get the automated generation of test cases working again (#1448)

# Description

@swift-nav/algint-team

This pr fixes the json2test script using UV, which installs dependencies
on the fly. I tried hard to make it so that it could easily be called
from any directory & link to the local version of SBP, but throwing in
the towel under the theory that working but less than ideal is better
than not working.

---------

Co-authored-by: Ivan Smolyakov <[email protected]>
Co-authored-by: Ivan Smolyakov <[email protected]>
Co-authored-by: Ivan Smolyakov <[email protected]>

HOWTO.md

@@ -87,7 +87,9 @@ python missing.py --host [HOST] --port [PORT]
 
 ### New Messages
 The `json2test` script can be used to automatically generate tests for newly
-defined messages.
+defined messages. The json2test script uses [uv](https://docs.astral.sh/uv/) to
+manage its dependencies, which can be installed following the instructions on that
+website
 
 To use `json2test` a JSON file should be hand written with example contents of a
 message. For example, to generate tests for the `MSG_HEARTBEAT` message (which
@@ -105,13 +107,19 @@ form:
 And then generate a test for using `json2test` with:
 
 ```shell
-PYTHONPATH="python/" python generator/json2test.py --input heartbeat.json --output spec/tests/yaml/swiftnav/sbp/system/test_MsgHeartbeat.yaml
+uv -n run json2test.py --input heartbeat.json --output ../spec/tests/yaml/swiftnav/sbp/system/test_MsgHeartbeat.yaml
 ```
 
+*NOTE* because the json2test file imports the local version of sbp & the build
+system of it all is a little slapdash, this command will ONLY work if called from
+inside of `libsbp/generator/` directory because the `${PROJECT_ROOT}` in the script
+declartion of json2test.py is whatever the PWD is when the command is called, and
+caching is turned off.
+
 Usage for `json2test`
 
 ```shell
-python json2test --input [PATH_TO_JSON_IN] --output [PATH_TO_YAML_OUT]
+uv -n run json2test --input [PATH_TO_JSON_IN] --output [PATH_TO_YAML_OUT]
 ```
 
 * The `msg_type` can also be provided through a CLI parameter, with `--msg-id

generator/json2test.py

@@ -1,4 +1,4 @@
-# Copyright (C) 2022 Swift Navigation Inc.
+# Copyright (C) 2024 Swift Navigation Inc.
 # Contact: https://support.swiftnav.com
 #
 # This source is subject to the license found in the file 'LICENSE' which must
@@ -7,6 +7,17 @@
 # THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
 # EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
 # WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
+#
+# /// script
+# requires-python = ">=3.12"
+# dependencies = [
+#     "jinja2 ~= 3.1",
+#     "pytest ~= 8.3",
+#     "pyyaml ~= 6.0",
+#     "sbp @ file:///${PROJECT_ROOT}/../python",
+# ]
+# ///
+
 """
 Generate test case from json input
 """
@@ -42,7 +53,7 @@ def write_test(msg, output, test_set_name="swiftnav"):
     module = msg.__class__.__module__
     name = msg.__class__.__name__
     test_msg_data = msg_reducer(msg)
-    test_data = TestSpecification.from_msg(msg, test_msg_data)
+    test_data = TestSpecification.from_msg(msg, test_msg_data, test_msg_data['name'])
     now_str = datetime.datetime.now().isoformat(" ")
     test_package = PackageTestSpecification(
         package=module,

generator/missing.py

@@ -62,7 +62,7 @@ def write_test(msg, test_set_name="swiftnav"):
     )
     filename = os.path.join(*path_parts)
     test_msg_data = msg_reducer(msg)
-    test_data = TestSpecification.from_msg(msg, test_msg_data)
+    test_data = TestSpecification.from_msg(msg, test_msg_data, test_msg_data['name'])
     now_str = datetime.datetime.now().isoformat(" ")
     test_package = PackageTestSpecification(
         package=module,

generator/sbpg/test_structs.py

@@ -86,7 +86,7 @@ class TestSpecification(object):
   """A message description to generate tests for.
   """
 
-  def __init__(self, raw_packet, msg_type, raw_json, msg, sbp, test_msg_data=None):
+  def __init__(self, raw_packet, msg_type, raw_json, msg, sbp, test_msg_data=None, msg_name=None):
     self.raw_packet = raw_packet
     self.raw_json = raw_json
     self.raw_json_obj = json.loads(raw_json)
@@ -99,7 +99,8 @@ def __init__(self, raw_packet, msg_type, raw_json, msg, sbp, test_msg_data=None)
     self.payload = base64.standard_b64decode(self.sbp['payload'])
     self.payload_as_byte_array = list(bytearray(self.payload))
     self.payload_len_for_encoding_buf = len(self.payload) if len(self.payload) > 0 else 1
-    msg_name = msg['name']
+    if msg_name is None:
+        msg_name = msg['name']
     for i in range(0, len(ACRONYMS)):
         msg_name = re.sub(ACRONYMS[i], LOWER_ACRONYMS[i], msg_name)
     self.enum_value = "Sbp" + msg_name
@@ -110,7 +111,7 @@ def __init__(self, raw_packet, msg_type, raw_json, msg, sbp, test_msg_data=None)
     self.fn_prefix = self.struct_name[:-2]
 
   @classmethod
-  def from_msg(cls, msg_instance, test_msg_data):
+  def from_msg(cls, msg_instance, test_msg_data, name):
     msg = msg_instance
     sbp = {
       "crc": "0x{:X}".format(msg.crc),
@@ -127,6 +128,7 @@ def from_msg(cls, msg_instance, test_msg_data):
       msg,
       sbp,
       test_msg_data=test_msg_data,
+      msg_name=name,
     )
 
   def __repr__(self):