Remove Unions (#137)

* removed union response models from getters of surface normals and reference vectors

* removed CoordinateResponse object and separated into other response models

src/diffcalc_api/models/response.py

@@ -1,5 +1,5 @@
 """Pydantic models relating to all endpoint responses."""
-from typing import Dict, List, Union
+from typing import Dict, List
 
 from pydantic import BaseModel
 
@@ -46,14 +46,31 @@ class DiffractorAnglesResponse(BaseModel):
     payload: List[Dict[str, float]]
 
 
-class CoordinateResponse(BaseModel):
-    """Coordinate response model.
+class SphericalResponse(BaseModel):
+    """Spherical coordinate response model.
 
-    Returns coordinates, in three dimensions, for a given coordinate system.
-    Supported systems include spherical coordinates, reciprocal and real space.
+    Returns a payload in spherical coordinates.
     """
 
-    payload: Union[SphericalCoordinates, HklModel, XyzModel]
+    payload: SphericalCoordinates
+
+
+class ReciprocalSpaceResponse(BaseModel):
+    """Reciprocal space coordinate response model.
+
+    Returns a payload in reciprocal space (hkl) coordinates.
+    """
+
+    payload: HklModel
+
+
+class RealSpaceResponse(BaseModel):
+    """Reciprocal space coordinate response model.
+
+    Returns a payload in xyz coordinates.
+    """
+
+    payload: XyzModel
 
 
 class MiscutResponse(BaseModel):

src/diffcalc_api/routes/hkl.py

@@ -7,8 +7,8 @@
 from diffcalc_api.errors.hkl import InvalidSolutionBoundsError
 from diffcalc_api.models.hkl import SolutionConstraints
 from diffcalc_api.models.response import (
-    CoordinateResponse,
     DiffractorAnglesResponse,
+    ReciprocalSpaceResponse,
     ScanResponse,
 )
 from diffcalc_api.models.ub import HklModel, PositionModel
@@ -60,7 +60,7 @@ async def lab_position_from_miller_indices(
     return DiffractorAnglesResponse(payload=positions)
 
 
-@router.get("/{name}/position/hkl", response_model=CoordinateResponse)
+@router.get("/{name}/position/hkl", response_model=ReciprocalSpaceResponse)
 async def miller_indices_from_lab_position(
     name: str,
     pos: PositionModel = Depends(),
@@ -78,12 +78,12 @@ async def miller_indices_from_lab_position(
         collection: collection within which the hkl object resides.
 
     Returns:
-        CoordinateResponse containing the miller indices.
+        ReciprocalSpaceResponse containing the miller indices.
     """
     hkl = await service.miller_indices_from_lab_position(
         name, pos, wavelength, store, collection
     )
-    return CoordinateResponse(payload=hkl)
+    return ReciprocalSpaceResponse(payload=hkl)
 
 
 @router.get("/{name}/scan/hkl", response_model=ScanResponse)

src/diffcalc_api/routes/ub.py

@@ -1,6 +1,6 @@
 """Endpoints relating to the management of setting up the UB calculation."""
 
-from typing import List, Optional, Union
+from typing import List, Optional, cast
 
 from fastapi import APIRouter, Body, Depends, Query
 
@@ -12,9 +12,10 @@
 from diffcalc_api.examples import ub as examples
 from diffcalc_api.models.response import (
     ArrayResponse,
-    CoordinateResponse,
     InfoResponse,
     MiscutResponse,
+    ReciprocalSpaceResponse,
+    SphericalResponse,
     StringResponse,
 )
 from diffcalc_api.models.ub import (
@@ -611,7 +612,7 @@ async def set_miller_surface_normal(
     )
 
 
-@router.get("/{name}/nphi", response_model=Union[ArrayResponse, InfoResponse])
+@router.get("/{name}/nphi", response_model=ArrayResponse)
 async def get_lab_reference_vector(
     name: str,
     store: HklCalcStore = Depends(get_store),
@@ -625,20 +626,20 @@ async def get_lab_reference_vector(
         collection: collection within which the hkl object resides.
 
     Returns:
-        ArrayResponse with the vector, or
-        InfoResponse if it doesn't exist
+        ArrayResponse with the vector. If it doesn't exist, a null vector is returned.
 
     """
-    lab_vector: Optional[List[List[float]]] = await service.get_lab_reference_vector(
+    vector: Optional[List[List[float]]] = await service.get_lab_reference_vector(
         name, store, collection
     )
-    if lab_vector is not None:
-        return ArrayResponse(payload=lab_vector)
-    else:
-        return InfoResponse(message="This vector does not exist.")
 
+    if vector is None:
+        return ArrayResponse(payload=[[]])
 
-@router.get("/{name}/nhkl", response_model=Union[ArrayResponse, InfoResponse])
+    return ArrayResponse(payload=vector)
+
+
+@router.get("/{name}/nhkl", response_model=ArrayResponse)
 async def get_miller_reference_vector(
     name: str,
     store: HklCalcStore = Depends(get_store),
@@ -652,20 +653,18 @@ async def get_miller_reference_vector(
         collection: collection within which the hkl object resides.
 
     Returns:
-        ArrayResponse with the vector, or
-        InfoResponse if it doesn't exist
+        ArrayResponse with the vector. By default, newly instantiated
+        Hkl objects always have this vector.
 
     """
-    lab_vector: Optional[List[List[float]]] = await service.get_miller_reference_vector(
+    vector: Optional[List[List[float]]] = await service.get_miller_reference_vector(
         name, store, collection
     )
-    if lab_vector is not None:
-        return ArrayResponse(payload=lab_vector)
-    else:
-        return InfoResponse(message="This vector does not exist.")
 
+    return ArrayResponse(payload=cast(List[List[float]], vector))
 
-@router.get("/{name}/surface/nphi", response_model=Union[ArrayResponse, InfoResponse])
+
+@router.get("/{name}/surface/nphi", response_model=ArrayResponse)
 async def get_lab_surface_normal(
     name: str,
     store: HklCalcStore = Depends(get_store),
@@ -679,20 +678,17 @@ async def get_lab_surface_normal(
         collection: collection within which the hkl object resides.
 
     Returns:
-        ArrayResponse with the vector, or
-        InfoResponse if it doesn't exist
+        ArrayResponse with the vector. By default, newly instantiated
+        Hkl objects always have this vector.
 
     """
-    lab_vector: Optional[List[List[float]]] = await service.get_lab_surface_normal(
+    vector: Optional[List[List[float]]] = await service.get_lab_surface_normal(
         name, store, collection
     )
-    if lab_vector is not None:
-        return ArrayResponse(payload=lab_vector)
-    else:
-        return InfoResponse(message="This vector does not exist.")
+    return ArrayResponse(payload=cast(List[List[float]], vector))
 
 
-@router.get("/{name}/surface/nhkl", response_model=Union[ArrayResponse, InfoResponse])
+@router.get("/{name}/surface/nhkl", response_model=ArrayResponse)
 async def get_miller_surface_normal(
     name: str,
     store: HklCalcStore = Depends(get_store),
@@ -706,25 +702,22 @@ async def get_miller_surface_normal(
         collection: collection within which the hkl object resides.
 
     Returns:
-        ArrayResponse with the vector, or
-        InfoResponse if it doesn't exist
+        ArrayResponse with the vector. By default, newly instantiated
+        Hkl objects always have this vector.
 
     """
-    lab_vector: Optional[List[List[float]]] = await service.get_miller_surface_normal(
+    vector: Optional[List[List[float]]] = await service.get_miller_surface_normal(
         name, store, collection
     )
-    if lab_vector is not None:
-        return ArrayResponse(payload=lab_vector)
-    else:
-        return InfoResponse(message="This vector does not exist.")
+    return ArrayResponse(payload=cast(List[List[float]], vector))
 
 
 #######################################################################################
 #                           Vector Calculations in HKL Space                          #
 #######################################################################################
 
 
-@router.get("/{name}/vector", response_model=CoordinateResponse)
+@router.get("/{name}/vector", response_model=ReciprocalSpaceResponse)
 async def calculate_vector_from_hkl_and_offset(
     name: str,
     hkl_ref: HklModel = Depends(),
@@ -747,18 +740,20 @@ async def calculate_vector_from_hkl_and_offset(
         collection: collection within which the hkl object resides.
 
     Returns:
-        CoordinateResponse
+        ReciprocalSpaceResponse
         Containing the calculated reciprocal space vector as h, k, l indices.
 
     """
     vector = await service.calculate_vector_from_hkl_and_offset(
         name, hkl_ref, polar_angle, azimuth_angle, store, collection
     )
 
-    return CoordinateResponse(payload=HklModel(h=vector[0], k=vector[1], l=vector[2]))
+    return ReciprocalSpaceResponse(
+        payload=HklModel(h=vector[0], k=vector[1], l=vector[2])
+    )
 
 
-@router.get("/{name}/offset", response_model=CoordinateResponse)
+@router.get("/{name}/offset", response_model=SphericalResponse)
 async def calculate_offset_from_vector_and_hkl(
     name: str,
     h1: float = Query(..., example=0.0),
@@ -787,7 +782,7 @@ async def calculate_offset_from_vector_and_hkl(
         collection: collection within which the hkl object resides.
 
     Returns:
-        CoordinateResponse
+        SphericalResponse
         The offset, in spherical coordinates, between the two reciprocal space vectors,
         containing the polar angle, azimuth angle and magnitude between them.
 
@@ -799,7 +794,7 @@ async def calculate_offset_from_vector_and_hkl(
         name, hkl_offset, hkl_ref, store, collection
     )
 
-    return CoordinateResponse(
+    return SphericalResponse(
         payload=SphericalCoordinates(
             polar_angle=vector[0], azimuth_angle=vector[1], magnitude=vector[2]
         )

tests/test_ubcalc.py

@@ -476,6 +476,15 @@ def test_get_and_set_reference_vectors_hkl(
     )
 
 
+def test_get_reference_vectors_for_null_vectors():
+    ubcalc = UBCalculation()
+    hkl = HklCalculation(ubcalc, Constraints())
+    client = Client(hkl).client
+
+    response = client.get("/ub/test/nphi?collection=B07")
+    assert literal_eval(response.content.decode())["payload"] == [[]]
+
+
 def test_calculate_vector_from_hkl_and_offset():
     ubcalc = UBCalculation()
     ubcalc.UB = np.identity(3)