Re-type config paths in ConfigErrors to be StrSequences (#15615)

Part of #14809.

Signed-off-by: Sean Quah <seanq@matrix.org>

changelog.d/15615.misc

@@ -0,0 +1 @@
+Re-type config paths in `ConfigError`s to be `StrSequence`s instead of `Iterable[str]`s.

synapse/config/_base.py

@@ -44,6 +44,7 @@
 import pkg_resources
 import yaml
 
+from synapse.types import StrSequence
 from synapse.util.templates import _create_mxc_to_http_filter, _format_ts_filter
 
 logger = logging.getLogger(__name__)
@@ -58,7 +59,7 @@ class ConfigError(Exception):
  the problem lies.
  """
 
- def __init__(self, msg: str, path: Optional[Iterable[str]] = None):
+ def __init__(self, msg: str, path: Optional[StrSequence] = None):
  self.msg = msg
  self.path = path
 

synapse/config/_base.pyi

@@ -61,9 +61,10 @@ from synapse.config import ( # noqa: F401
  voip,
  workers,
 )
+from synapse.types import StrSequence
 
 class ConfigError(Exception):
- def __init__(self, msg: str, path: Optional[Iterable[str]] = None):
+ def __init__(self, msg: str, path: Optional[StrSequence] = None):
  self.msg = msg
  self.path = path
 

synapse/config/_util.py

@@ -11,17 +11,17 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-from typing import Any, Dict, Iterable, Type, TypeVar
+from typing import Any, Dict, Type, TypeVar
 
 import jsonschema
 from pydantic import BaseModel, ValidationError, parse_obj_as
 
 from synapse.config._base import ConfigError
-from synapse.types import JsonDict
+from synapse.types import JsonDict, StrSequence
 
 
 def validate_config(
- json_schema: JsonDict, config: Any, config_path: Iterable[str]
+ json_schema: JsonDict, config: Any, config_path: StrSequence
 ) -> None:
  """Validates a config setting against a JsonSchema definition
 
@@ -45,7 +45,7 @@ def validate_config(
 
 
 def json_error_to_config_error(
- e: jsonschema.ValidationError, config_path: Iterable[str]
+ e: jsonschema.ValidationError, config_path: StrSequence
 ) -> ConfigError:
  """Converts a json validation error to a user-readable ConfigError
 

synapse/config/oembed.py

@@ -19,7 +19,7 @@
 import attr
 import pkg_resources
 
-from synapse.types import JsonDict
+from synapse.types import JsonDict, StrSequence
 
 from ._base import Config, ConfigError
 from ._util import validate_config
@@ -80,7 +80,7 @@ def _parse_and_validate_providers(
  )
 
  def _parse_and_validate_provider(
- self, providers: List[JsonDict], config_path: Iterable[str]
+ self, providers: List[JsonDict], config_path: StrSequence
  ) -> Iterable[OEmbedEndpointConfig]:
  # Ensure it is the proper form.
  validate_config(
@@ -112,7 +112,7 @@ def _parse_and_validate_provider(
  api_endpoint, patterns, endpoint.get("formats")
  )
 
- def _glob_to_pattern(self, glob: str, config_path: Iterable[str]) -> Pattern:
+ def _glob_to_pattern(self, glob: str, config_path: StrSequence) -> Pattern:
  """
  Convert the glob into a sane regular expression to match against. The
  rules followed will be slightly different for the domain portion vs.

synapse/config/server.py

@@ -27,7 +27,7 @@
 from twisted.conch.ssh.keys import Key
 
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
-from synapse.types import JsonDict
+from synapse.types import JsonDict, StrSequence
 from synapse.util.module_loader import load_module
 from synapse.util.stringutils import parse_and_validate_server_name
 
@@ -73,7 +73,7 @@ def _6to4(network: IPNetwork) -> IPNetwork:
 def generate_ip_set(
  ip_addresses: Optional[Iterable[str]],
  extra_addresses: Optional[Iterable[str]] = None,
- config_path: Optional[Iterable[str]] = None,
+ config_path: Optional[StrSequence] = None,
 ) -> IPSet:
  """
  Generate an IPSet from a list of IP addresses or CIDRs.

synapse/types/__init__.py

@@ -84,7 +84,15 @@
 
 # Collection[str] that does not include str itself; str being a Sequence[str]
 # is very misleading and results in bugs.
+#
+# StrCollection is an unordered collection of strings. If ordering is important,
+# StrSequence can be used instead.
 StrCollection = Union[Tuple[str, ...], List[str], AbstractSet[str]]
+# Sequence[str] that does not include str itself; str being a Sequence[str]
+# is very misleading and results in bugs.
+#
+# Unlike StrCollection, StrSequence is an ordered collection of strings.
+StrSequence = Union[Tuple[str, ...], List[str]]
 
 
 # Note that this seems to require inheriting *directly* from Interface in order

synapse/util/module_loader.py

@@ -14,17 +14,17 @@
 
 import importlib
 import importlib.util
-import itertools
 from types import ModuleType
-from typing import Any, Iterable, Tuple, Type
+from typing import Any, Tuple, Type
 
 import jsonschema
 
 from synapse.config._base import ConfigError
 from synapse.config._util import json_error_to_config_error
+from synapse.types import StrSequence
 
 
-def load_module(provider: dict, config_path: Iterable[str]) -> Tuple[Type, Any]:
+def load_module(provider: dict, config_path: StrSequence) -> Tuple[Type, Any]:
  """Loads a synapse module with its config
 
  Args:
@@ -39,9 +39,7 @@ def load_module(provider: dict, config_path: Iterable[str]) -> Tuple[Type, Any]:
 
  modulename = provider.get("module")
  if not isinstance(modulename, str):
- raise ConfigError(
- "expected a string", path=itertools.chain(config_path, ("module",))
- )
+ raise ConfigError("expected a string", path=tuple(config_path) + ("module",))
 
  # We need to import the module, and then pick the class out of
  # that, so we split based on the last dot.
@@ -55,19 +53,17 @@ def load_module(provider: dict, config_path: Iterable[str]) -> Tuple[Type, Any]:
  try:
  provider_config = provider_class.parse_config(module_config)
  except jsonschema.ValidationError as e:
- raise json_error_to_config_error(
- e, itertools.chain(config_path, ("config",))
- )
+ raise json_error_to_config_error(e, tuple(config_path) + ("config",))
  except ConfigError as e:
  raise _wrap_config_error(
  "Failed to parse config for module %r" % (modulename,),
- prefix=itertools.chain(config_path, ("config",)),
+ prefix=tuple(config_path) + ("config",),
  e=e,
  )
  except Exception as e:
  raise ConfigError(
  "Failed to parse config for module %r" % (modulename,),
- path=itertools.chain(config_path, ("config",)),
+ path=tuple(config_path) + ("config",),
  ) from e
  else:
  provider_config = module_config
@@ -92,17 +88,15 @@ def load_python_module(location: str) -> ModuleType:
  return mod
 
 
-def _wrap_config_error(
- msg: str, prefix: Iterable[str], e: ConfigError
-) -> "ConfigError":
+def _wrap_config_error(msg: str, prefix: StrSequence, e: ConfigError) -> "ConfigError":
  """Wrap a relative ConfigError with a new path
 
  This is useful when we have a ConfigError with a relative path due to a problem
  parsing part of the config, and we now need to set it in context.
  """
  path = prefix
  if e.path:
- path = itertools.chain(prefix, e.path)
+ path = tuple(prefix) + tuple(e.path)
 
  e1 = ConfigError(msg, path)