Merge branch 'tristan/deprecation-warnings-refactor' into 'master'

Refactor deprecation warning suppression

Closes #1291

See merge request BuildStream/buildstream!1892

30 files changed, 376 insertions, 193 deletions

diff --git a/NEWS b/NEWS
index ec6f5f352..0b6882dc8 100644
--- a/NEWS
+++ b/NEWS
@@ -8,6 +8,14 @@ CLI
   o `bst shell --build` will now automatically fetch missing sources.
 
 
+Format
+------
+
+  o BREAKING CHANGE: Now deprecation warnings are suppressed using the `allow-deprecated`
+    configuration with the plugin origins in project.conf, instead of on the
+    source/element overrides section (See issue #1291)
+
+
 ==================
 buildstream 1.93.3
 ==================
diff --git a/doc/source/format_project.rst b/doc/source/format_project.rst
index 65ca6c14d..211fc4dd0 100644
--- a/doc/source/format_project.rst
+++ b/doc/source/format_project.rst
@@ -404,7 +404,7 @@ plugin.
      # We want to use the `mysource` source plugin located in our
      # project's `plugins/sources` subdirectory.
      sources:
-       mysource: 0
+     - mysource
 
 
 Pip plugins
@@ -425,11 +425,60 @@ system.
      #
      package-name: potato
 
-     # We again must specify a minimal format version for the
-     # external plugin, it is allowed to be `0`.
+     # We again must specify specifically which plugins we
+     # want loaded from this origin.
      #
      elements:
-       starch: 0
+     - starch
+
+
+.. _project_plugins_deprecation:
+
+Suppressing deprecation warnings
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Plugins can be deprecated over time, and using deprecated plugins will
+trigger a warning when loading elements and sources which use
+deprecated plugin kinds.
+
+These deprecation warnings can be suppressed for the entire plugin
+origin or on a per plugin kind basis.
+
+To suppress all deprecation warnings from the origin, set the
+``allow-deprecated`` flag for the origin as follows:
+
+.. code:: yaml
+
+   plugins:
+
+   - origin: local
+     path: plugins/sources
+
+     # Suppress deprecation warnings for any plugins loaded here
+     allow-deprecated: True
+
+     sources:
+     - mysource
+
+
+In order to suppress deprecation warnings for a single element or
+source kind within an origin, you will have to use a dictionary
+to declare the specific plugin kind and set the ``allow-deprecated`` flag
+on that dictionary as follows:
+
+.. code:: yaml
+
+   plugins:
+
+   - origin: pip
+     package-name: potato
+
+     # Here we use a dictionary to declare the "starch"
+     # element kind, and specify that it is allowed to
+     # be deprecated.
+     #
+     elements:
+     - kind: starch
+       allow-deprecated: True
 
 
 .. _project_options:
diff --git a/src/buildstream/_loader/metasource.py b/src/buildstream/_loader/metasource.py
index 5466d3aa5..ddaa538f5 100644
--- a/src/buildstream/_loader/metasource.py
+++ b/src/buildstream/_loader/metasource.py
@@ -40,3 +40,4 @@ class MetaSource:
         self.config = config
         self.directory = directory
         self.first_pass = False
+        self.provenance = config.get_provenance()
diff --git a/src/buildstream/_pluginfactory/elementfactory.py b/src/buildstream/_pluginfactory/elementfactory.py
index 8879a4173..da6e8ac56 100644
--- a/src/buildstream/_pluginfactory/elementfactory.py
+++ b/src/buildstream/_pluginfactory/elementfactory.py
@@ -53,6 +53,6 @@ class ElementFactory(PluginFactory):
     #    LoadError (if the element itself took issue with the config)
     #
     def create(self, context, project, meta):
-        element_type, default_config = self.lookup(meta.kind)
+        element_type, default_config = self.lookup(context.messenger, meta.kind, meta.provenance)
         element = element_type(context, project, meta, default_config)
         return element
diff --git a/src/buildstream/_pluginfactory/pluginfactory.py b/src/buildstream/_pluginfactory/pluginfactory.py
index 27321c62f..2de110ed4 100644
--- a/src/buildstream/_pluginfactory/pluginfactory.py
+++ b/src/buildstream/_pluginfactory/pluginfactory.py
@@ -19,10 +19,15 @@
 
 import os
 import inspect
+from typing import Tuple, Type
 
 from .. import utils
+from ..plugin import Plugin
+from ..node import ProvenanceInformation
 from ..utils import UtilError
 from .._exceptions import PluginError
+from .._messenger import Messenger
+from .._message import Message, MessageType
 
 from .pluginorigin import PluginOrigin, PluginOriginType
 
@@ -61,6 +66,7 @@ class PluginFactory:
         self._base_type = base_type  # The base class plugins derive from
         self._types = {}  # Plugin type lookup table by kind
         self._origins = {}  # PluginOrigin lookup table by kind
+        self._allow_deprecated = {}  # Lookup table to check if a plugin is allowed to be deprecated
 
         # The PluginSource object
         self._plugin_base = plugin_base
@@ -115,14 +121,42 @@ class PluginFactory:
     # Fetches a type loaded from a plugin in this plugin context
     #
     # Args:
+    #     messenger (Messenger): The messenger
     #     kind (str): The kind of Plugin to create
+    #     provenance (ProvenanceInformation): The provenance from where
+    #                                         the plugin was referenced
     #
-    # Returns: the type associated with the given kind
+    # Returns:
+    #     (type): The type associated with the given kind
+    #     (str): A path to the YAML file holding the plugin's defaults, or None
     #
     # Raises: PluginError
     #
-    def lookup(self, kind):
-        return self._ensure_plugin(kind)
+    def lookup(self, messenger: Messenger, kind: str, provenance: ProvenanceInformation) -> Tuple[Type[Plugin], str]:
+        plugin_type, defaults = self._ensure_plugin(kind, provenance)
+
+        # We can be called with None for the messenger here in the
+        # case that we've been pickled through the scheduler (see jobpickler.py),
+        #
+        # In this case we know that we've already initialized and do not need
+        # to warn about deprecated plugins a second time.
+        if messenger is None:
+            return plugin_type, defaults
+
+        # After looking up the type, issue a warning if it's deprecated
+        #
+        # We do this here because we want to issue one warning for each time the
+        # plugin is used.
+        #
+        if plugin_type.BST_PLUGIN_DEPRECATED and not self._allow_deprecated[kind]:
+            message = Message(
+                MessageType.WARN,
+                "{}: Using deprecated plugin '{}'".format(provenance, kind),
+                detail=plugin_type.BST_PLUGIN_DEPRECATION_MESSAGE,
+            )
+            messenger.message(message)
+
+        return plugin_type, defaults
 
     # register_plugin_origin():
     #
@@ -131,8 +165,9 @@ class PluginFactory:
     # Args:
     #    kind (str): The kind identifier of the Plugin
     #    origin (PluginOrigin): The PluginOrigin providing the plugin
+    #    allow_deprecated (bool): Whether this plugin kind is allowed to be used in a deprecated state
     #
-    def register_plugin_origin(self, kind: str, origin: PluginOrigin):
+    def register_plugin_origin(self, kind: str, origin: PluginOrigin, allow_deprecated: bool):
         if kind in self._origins:
             raise PluginError(
                 "More than one {} plugin registered as kind '{}'".format(self._base_type.__name__, kind),
@@ -140,6 +175,7 @@ class PluginFactory:
             )
 
         self._origins[kind] = origin
+        self._allow_deprecated[kind] = allow_deprecated
 
     # all_loaded_plugins():
     #
@@ -197,7 +233,7 @@ class PluginFactory:
 
         return source, defaults
 
-    def _ensure_plugin(self, kind):
+    def _ensure_plugin(self, kind: str, provenance: ProvenanceInformation) -> Tuple[Type[Plugin], str]:
 
         if kind not in self._types:
             source = None
@@ -215,7 +251,10 @@ class PluginFactory:
             else:
                 # Try getting it from the core plugins
                 if kind not in self._site_source.list_plugins():
-                    raise PluginError("No {} type registered for kind '{}'".format(self._base_type.__name__, kind))
+                    raise PluginError(
+                        "{}: No {} type registered for kind '{}'".format(provenance, self._base_type.__name__, kind),
+                        reason="plugin-not-found",
+                    )
 
                 source = self._site_source
 
diff --git a/src/buildstream/_pluginfactory/pluginorigin.py b/src/buildstream/_pluginfactory/pluginorigin.py
index 50852711b..14d7a76bf 100644
--- a/src/buildstream/_pluginfactory/pluginorigin.py
+++ b/src/buildstream/_pluginfactory/pluginorigin.py
@@ -18,6 +18,9 @@
 import os
 
 from ..types import FastEnum
+from ..node import ScalarNode, MappingNode
+from .._exceptions import LoadError
+from ..exceptions import LoadErrorReason
 
 
 # PluginOriginType:
@@ -29,6 +32,17 @@ class PluginOriginType(FastEnum):
     PIP = "pip"
 
 
+# PluginConfiguration:
+#
+# An object representing the configuration of a single
+# plugin in the origin.
+#
+class PluginConfiguration:
+    def __init__(self, kind, allow_deprecated):
+        self.kind = kind
+        self.allow_deprecated = allow_deprecated
+
+
 # PluginOrigin
 #
 # Base class holding common properties of all origins.
@@ -36,18 +50,19 @@ class PluginOriginType(FastEnum):
 class PluginOrigin:
 
     # Common fields valid for all plugin origins
-    _COMMON_CONFIG_KEYS = ["origin", "sources", "elements"]
+    _COMMON_CONFIG_KEYS = ["origin", "sources", "elements", "allow-deprecated"]
 
     def __init__(self, origin_type):
 
         # Public
-        self.origin_type = origin_type
-        self.elements = []
-        self.sources = []
+        self.origin_type = origin_type  # The PluginOriginType
+        self.elements = {}  # A dictionary of PluginConfiguration
+        self.sources = {}  # A dictionary of PluginConfiguration objects
 
         # Private
         self._project = None
         self._kinds = {}
+        self._allow_deprecated = False
 
     # new_from_node()
     #
@@ -73,8 +88,14 @@ class PluginOrigin:
         origin._project = project
         origin._load(origin_node)
 
-        origin.elements = origin_node.get_str_list("elements", [])
-        origin.sources = origin_node.get_str_list("sources", [])
+        # Parse commonly defined aspects of PluginOrigins
+        origin._allow_deprecated = origin_node.get_bool("allow-deprecated", False)
+
+        element_sequence = origin_node.get_sequence("elements", [])
+        origin._load_plugin_configurations(element_sequence, origin.elements)
+
+        source_sequence = origin_node.get_sequence("sources", [])
+        origin._load_plugin_configurations(source_sequence, origin.sources)
 
         return origin
 
@@ -89,6 +110,38 @@ class PluginOrigin:
     def _load(self, origin_node):
         pass
 
+    # _load_plugin_configurations()
+    #
+    # Helper function to load the list of source or element
+    # PluginConfigurations
+    #
+    # Args:
+    #    sequence_node (SequenceNode): The list of configurations
+    #    dictionary (dict): The location to store the results
+    #
+    def _load_plugin_configurations(self, sequence_node, dictionary):
+
+        for node in sequence_node:
+
+            # Parse as a simple string
+            if type(node) is ScalarNode:  # pylint: disable=unidiomatic-typecheck
+                kind = node.as_str()
+                conf = PluginConfiguration(kind, self._allow_deprecated)
+
+            # Parse as a dictionary
+            elif type(node) is MappingNode:  # pylint: disable=unidiomatic-typecheck
+                node.validate_keys(["kind", "allow-deprecated"])
+                kind = node.get_str("kind")
+                allow_deprecated = node.get_bool("allow-deprecated", self._allow_deprecated)
+                conf = PluginConfiguration(kind, allow_deprecated)
+            else:
+                p = node.get_provenance()
+                raise LoadError(
+                    "{}: Plugin is not specified as a string or a dictionary".format(p), LoadErrorReason.INVALID_DATA
+                )
+
+            dictionary[kind] = conf
+
 
 # PluginOriginLocal
 #
diff --git a/src/buildstream/_pluginfactory/sourcefactory.py b/src/buildstream/_pluginfactory/sourcefactory.py
index 9f6a09784..5277577d4 100644
--- a/src/buildstream/_pluginfactory/sourcefactory.py
+++ b/src/buildstream/_pluginfactory/sourcefactory.py
@@ -54,6 +54,6 @@ class SourceFactory(PluginFactory):
     #    LoadError (if the source itself took issue with the config)
     #
     def create(self, context, project, meta):
-        source_type, _ = self.lookup(meta.kind)
+        source_type, _ = self.lookup(context.messenger, meta.kind, meta.provenance)
         source = source_type(context, project, meta)
         return source
diff --git a/src/buildstream/_project.py b/src/buildstream/_project.py
index 40524d7ad..45f3b4d34 100644
--- a/src/buildstream/_project.py
+++ b/src/buildstream/_project.py
@@ -951,10 +951,10 @@ class Project:
         origins = config.get_sequence("plugins", default=[])
         for origin_node in origins:
             origin = PluginOrigin.new_from_node(self, origin_node)
-            for kind in origin.elements:
-                output.element_factory.register_plugin_origin(kind, origin)
-            for kind in origin.sources:
-                output.source_factory.register_plugin_origin(kind, origin)
+            for kind, conf in origin.elements.items():
+                output.element_factory.register_plugin_origin(kind, origin, conf.allow_deprecated)
+            for kind, conf in origin.sources.items():
+                output.source_factory.register_plugin_origin(kind, origin, conf.allow_deprecated)
 
     # _warning_is_fatal():
     #
diff --git a/src/buildstream/_scheduler/jobs/jobpickler.py b/src/buildstream/_scheduler/jobs/jobpickler.py
index 1d47f67db..066e518c8 100644
--- a/src/buildstream/_scheduler/jobs/jobpickler.py
+++ b/src/buildstream/_scheduler/jobs/jobpickler.py
@@ -192,7 +192,7 @@ def _reduce_plugin_with_factory_dict(plugin, plugin_class_to_factory):
 
 
 def _new_plugin_from_reduction_args(factory, meta_kind):
-    cls, _ = factory.lookup(meta_kind)
+    cls, _ = factory.lookup(None, meta_kind, None)
     plugin = cls.__new__(cls)
 
     # Note that we rely on the `__project` member of the Plugin to keep
diff --git a/src/buildstream/plugin.py b/src/buildstream/plugin.py
index 935db6523..ff0604811 100644
--- a/src/buildstream/plugin.py
+++ b/src/buildstream/plugin.py
@@ -177,20 +177,18 @@ class Plugin:
     BST_PLUGIN_DEPRECATED = False
     """True if this element plugin has been deprecated.
 
-    If this is set to true, BuildStream will emmit a deprecation
-    warning when this plugin is loaded. This deprecation warning may
-    be suppressed on a plugin by plugin basis by setting
-    ``suppress-deprecation-warnings: true`` in the relevent section of
-    the project's :ref:`plugin configuration overrides <project_overrides>`.
+    If this is set to true, BuildStream will emit a deprecation warning
+    in any place where this plugin is used.
 
+    The deprecation warnings can be suppressed when defining the
+    :ref:`plugin origins in your project configuration <project_plugins_deprecation>`
     """
 
-    BST_PLUGIN_DEPRECATION_MESSAGE = ""
-    """ The message printed when this element shows a deprecation warning.
-
-    This should be set if BST_PLUGIN_DEPRECATED is True and should direct the user
-    to the deprecated plug-in's replacement.
+    BST_PLUGIN_DEPRECATION_MESSAGE = None
+    """An additional message to report when a plugin is deprecated
 
+    This can be used to refer the user to a suitable replacement or
+    alternative approach when the plugin is deprecated.
     """
 
     # Unique id generator for Plugins
@@ -272,11 +270,6 @@ class Plugin:
         self.__kind = modulename.split(".")[-1]
         self.debug("Created: {}".format(self))
 
-        # If this plugin has been deprecated, emit a warning.
-        if self.BST_PLUGIN_DEPRECATED and not self.__deprecation_warning_silenced():
-            detail = "Using deprecated plugin {}: {}".format(self.__kind, self.BST_PLUGIN_DEPRECATION_MESSAGE)
-            self.__message(MessageType.WARN, detail)
-
     def __del__(self):
         # Dont send anything through the Message() pipeline at destruction time,
         # any subsequent lookup of plugin by unique id would raise KeyError.
@@ -762,22 +755,6 @@ class Plugin:
         output.flush()
         self.status("Running host command", detail=command)
 
-    def __deprecation_warning_silenced(self):
-        if not self.BST_PLUGIN_DEPRECATED:
-            return False
-        else:
-            silenced_warnings = set()
-            project = self.__project
-
-            for key, value in project.element_overrides.items():
-                if value.get_bool("suppress-deprecation-warnings", default=False):
-                    silenced_warnings.add(key)
-            for key, value in project.source_overrides.items():
-                if value.get_bool("suppress-deprecation-warnings", default=False):
-                    silenced_warnings.add(key)
-
-            return self.get_kind() in silenced_warnings
-
     def __get_full_name(self):
         project = self.__project
         # Set the name, depending on element or source plugin type
diff --git a/tests/format/project.py b/tests/format/project.py
index c4b2a480a..d3de67222 100644
--- a/tests/format/project.py
+++ b/tests/format/project.py
@@ -153,20 +153,6 @@ def test_local_plugin_not_directory(cli, datafiles):
 
 
 @pytest.mark.datafiles(DATA_DIR)
-def test_plugin_load_allowed(cli, datafiles):
-    project = os.path.join(datafiles.dirname, datafiles.basename, "plugin-allowed")
-    result = cli.run(project=project, silent=True, args=["show", "element.bst"])
-    result.assert_success()
-
-
-@pytest.mark.datafiles(DATA_DIR)
-def test_plugin_load_forbidden(cli, datafiles):
-    project = os.path.join(datafiles.dirname, datafiles.basename, "plugin-forbidden")
-    result = cli.run(project=project, silent=True, args=["show", "element.bst"])
-    result.assert_main_error(ErrorDomain.PLUGIN, None)
-
-
-@pytest.mark.datafiles(DATA_DIR)
 @pytest.mark.parametrize("ref_storage", [("inline"), ("project.refs")])
 def test_plugin_no_load_ref(cli, datafiles, ref_storage):
     project = os.path.join(datafiles.dirname, datafiles.basename, "plugin-no-load-ref")
diff --git a/tests/format/project/plugin-allowed/__init__.py b/tests/format/project/plugin-allowed/__init__.py
deleted file mode 100644
index e69de29bb..000000000
--- a/tests/format/project/plugin-allowed/__init__.py
+++ /dev/null
diff --git a/tests/format/project/plugin-allowed/element.bst b/tests/format/project/plugin-allowed/element.bst
deleted file mode 100644
index 675938bec..000000000
--- a/tests/format/project/plugin-allowed/element.bst
+++ /dev/null
@@ -1 +0,0 @@
-kind: foo
diff --git a/tests/format/project/plugin-allowed/plugins/__init__.py b/tests/format/project/plugin-allowed/plugins/__init__.py
deleted file mode 100644
index e69de29bb..000000000
--- a/tests/format/project/plugin-allowed/plugins/__init__.py
+++ /dev/null
diff --git a/tests/format/project/plugin-allowed/plugins/foo.py b/tests/format/project/plugin-allowed/plugins/foo.py
deleted file mode 100644
index 76d9bfd3c..000000000
--- a/tests/format/project/plugin-allowed/plugins/foo.py
+++ /dev/null
@@ -1,19 +0,0 @@
-from buildstream import Element
-
-
-class FooElement(Element):
-
-    BST_MIN_VERSION = "2.0"
-
-    def configure(self, config):
-        pass
-
-    def preflight(self):
-        pass
-
-    def get_unique_key(self):
-        return "foo"
-
-
-def setup():
-    return FooElement
diff --git a/tests/format/project/plugin-allowed/project.conf b/tests/format/project/plugin-allowed/project.conf
deleted file mode 100644
index 97107edf6..000000000
--- a/tests/format/project/plugin-allowed/project.conf
+++ /dev/null
@@ -1,8 +0,0 @@
-name: test
-min-version: 2.0
-
-plugins:
-- origin: local
-  path: plugins
-  elements:
-  - foo
diff --git a/tests/format/project/plugin-forbidden/__init__.py b/tests/format/project/plugin-forbidden/__init__.py
deleted file mode 100644
index e69de29bb..000000000
--- a/tests/format/project/plugin-forbidden/__init__.py
+++ /dev/null
diff --git a/tests/format/project/plugin-forbidden/element.bst b/tests/format/project/plugin-forbidden/element.bst
deleted file mode 100644
index c8d51318c..000000000
--- a/tests/format/project/plugin-forbidden/element.bst
+++ /dev/null
@@ -1 +0,0 @@
-kind: bar
diff --git a/tests/format/project/plugin-forbidden/forbidden-plugins/__init__.py b/tests/format/project/plugin-forbidden/forbidden-plugins/__init__.py
deleted file mode 100644
index e69de29bb..000000000
--- a/tests/format/project/plugin-forbidden/forbidden-plugins/__init__.py
+++ /dev/null
diff --git a/tests/format/project/plugin-forbidden/project.conf b/tests/format/project/plugin-forbidden/project.conf
deleted file mode 100644
index 0211b2061..000000000
--- a/tests/format/project/plugin-forbidden/project.conf
+++ /dev/null
@@ -1,3 +0,0 @@
-name: test
-min-version: 2.0
-
diff --git a/tests/plugins/deprecationwarnings.py b/tests/plugins/deprecationwarnings.py
deleted file mode 100644
index a4da3ea72..000000000
--- a/tests/plugins/deprecationwarnings.py
+++ /dev/null
@@ -1,38 +0,0 @@
-# Pylint doesn't play well with fixtures and dependency injection from pytest
-# pylint: disable=redefined-outer-name
-
-import os
-
-import pytest
-
-from buildstream.testing import cli  # pylint: disable=unused-import
-
-
-DATA_DIR = os.path.join(os.path.dirname(os.path.realpath(__file__)), "deprecationwarnings")
-
-_DEPRECATION_MESSAGE = "Here is some detail."
-_DEPRECATION_WARNING = "Using deprecated plugin deprecated_plugin: {}".format(_DEPRECATION_MESSAGE)
-
-
-@pytest.mark.datafiles(DATA_DIR)
-def test_deprecation_warning_present(cli, datafiles):
-    project = str(datafiles)
-    result = cli.run(project=project, args=["show", "deprecated.bst"])
-    result.assert_success()
-    assert _DEPRECATION_WARNING in result.stderr
-
-
-@pytest.mark.datafiles(DATA_DIR)
-def test_suppress_deprecation_warning(cli, datafiles):
-    project = str(datafiles)
-    cli.run(project=project, args=["show", "manual.bst"])
-
-    element_overrides = "elements:\n" "  deprecated_plugin:\n" "    suppress-deprecation-warnings : True\n"
-
-    project_conf = os.path.join(project, "project.conf")
-    with open(project_conf, "a") as f:
-        f.write(element_overrides)
-
-    result = cli.run(project=project, args=["show", "deprecated.bst"])
-    result.assert_success()
-    assert _DEPRECATION_WARNING not in result.stderr
diff --git a/tests/plugins/deprecationwarnings/elements/deprecated.bst b/tests/plugins/deprecationwarnings/elements/deprecated.bst
deleted file mode 100644
index e80bd91cd..000000000
--- a/tests/plugins/deprecationwarnings/elements/deprecated.bst
+++ /dev/null
@@ -1 +0,0 @@
-kind: deprecated_plugin
\ No newline at end of file
diff --git a/tests/plugins/deprecationwarnings/plugins/elements/deprecated_plugin.py b/tests/plugins/deprecationwarnings/plugins/elements/deprecated_plugin.py
deleted file mode 100644
index 244009764..000000000
--- a/tests/plugins/deprecationwarnings/plugins/elements/deprecated_plugin.py
+++ /dev/null
@@ -1,12 +0,0 @@
-from buildstream import BuildElement
-
-
-class DeprecatedPlugin(BuildElement):
-    BST_MIN_VERSION = "2.0"
-    BST_PLUGIN_DEPRECATED = True
-    BST_PLUGIN_DEPRECATION_MESSAGE = "Here is some detail."
-
-
-# Plugin entry point
-def setup():
-    return DeprecatedPlugin
diff --git a/tests/plugins/deprecationwarnings/plugins/elements/deprecated_plugin.yaml b/tests/plugins/deprecationwarnings/plugins/elements/deprecated_plugin.yaml
deleted file mode 100644
index 1c07cd8b2..000000000
--- a/tests/plugins/deprecationwarnings/plugins/elements/deprecated_plugin.yaml
+++ /dev/null
@@ -1,22 +0,0 @@
-# Deprecated-plugin build element does not provide any default
-# build commands
-config:
-
-  # Commands for configuring the software
-  #
-  configure-commands: []
-
-  # Commands for building the software
-  #
-  build-commands: []
-
-  # Commands for installing the software into a
-  # destination folder
-  #
-  install-commands: []
-
-  # Commands for stripping installed binaries
-  #
-  strip-commands:
-  - |
-    %{strip-binaries}
\ No newline at end of file
diff --git a/tests/plugins/deprecationwarnings/project.conf b/tests/plugins/deprecationwarnings/project.conf
deleted file mode 100644
index 9e03afe0a..000000000
--- a/tests/plugins/deprecationwarnings/project.conf
+++ /dev/null
@@ -1,15 +0,0 @@
-# Unique project name
-name: deprecation-warnings
-
-# Required BuildStream version
-min-version: 2.0
-
-# Subdirectory where elements are stored
-element-path: elements
-
-plugins:
-
-- origin: local
-  path: plugins/elements
-  elements:
-  - deprecated_plugin
diff --git a/tests/plugins/loading.py b/tests/plugins/loading.py
index a368e9952..152f4080b 100644
--- a/tests/plugins/loading.py
+++ b/tests/plugins/loading.py
@@ -200,3 +200,106 @@ def test_incompatible_minor_version(cli, datafiles, plugin_type):
 
     result = cli.run(project=project, args=["show", "element.bst"])
     result.assert_main_error(ErrorDomain.PLUGIN, "incompatible-minor-version")
+
+
+@pytest.mark.datafiles(DATA_DIR)
+@pytest.mark.parametrize("plugin_type", [("elements"), ("sources")])
+def test_plugin_not_found(cli, datafiles, plugin_type):
+    project = str(datafiles)
+
+    setup_element(project, plugin_type, "notfound")
+
+    result = cli.run(project=project, args=["show", "element.bst"])
+    result.assert_main_error(ErrorDomain.PLUGIN, "plugin-not-found")
+
+
+@pytest.mark.datafiles(DATA_DIR)
+@pytest.mark.parametrize("plugin_type", [("elements"), ("sources")])
+def test_plugin_found(cli, datafiles, plugin_type):
+    project = str(datafiles)
+
+    update_project(
+        project,
+        {
+            "plugins": [
+                {"origin": "local", "path": os.path.join("plugins", plugin_type, "found"), plugin_type: ["found"],}
+            ]
+        },
+    )
+    setup_element(project, plugin_type, "found")
+
+    result = cli.run(project=project, args=["show", "element.bst"])
+    result.assert_success()
+
+
+@pytest.mark.datafiles(DATA_DIR)
+@pytest.mark.parametrize("plugin_type", [("elements"), ("sources")])
+def test_deprecation_warnings(cli, datafiles, plugin_type):
+    project = str(datafiles)
+
+    update_project(
+        project,
+        {
+            "plugins": [
+                {
+                    "origin": "local",
+                    "path": os.path.join("plugins", plugin_type, "deprecated"),
+                    plugin_type: ["deprecated"],
+                }
+            ]
+        },
+    )
+    setup_element(project, plugin_type, "deprecated")
+
+    result = cli.run(project=project, args=["show", "element.bst"])
+    result.assert_success()
+    assert "Here is some detail." in result.stderr
+
+
+@pytest.mark.datafiles(DATA_DIR)
+@pytest.mark.parametrize("plugin_type", [("elements"), ("sources")])
+def test_deprecation_warning_suppressed_by_origin(cli, datafiles, plugin_type):
+    project = str(datafiles)
+
+    update_project(
+        project,
+        {
+            "plugins": [
+                {
+                    "origin": "local",
+                    "path": os.path.join("plugins", plugin_type, "deprecated"),
+                    "allow-deprecated": True,
+                    plugin_type: ["deprecated"],
+                }
+            ]
+        },
+    )
+    setup_element(project, plugin_type, "deprecated")
+
+    result = cli.run(project=project, args=["show", "element.bst"])
+    result.assert_success()
+    assert "Here is some detail." not in result.stderr
+
+
+@pytest.mark.datafiles(DATA_DIR)
+@pytest.mark.parametrize("plugin_type", [("elements"), ("sources")])
+def test_deprecation_warning_suppressed_specifically(cli, datafiles, plugin_type):
+    project = str(datafiles)
+
+    update_project(
+        project,
+        {
+            "plugins": [
+                {
+                    "origin": "local",
+                    "path": os.path.join("plugins", plugin_type, "deprecated"),
+                    plugin_type: [{"kind": "deprecated", "allow-deprecated": True}],
+                }
+            ]
+        },
+    )
+    setup_element(project, plugin_type, "deprecated")
+
+    result = cli.run(project=project, args=["show", "element.bst"])
+    result.assert_success()
+    assert "Here is some detail." not in result.stderr
diff --git a/tests/plugins/loading/plugins/elements/deprecated/deprecated.py b/tests/plugins/loading/plugins/elements/deprecated/deprecated.py
new file mode 100644
index 000000000..7184710bc
--- /dev/null
+++ b/tests/plugins/loading/plugins/elements/deprecated/deprecated.py
@@ -0,0 +1,21 @@
+from buildstream import Element
+
+
+class Deprecated(Element):
+    BST_MIN_VERSION = "2.0"
+    BST_PLUGIN_DEPRECATED = True
+    BST_PLUGIN_DEPRECATION_MESSAGE = "Here is some detail."
+
+    def configure(self, node):
+        pass
+
+    def preflight(self):
+        pass
+
+    def get_unique_key(self):
+        return {}
+
+
+# Plugin entry point
+def setup():
+    return Deprecated
diff --git a/tests/format/project/plugin-forbidden/forbidden-plugins/forbidden-plugin.py b/tests/plugins/loading/plugins/elements/found/found.py
index 76d9bfd3c..34a7e4398 100644
--- a/tests/format/project/plugin-forbidden/forbidden-plugins/forbidden-plugin.py
+++ b/tests/plugins/loading/plugins/elements/found/found.py
@@ -1,19 +1,19 @@
 from buildstream import Element
 
 
-class FooElement(Element):
-
+class Found(Element):
     BST_MIN_VERSION = "2.0"
 
-    def configure(self, config):
+    def configure(self, node):
         pass
 
     def preflight(self):
         pass
 
     def get_unique_key(self):
-        return "foo"
+        return {}
 
 
+# Plugin entry point
 def setup():
-    return FooElement
+    return Found
diff --git a/tests/plugins/loading/plugins/sources/deprecated/deprecated.py b/tests/plugins/loading/plugins/sources/deprecated/deprecated.py
new file mode 100644
index 000000000..6203eb2fa
--- /dev/null
+++ b/tests/plugins/loading/plugins/sources/deprecated/deprecated.py
@@ -0,0 +1,34 @@
+from buildstream import Source
+
+
+class Deprecated(Source):
+    BST_MIN_VERSION = "2.0"
+    BST_PLUGIN_DEPRECATED = True
+    BST_PLUGIN_DEPRECATION_MESSAGE = "Here is some detail."
+
+    def configure(self, node):
+        pass
+
+    def preflight(self):
+        pass
+
+    def get_unique_key(self):
+        return {}
+
+    def load_ref(self, node):
+        pass
+
+    def get_ref(self):
+        return {}
+
+    def set_ref(self, ref, node):
+        pass
+
+    def is_cached(self):
+        return False
+
+
+# Plugin entry point
+def setup():
+
+    return Deprecated
diff --git a/tests/plugins/loading/plugins/sources/found/found.py b/tests/plugins/loading/plugins/sources/found/found.py
new file mode 100644
index 000000000..4ab40f005
--- /dev/null
+++ b/tests/plugins/loading/plugins/sources/found/found.py
@@ -0,0 +1,32 @@
+from buildstream import Source
+
+
+class Found(Source):
+    BST_MIN_VERSION = "2.0"
+
+    def configure(self, node):
+        pass
+
+    def preflight(self):
+        pass
+
+    def get_unique_key(self):
+        return {}
+
+    def load_ref(self, node):
+        pass
+
+    def get_ref(self):
+        return {}
+
+    def set_ref(self, ref, node):
+        pass
+
+    def is_cached(self):
+        return False
+
+
+# Plugin entry point
+def setup():
+
+    return Found