Add tier attribute tests

tests/data/codelist/tier_attribute/invalid/tag_fuel.yaml

@@ -0,0 +1,4 @@
+- Fuel:
+  - Coal:
+      description: coal
+      tier: +1

tests/data/codelist/tier_attribute/invalid/variables.yaml

@@ -0,0 +1,11 @@
+- Primary Energy:
+    description: Total primary energy consumption
+    unit: EJ/yr
+- Primary Energy|{Fuel}:
+    description: Primary energy consumption of {Fuel}
+    unit: EJ/yr
+    tier: 1
+- Share|{Fuel}:
+    description: Share of {Fuel} in the total primary energy mix
+    unit: '%'
+    tier: 2

tests/data/codelist/tier_attribute/valid/tag_fuel.yaml

@@ -0,0 +1,4 @@
+- Fuel:
+  - Coal:
+      description: coal
+      tier: ^1

tests/data/codelist/tier_attribute/valid/tag_sector.yaml

@@ -0,0 +1,6 @@
+- Sector:
+    - Agriculture:
+        description: agriculture sector including fishing
+        tier: ^1
+    - Industry:
+        description: industrial sector excluding non-energy use (e.g.feedstocks)

tests/data/codelist/tier_attribute/valid/variables.yaml

@@ -0,0 +1,11 @@
+- Primary Energy:
+    description: Total primary energy consumption
+    unit: EJ/yr
+- Primary Energy|{Fuel}|{Sector}:
+    description: Primary energy consumption of {Fuel}
+    unit: EJ/yr
+    tier: 1
+- Share|{Fuel}:
+    description: Share of {Fuel} in the total primary energy mix
+    unit: '%'
+    tier: 2

tests/test_codelist.py

@@ -147,6 +147,36 @@ def test_tags_in_list_attributes():
             assert getattr(code[code_name], attr_name) == value
 
 
+def test_tier_attribute_in_tags():
+    """Check for tier attribute functionality ('tier' in tags upgrade CodeList's):
+    1) 'tier' is not added when not present in Code or tag;
+    2) 'tier' is/are upgraded when present in Code and matching tag(s)
+    3) 'tier' in tag only accepts two values: '^1' and '^2'"""
+    code_list = VariableCodeList.from_directory(
+        "variable", MODULE_TEST_DATA_DIR / "tier_attribute" / "valid"
+    )
+    # check tier attribute is upgraded correctly
+    assert code_list["Share|Coal"].tier == 3
+    assert code_list["Primary Energy|Coal|Industry"].tier == 2
+
+    # check multiple tier attributes upgrade cumulatively
+    assert code_list["Primary Energy|Coal|Agriculture"].tier == 3
+
+    # check codes without tier attributes don't change
+    assert not code_list["Primary Energy"].tier
+
+
+def test_misformatted_tier_fails():
+    """Check misformatted 'tier' attributes raise errors"""
+
+    match = "Tag 'Primary Energy|Coal' includes misformatted 'tier' attribute. "
+    "Allowed values for tier attributes in tags are '^1' or '^2'."
+    with pytest.raises(ValueError, match=match):
+        VariableCodeList.from_directory(
+            "variable", MODULE_TEST_DATA_DIR / "tier_attribute" / "invalid"
+        )
+
+
 def test_region_codelist():
     """Check replacing top-level hierarchy of yaml file as attribute for regions"""
     code = RegionCodeList.from_directory(