feat: print message if no wavelength info in config; clarify test comments on loading vs validation

Author: yucongalicechen

news/wavelength-config.rst

@@ -1,6 +1,6 @@
 **Added:**
 
-* Functionality to allow users to specify wavelength or anode type in a diffpy config file.
+* Functionality to read wavelength and anode type directly from a diffpy configuration file.
 
 **Changed:**
 

src/diffpy/labpdfproc/tools.py

@@ -160,9 +160,11 @@ def set_input_lists(args):
     return args
 
 
-def _load_wavelength_from_config_file(args):
+def load_wavelength_from_config_file(args):
     """Load wavelength and anode type from config files.
-    It takes cli inputs first, and local config, and then global config.
+
+    It prioritizes values in the following order:
+    1. cli inputs, 2. local config file, 3. global config file.
 
     Parameters
     ----------
@@ -174,16 +176,33 @@ def _load_wavelength_from_config_file(args):
     args : argparse.Namespace
         The updated arguments with the updated wavelength and anode type.
     """
-    if args.wavelength or args.anode_type:
-        return args
     global_config = _load_config(Path().home() / "diffpyconfig.json")
     local_config = _load_config(Path().cwd() / "diffpyconfig.json")
-    if local_config:
-        args.wavelength = local_config.get("wavelength")
-        args.anode_type = local_config.get("anode_type")
-    elif global_config:
-        args.wavelength = global_config.get("wavelength")
-        args.anode_type = global_config.get("anode_type")
+    local_has_data = local_config and (
+        "wavelength" in local_config or "anode_type" in local_config
+    )
+    global_has_data = global_config and (
+        "wavelength" in global_config or "anode_type" in global_config
+    )
+    if not local_has_data and not global_has_data:
+        print(
+            "No configuration file was found containing information "
+            "about the wavelength or anode type. \n"
+            "You can add the wavelength or anode type "
+            "to a configuration file on the current computer "
+            "and it will be automatically associated with "
+            "subsequent diffpy data by default. \n"
+            "You will only have to do that once. \n"
+            "For more information, please refer to www.diffpy.org/"
+            "diffpy.labpdfproc/examples/toolsexample.html"
+        )
+
+    if args.wavelength or args.anode_type:
+        return args
+    config = local_config if local_has_data else global_config
+    if config:
+        args.wavelength = args.wavelength or config.get("wavelength")
+        args.anode_type = args.anode_type or config.get("anode_type")
     return args
 
 
@@ -202,7 +221,7 @@ def set_wavelength(args):
     ------
     ValueError
         Raised if:
-        (1) neither wavelength or anode type is provided,
+        (1) neither wavelength or anode type is provided
             and xtype is not the two-theta grid,
         (2) both are provided,
         (3) anode_type is not one of the known sources,
@@ -213,7 +232,7 @@ def set_wavelength(args):
     args : argparse.Namespace
         The updated arguments with the wavelength.
     """
-    args = _load_wavelength_from_config_file(args)
+    args = load_wavelength_from_config_file(args)
     if args.wavelength is None and args.anode_type is None:
         if args.xtype not in ANGLEQUANTITIES:
             raise ValueError(

tests/test_tools.py

@@ -7,12 +7,12 @@
 
 from diffpy.labpdfproc.labpdfprocapp import get_args
 from diffpy.labpdfproc.tools import (
-    _load_wavelength_from_config_file,
     known_sources,
     load_metadata,
     load_package_info,
     load_user_info,
     load_user_metadata,
+    load_wavelength_from_config_file,
     preprocessing_args,
     set_input_lists,
     set_mud,
@@ -200,9 +200,13 @@ def test_set_output_directory_bad(user_filesystem):
 @pytest.mark.parametrize(
     "inputs, expected",
     [
-        # Test when only a home config file exists (no local config file),
-        # expect to return args if wavelength or anode type is specified,
-        # otherwise update args with values from the home config file.
+        # Test with only a home config file (no local config),
+        # expect to return values directly from args
+        # if either wavelength or anode type is specified,
+        # otherwise update args with values from the home config file
+        # (wavelength=0.3, no anode type).
+        # This test only checks loading behavior,
+        # not value validation (which is handled by `set_wavelength`).
         # C1: no args, expect to update arg values from home config
         ([""], {"wavelength": 0.3, "anode_type": None}),
         # C2: wavelength provided, expect to return args unchanged
@@ -227,7 +231,7 @@ def test_load_wavelength_from_config_file_with_home_conf_file(
 
     cli_inputs = ["2.5", "data.xy"] + inputs
     actual_args = get_args(cli_inputs)
-    actual_args = _load_wavelength_from_config_file(actual_args)
+    actual_args = load_wavelength_from_config_file(actual_args)
     assert actual_args.wavelength == expected["wavelength"]
     assert actual_args.anode_type == expected["anode_type"]
 
@@ -236,9 +240,13 @@ def test_load_wavelength_from_config_file_with_home_conf_file(
     "inputs, expected",
     [
         # Test when a local config file exists,
-        # expect to return args if wavelength or anode type is specified,
-        # otherwise update args with values from the home config file.
+        # expect to return values directly from args
+        # if either wavelength or anode type is specified,
+        # otherwise update args with values from the local config file
+        # (wavelength=0.6, no anode type).
         # Results should be the same whether if the home config exists.
+        # This test only checks loading behavior,
+        # not value validation (which is handled by `set_wavelength`).
         # C1: no args, expect to update arg values from local config
         ([""], {"wavelength": 0.6, "anode_type": None}),
         # C2: wavelength provided, expect to return args unchanged
@@ -266,7 +274,7 @@ def test_load_wavelength_from_config_file_with_local_conf_file(
 
     cli_inputs = ["2.5", "data.xy"] + inputs
     actual_args = get_args(cli_inputs)
-    actual_args = _load_wavelength_from_config_file(actual_args)
+    actual_args = load_wavelength_from_config_file(actual_args)
     assert actual_args.wavelength == expected["wavelength"]
     assert actual_args.anode_type == expected["anode_type"]
 
@@ -282,6 +290,8 @@ def test_load_wavelength_from_config_file_with_local_conf_file(
     [
         # Test when no config files exist,
         # expect to return args without modification.
+        # This test only checks loading behavior,
+        # not value validation (which is handled by `set_wavelength`).
         # C1: no args
         ([""], {"wavelength": None, "anode_type": None}),
         # C1: wavelength provided
@@ -307,7 +317,7 @@ def test_load_wavelength_from_config_file_without_conf_files(
 
     cli_inputs = ["2.5", "data.xy"] + inputs
     actual_args = get_args(cli_inputs)
-    actual_args = _load_wavelength_from_config_file(actual_args)
+    actual_args = load_wavelength_from_config_file(actual_args)
     assert actual_args.wavelength == expected["wavelength"]
     assert actual_args.anode_type == expected["anode_type"]