate dynamic ref.")
-    reference_tree.adjust(fmf.context.Context(**plan._fmf_context))
+    reference_tree.adjust(
+        fmf.context.Context(**plan._fmf_context),
+        on_rule=create_adjust_callback(logger))
     # Also temporarily build a plan so that env and context variables are expanded
     Plan(logger=logger, node=reference_tree, run=plan.my_run, skip_validation=True)
     ref = reference_tree.get("ref")

tmt/log.py

@@ -51,6 +51,7 @@
 class Topic(enum.Enum):
     KEY_NORMALIZATION = 'key-normalization'
     CLI_INVOCATIONS = 'cli-invocations'
+    ADJUST_RULINGS = 'adjust-rulings'
 
 
 DEFAULT_TOPICS: Set[Topic] = set()