replace logger.warning with warn_or_error

Uses `warn_or_error` to log _or_ raise errors depending on arguments
passed.

CHANGELOG.md

@@ -15,6 +15,7 @@
 - Add generic tests defined on sources to the manifest once, not twice ([#3347](https://github.com/dbt-labs/dbt/issues/3347), [#3880](https://github.com/dbt-labs/dbt/pull/3880))
 - Skip partial parsing if certain macros have changed ([#3810](https://github.com/dbt-labs/dbt/issues/3810), [#3982](https://github.com/dbt-labs/dbt/pull/3892))
 - Enable cataloging of unlogged Postgres tables ([3961](https://github.com/dbt-labs/dbt/issues/3961), [#3993](https://github.com/dbt-labs/dbt/pull/3993))
+- Return an error instead of a warning when runing with `--warn-error` and no models are selected ([#4006](https://github.com/dbt-labs/dbt/issues/4006), [#4019](https://github.com/dbt-labs/dbt/pull/4019))
 
 ### Under the hood
 
@@ -34,6 +35,7 @@ Contributors:
 - [@dave-connors-3](https://github.com/dave-connors-3) ([#3920](https://github.com/dbt-labs/dbt/issues/3920))
 - [@kadero](https://github.com/kadero) ([#3952](https://github.com/dbt-labs/dbt/issues/3952))
 - [@samlader](https://github.com/samlader) ([#3993](https://github.com/dbt-labs/dbt/pull/3993))
+- [@laxjesse](https://github.com/laxjesse) ([#4019](https://github.com/dbt-labs/dbt/pull/4019))
 
 ## dbt 0.21.0 (October 04, 2021)
 

core/dbt/task/list.py

@@ -8,8 +8,8 @@
 from dbt.task.runnable import GraphRunnableTask, ManifestTask
 from dbt.task.test import TestSelector
 from dbt.node_types import NodeType
-from dbt.exceptions import RuntimeException, InternalException
-from dbt.logger import log_manager, GLOBAL_LOGGER as logger
+from dbt.exceptions import RuntimeException, InternalException, warn_or_error
+from dbt.logger import log_manager
 
 
 class ListTask(GraphRunnableTask):
@@ -61,7 +61,7 @@ def _iterate_selected_nodes(self):
         spec = self.get_selection_spec()
         nodes = sorted(selector.get_selected(spec))
         if not nodes:
-            logger.warning('No nodes selected!')
+            warn_or_error('No nodes selected!')
             return
         if self.manifest is None:
             raise InternalException(

core/dbt/task/runnable.py

@@ -39,6 +39,7 @@
     NotImplementedException,
     RuntimeException,
     FailFastException,
+    warn_or_error,
 )
 
 from dbt.graph import (
@@ -438,8 +439,8 @@ def run(self):
             )
 
         if len(self._flattened_nodes) == 0:
-            logger.warning("\nWARNING: Nothing to do. Try checking your model "
-                           "configs and model specification args")
+            warn_or_error("\nWARNING: Nothing to do. Try checking your model "
+                          "configs and model specification args")
             result = self.get_result(
                 results=[],
                 generated_at=datetime.utcnow(),