add json string parsing globally

Author: GabrielBarberini

src/models/flight.py

@@ -73,6 +73,28 @@ def RETRIEVED(model_instance: type(Self)):
             )
         )
 
+    @field_validator('environment', mode='before')
+    @classmethod
+    def _coerce_environment(cls, value):
+        if isinstance(value, str):
+            try:
+                return json.loads(value)
+            except json.JSONDecodeError as exc:
+                raise ValueError(
+                    'Invalid JSON for environment payload'
+                ) from exc
+        return value
+
+    @field_validator('rocket', mode='before')
+    @classmethod
+    def _coerce_rocket(cls, value):
+        if isinstance(value, str):
+            try:
+                return json.loads(value)
+            except json.JSONDecodeError as exc:
+                raise ValueError('Invalid JSON for rocket payload') from exc
+        return value
+
 
 class FlightPartialModel(BaseModel):
     """Flight attributes required when rocket/environment are referenced."""

src/models/motor.py

@@ -1,6 +1,7 @@
+import json
 from enum import Enum
 from typing import Optional, Tuple, List, Union, Self, ClassVar, Literal
-from pydantic import model_validator
+from pydantic import model_validator, field_validator
 
 from src.models.interface import ApiBaseModel
 from src.models.sub.tanks import MotorTank
@@ -57,6 +58,18 @@ class MotorModel(ApiBaseModel):
     ] = 'nozzle_to_combustion_chamber'
     reshape_thrust_curve: Union[bool, tuple] = False
 
+    @field_validator('tanks', mode='before')
+    @classmethod
+    def _coerce_tanks(cls, value):
+        if isinstance(value, str):
+            try:
+                value = json.loads(value)
+            except json.JSONDecodeError as exc:
+                raise ValueError('Invalid JSON for tanks payload') from exc
+        if isinstance(value, dict):
+            value = [value]
+        return value
+
     @model_validator(mode='after')
     # TODO: extend guard to check motor kinds and tank kinds specifics
     def validate_motor_kind(self):

src/models/rocket.py

@@ -13,6 +13,15 @@
 )
 
 
+def _maybe_parse_json(value):
+    if isinstance(value, str):
+        try:
+            return json.loads(value)
+        except json.JSONDecodeError as exc:
+            raise ValueError('Invalid JSON payload') from exc
+    return value
+
+
 class RocketModel(ApiBaseModel):
     NAME: ClassVar = "rocket"
     METHODS: ClassVar = ("POST", "GET", "PUT", "DELETE")
@@ -40,6 +49,42 @@ class RocketModel(ApiBaseModel):
     rail_buttons: Optional[RailButtons] = None
     tail: Optional[Tail] = None
 
+    @field_validator('motor', mode='before')
+    @classmethod
+    def _coerce_motor(cls, value):
+        return _maybe_parse_json(value)
+
+    @field_validator('nose', mode='before')
+    @classmethod
+    def _coerce_nose(cls, value):
+        return _maybe_parse_json(value)
+
+    @field_validator('fins', mode='before')
+    @classmethod
+    def _coerce_fins(cls, value):
+        value = _maybe_parse_json(value)
+        if isinstance(value, dict):
+            value = [value]
+        return value
+
+    @field_validator('parachutes', mode='before')
+    @classmethod
+    def _coerce_parachutes(cls, value):
+        value = _maybe_parse_json(value)
+        if isinstance(value, dict):
+            value = [value]
+        return value
+
+    @field_validator('rail_buttons', mode='before')
+    @classmethod
+    def _coerce_rail_buttons(cls, value):
+        return _maybe_parse_json(value)
+
+    @field_validator('tail', mode='before')
+    @classmethod
+    def _coerce_tail(cls, value):
+        return _maybe_parse_json(value)
+
     @staticmethod
     def UPDATED():
         return