fix(docs): clarify properties key naming in documentation and tests

- Updated documentation to replace "key" with "id" in the context of component properties in `system.yml`.
- Adjusted test assertions to reflect the change from "key" to "id" for consistency with the updated documentation.
- Ensured that error messages for duplicate properties also refer to "id" instead of "key".

Author: dusanparipovic

docs/CHANGELOG.md

@@ -6,7 +6,7 @@ All notable changes to GemsPy are documented here.
 
 ### Added
 
-- **System components: `properties`** - introduces optional `properties` on components in `system.yml` (a list of `id`/`value` pairs). These are normalized into a `dict[str, str]` on the resolved `Component` (duplicate keys raise a `ValueError`).
+- **System components: `properties`** - introduces optional `properties` on components in `system.yml` (a list of `id`/`value` pairs). These are normalized into a `dict[str, str]` on the resolved `Component` (duplicate ids raise a `ValueError`).
 - **Model schema: `taxonomy-category`** - introduces optional `taxonomy-category` on models in library YAML files, exposed as `ModelSchema.taxonomy_category`.
 
 ## [0.1.0] - 2026-04-30

docs/getting-started.md

@@ -94,7 +94,7 @@ system:
     - id: G1
       model: basic.generator
       properties:
-        - key: technology
+        - id: technology
           value: nuclear
       parameters:
         - id: marginal_cost

docs/user-guide/inputs.md

@@ -44,7 +44,7 @@ parts of the study from in-memory data.
 ## System YAML: optional component `properties`
 
 In `system.yml`, each component may define an optional `properties` section as a
-list of key/value pairs:
+list of id/value pairs:
 
 ~~~ yaml
 system:
@@ -59,7 +59,7 @@ system:
 ~~~
 
 At resolution time (`resolve_system` / `load_study`), this list is normalized into
-a `dict[str, str]` stored on the resolved `Component`. Duplicate keys are rejected.
+a `dict[str, str]` stored on the resolved `Component`. Duplicate ids are rejected.
 
 ### Loading the library and the system
 

tests/unittests/system_parsing/test_components_parsing.py

@@ -124,8 +124,8 @@ def test_parse_yaml_components_properties_optional_and_normalized() -> None:
     raw = props_by_id["nuclear_1"]
     assert isinstance(raw, list) and len(raw) == 2
     assert [p.model_dump() for p in raw] == [
-        {"key": "technology", "value": "nuclear"},
-        {"key": "company", "value": "rhonepower"},
+        {"id": "technology", "value": "nuclear"},
+        {"id": "company", "value": "rhonepower"},
     ]
 
 
@@ -174,7 +174,7 @@ def test_resolve_component_properties_duplicate_keys_raises(
 ) -> None:
     system = parse_yaml_components(io.StringIO(_SYSTEM_WITH_PROPERTIES_DUPLICATE_KEYS))
     lib_dict = resolve_library([input_library])
-    with pytest.raises(ValueError, match="duplicate properties key"):
+    with pytest.raises(ValueError, match="duplicate properties id"):
         resolve_system(system, lib_dict)
 
 

tests/unittests/system_parsing/test_systemschema_from_file.py

@@ -18,9 +18,9 @@ def test_parse_yaml_components_from_file_parses_properties_list(tmp_path: Path)
     - id: nuclear_1
       model: basic.generator
       properties:
-        - key: technology
+        - id: technology
           value: nuclear
-        - key: company
+        - id: company
           value: rhonepower
 """
     p = tmp_path / "system.yml"
@@ -31,8 +31,8 @@ def test_parse_yaml_components_from_file_parses_properties_list(tmp_path: Path)
     assert comp.id == "nuclear_1"
     assert comp.properties is not None
     assert [x.model_dump() for x in comp.properties] == [
-        {"key": "technology", "value": "nuclear"},
-        {"key": "company", "value": "rhonepower"},
+        {"id": "technology", "value": "nuclear"},
+        {"id": "company", "value": "rhonepower"},
     ]