Resolve circular dependency

Signed-off-by: Cristian Le <[email protected]>

docs/scripts/generate-plugins.py

@@ -6,6 +6,7 @@
 from typing import Any
 
 import tmt.checks
+import tmt.dataclasses
 import tmt.log
 import tmt.plugins
 import tmt.steps
@@ -36,7 +37,7 @@
 def _is_ignored(
         container: ContainerClass,
         field: dataclasses.Field[Any],
-        metadata: tmt.utils.FieldMetadata) -> bool:
+        metadata: tmt.dataclasses.FieldMetadata) -> bool:
     """ Check whether a given field is to be ignored in documentation """
 
     if field.name in ('how', '_OPTIONLESS_FIELDS'):
@@ -51,7 +52,7 @@ def _is_ignored(
 def _is_inherited(
         container: ContainerClass,
         field: dataclasses.Field[Any],
-        metadata: tmt.utils.FieldMetadata) -> bool:
+        metadata: tmt.dataclasses.FieldMetadata) -> bool:
     """ Check whether a given field is inherited from step data base class """
 
     # TODO: for now, it's a list, but inspecting the actual tree of classes

tmt/dataclasses.py

@@ -1,20 +1,22 @@
 """ Tmt dataclass wrappers """
 
+from __future__ import annotations
+
 import dataclasses
+import functools
 import textwrap
 from collections.abc import Sequence
 from dataclasses import _MISSING_TYPE, MISSING, asdict, dataclass, fields, is_dataclass, replace
-from typing import TYPE_CHECKING, Any, Callable, Optional, TypeVar, Union, overload
-
-import tmt.utils
+from typing import TYPE_CHECKING, Any, Callable, Generic, Optional, TypeVar, Union, overload
 
 if TYPE_CHECKING:
     import tmt.log
     import tmt.options
 
 __all__ = [
-    "_MISSING_TYPE",
+    "FieldMetadata",
     "MISSING",
+    "_MISSING_TYPE",
     "asdict",
     "dataclass",
     "field",
@@ -23,27 +25,26 @@
     "replace",
     ]
 
-if TYPE_CHECKING:
-    Field = dataclasses.Field
-
-
 # A stand-in variable for generic use.
 T = TypeVar('T')
 
-#: Type of field's normalization callback.
-NormalizeCallback = Callable[[str, Any, tmt.log.Logger], T]
+if TYPE_CHECKING:
+    Field = dataclasses.Field
 
-#: Type of field's exporter callback.
-FieldExporter = Callable[[T], Any]
+    #: Type of field's normalization callback.
+    NormalizeCallback = Callable[[str, Any, tmt.log.Logger], T]
 
-#: Type of field's CLI option specification.
-FieldCLIOption = Union[str, Sequence[str]]
+    #: Type of field's exporter callback.
+    FieldExporter = Callable[[T], Any]
 
-#: Type of field's serialization callback.
-SerializeCallback = Callable[[T], Any]
+    #: Type of field's CLI option specification.
+    FieldCLIOption = Union[str, Sequence[str]]
 
-#: Type of field's unserialization callback.
-UnserializeCallback = Callable[[Any], T]
+    #: Type of field's serialization callback.
+    SerializeCallback = Callable[[T], Any]
+
+    #: Type of field's unserialization callback.
+    UnserializeCallback = Callable[[Any], T]
 
 # Override field definition
 
@@ -86,7 +87,7 @@ def field(
         multiple: bool = False,
         metavar: Optional[str] = None,
         envvar: Optional[str] = None,
-        deprecated: Optional['tmt.options.Deprecated'] = None,
+        deprecated: Optional[tmt.options.Deprecated] = None,
         help: Optional[str] = None,
         show_default: bool = False,
         internal: bool = False,
@@ -112,7 +113,7 @@ def field(
         multiple: bool = False,
         metavar: Optional[str] = None,
         envvar: Optional[str] = None,
-        deprecated: Optional['tmt.options.Deprecated'] = None,
+        deprecated: Optional[tmt.options.Deprecated] = None,
         help: Optional[str] = None,
         show_default: bool = False,
         internal: bool = False,
@@ -137,7 +138,7 @@ def field(
         multiple: bool = False,
         metavar: Optional[str] = None,
         envvar: Optional[str] = None,
-        deprecated: Optional['tmt.options.Deprecated'] = None,
+        deprecated: Optional[tmt.options.Deprecated] = None,
         help: Optional[str] = None,
         show_default: bool = False,
         internal: bool = False,
@@ -163,7 +164,7 @@ def field(
         multiple: bool = False,
         metavar: Optional[str] = None,
         envvar: Optional[str] = None,
-        deprecated: Optional['tmt.options.Deprecated'] = None,
+        deprecated: Optional[tmt.options.Deprecated] = None,
         help: Optional[str] = None,
         show_default: bool = False,
         internal: bool = False,
@@ -232,7 +233,7 @@ def field(
             raise tmt.utils.GeneralError(
                 "Container field must have a boolean default value when it is a flag.")
 
-    metadata: tmt.utils.FieldMetadata[T] = tmt.utils.FieldMetadata(
+    metadata: FieldMetadata[T] = FieldMetadata(
         internal=internal,
         help=textwrap.dedent(help).strip() if help else None,
         _metavar=metavar,
@@ -259,3 +260,147 @@ def field(
         default_factory=default_factory or dataclasses.MISSING,
         metadata={'tmt': metadata}
         )
+
+
+@dataclasses.dataclass
+class FieldMetadata(Generic[T]):
+    """
+    A dataclass metadata container used by our custom dataclass field management.
+
+    Attached to fields defined with :py:func:`field`
+    """
+
+    internal: bool = False
+
+    #: Help text documenting the field.
+    help: Optional[str] = None
+
+    #: If field accepts a value, this string would represent it in documentation.
+    #: This stores the metavar provided when field was created - it may be unset.
+    #: py:attr:`metavar` provides the actual metavar to be used.
+    _metavar: Optional[str] = None
+
+    #: The default value for the field.
+    default: Optional[T] = None
+
+    #: A zero-argument callable that will be called when a default value is
+    #: needed for the field.
+    default_factory: Optional[Callable[[], T]] = None
+
+    #: Marks the fields as a flag.
+    is_flag: bool = False
+
+    #: Marks the field as accepting multiple values. When used on command line,
+    #: the option could be used multiple times, accumulating values.
+    multiple: bool = False
+
+    #: If set, show the default value in command line help.
+    show_default: bool = False
+
+    #: Either a list of allowed values the field can take, or a zero-argument
+    #: callable that would return such a list.
+    _choices: Union[None, Sequence[str], Callable[[], Sequence[str]]] = None
+
+    #: Environment variable providing value for the field.
+    envvar: Optional[str] = None
+
+    #: Mark the option as deprecated. Instance of :py:class:`Deprecated`
+    #: describes the version in which the field was deprecated plus an optional
+    #: hint with the recommended alternative. Documentation and help texts would
+    #: contain this info.
+    deprecated: Optional[tmt.options.Deprecated] = None
+
+    #: One or more command-line option names.
+    cli_option: Optional[FieldCLIOption] = None
+
+    #: A normalization callback to call when loading the value from key source
+    #: (performed by :py:class:`NormalizeKeysMixin`).
+    normalize_callback: Optional[NormalizeCallback[T]] = None
+
+    # Callbacks for custom serialize/unserialize operations (performed by
+    # :py:class:`SerializableContainer`).
+    serialize_callback: Optional[SerializeCallback[T]] = None
+    unserialize_callback: Optional[SerializeCallback[T]] = None
+
+    #: An export callback to call when exporting the field (performed by
+    #: :py:class:`tmt.export.Exportable`).
+    export_callback: Optional[FieldExporter[T]] = None
+
+    #: CLI option parameters, for lazy option creation.
+    _option_args: Optional[FieldCLIOption] = None
+    _option_kwargs: dict[str, Any] = dataclasses.field(default_factory=dict)
+
+    #: A :py:func:`click.option` decorator defining a corresponding CLI option.
+    _option: Optional[tmt.options.ClickOptionDecoratorType] = None
+
+    @functools.cached_property
+    def choices(self) -> Optional[Sequence[str]]:
+        """ A list of allowed values the field can take """
+
+        if isinstance(self._choices, (list, tuple)):
+            return list(self._choices)
+
+        if callable(self._choices):
+            return self._choices()
+
+        return None
+
+    @functools.cached_property
+    def metavar(self) -> Optional[str]:
+        """ Placeholder for field's value in documentation and help """
+
+        if self._metavar:
+            return self._metavar
+
+        if self.choices:
+            return '|'.join(self.choices)
+
+        return None
+
+    @property
+    def has_default(self) -> bool:
+        """ Whether the field has a default value """
+
+        return self.default_factory is not None \
+            or self.default is not dataclasses.MISSING
+
+    @property
+    def materialized_default(self) -> Optional[T]:
+        """ Returns the actual default value of the field """
+
+        if self.default_factory is not None:
+            return self.default_factory()
+
+        if self.default is not dataclasses.MISSING:
+            return self.default
+
+        return None
+
+    @property
+    def option(self) -> Optional[tmt.options.ClickOptionDecoratorType]:
+        if self._option is None and self.cli_option:
+            from tmt.options import option
+
+            self._option_args = (self.cli_option,) if isinstance(self.cli_option, str) \
+                else self.cli_option
+
+            self._option_kwargs.update({
+                'is_flag': self.is_flag,
+                'multiple': self.multiple,
+                'envvar': self.envvar,
+                'metavar': self.metavar,
+                'choices': self.choices,
+                'show_default': self.show_default,
+                'help': self.help,
+                'deprecated': self.deprecated
+                })
+
+            if self.default is not dataclasses.MISSING and not self.is_flag:
+                self._option_kwargs['default'] = self.default
+
+            self._option = option(
+                *self._option_args,
+                **self._option_kwargs
+                )
+
+        return self._option