flash: move metadata extension to where it is used

There is only one use case that uses the extended metadata.json, so we
can simplify things by extending it only where it is actually needed.

Author: dlech

pybricksdev/cli/flash.py

@@ -2,6 +2,7 @@
 # Copyright (c) 2019-2022 The Pybricks Authors
 
 import asyncio
+import hashlib
 import json
 import logging
 import sys
@@ -310,10 +311,15 @@ async def flash_firmware(firmware_zip: BinaryIO, new_name: Optional[str]) -> Non
                 bytearray(archive.open("install_pybricks.py").read()),
             )
 
+            extended_metadata = metadata.copy()
+
+            # Add extended metadata needed by install_pybricks.py
+            extended_metadata["firmware-sha256"] = hashlib.sha256(firmware).hexdigest()
+
             # Upload metadata.
             await hub.upload_file(
                 "_firmware/firmware.metadata.json",
-                json.dumps(metadata, indent=4).encode(),
+                json.dumps(extended_metadata, indent=4).encode(),
             )
 
             # Upload Pybricks firmware

pybricksdev/firmware.py

@@ -97,17 +97,3 @@ def firmware_metadata_is_v2(
     metadata: AnyFirmwareMetadata,
 ) -> TypeGuard[AnyFirmwareV2Metadata]:
     return metadata["metadata-version"].startswith("2.")
-
-
-class ExtendedFirmwareMetadata(
-    FirmwareMetadataV110, TypedDict("Extended", {"firmware-sha256": str})
-):
-    # NB: Ideally, this should inherit from AnyFirmwareMetadata instead of
-    # FirmwareMetadataV110 but that is not technically possible because being
-    # a Union it has a different meta class from TypedDict
-    """
-    Type for data contained in ``firmware.metadata.json`` files of any version
-    with extended data added.
-
-    The extended data is used by the ``install_pybricks.py`` script.
-    """

pybricksdev/flash.py

@@ -2,7 +2,6 @@
 # Copyright (c) 2019-2022 The Pybricks Authors
 
 import asyncio
-import hashlib
 import io
 import json
 import logging
@@ -24,7 +23,6 @@
 from .firmware import (
     AnyFirmwareV1Metadata,
     AnyFirmwareV2Metadata,
-    ExtendedFirmwareMetadata,
     AnyFirmwareMetadata,
     firmware_metadata_is_v1,
     firmware_metadata_is_v2,
@@ -132,7 +130,7 @@ async def _create_firmware_v2(
 
 async def create_firmware(
     firmware_zip: Union[str, os.PathLike, BinaryIO], name: Optional[str] = None
-) -> Tuple[bytes, ExtendedFirmwareMetadata]:
+) -> Tuple[bytes, AnyFirmwareMetadata]:
     """Creates a firmware blob from base firmware and an optional custom name.
 
     Arguments:
@@ -142,8 +140,7 @@ async def create_firmware(
             A custom name for the hub.
 
     Returns:
-        Composite binary blob with correct padding and checksum and
-        extended metadata for this firmware file.
+        Tuple of composite binary blob for flashing and the metadata.
 
     Raises:
         ValueError:
@@ -166,9 +163,6 @@ async def create_firmware(
                 f"unsupported metadata version: {metadata['metadata-version']}"
             )
 
-        # Add extended metadata needed by install_pybricks.py
-        metadata["firmware-sha256"] = hashlib.sha256(firmware).hexdigest()
-
         return firmware, metadata