add unit test for checking updates to stencils

src/unittest/mascara/1_process_only_modified_3/10-templates/ab.jinja

@@ -0,0 +1,18 @@
+{%- import 'stencils/common.jinja' as common -%}
+
+{# -------------------------------------------------------------------------- #}
+
+{%- set all_variables = {
+  'A': {
+    'repeats': 5,
+  },
+  'b': {
+    'repeats': 3,
+  },
+} -%}
+
+{# -------------------------------------------------------------------------- #}
+
+{{- common.start_new_file('ab.txt') -}}
+
+{{- common.render(all_variables) -}}

src/unittest/mascara/1_process_only_modified_3/10-templates/cd.jinja

@@ -0,0 +1,18 @@
+{%- import 'stencils/common.jinja' as common -%}
+
+{# -------------------------------------------------------------------------- #}
+
+{%- set all_variables = {
+  'c': {
+    'repeats': 2,
+  },
+  'D': {
+    'repeats': 10,
+  },
+} -%}
+
+{# -------------------------------------------------------------------------- #}
+
+{{- common.start_new_file('cd.txt') -}}
+
+{{- common.render(all_variables) -}}

src/unittest/mascara/1_process_only_modified_3/10-templates_updated/stencils/common.jinja

@@ -0,0 +1,19 @@
+{# Create a new file by inserting a special string into the output. #}
+{# This allows you to create multiple files from a single template. #}
+
+{%- macro start_new_file(filename) %}
+### New file: {{ filename }}
+### Content:
+{% endmacro -%}
+
+{# -------------------------------------------------------------------------- #}
+
+{% macro render(variables) %}
+{% for variable_key in variables -%}
+{%- for n in range(variables[variable_key].repeats) -%}
+{{ variable_key }}
+{{- '.' if not loop.last }}
+{%- endfor %}
+
+{% endfor %}
+{% endmacro %}

src/unittest/mascara/1_process_only_modified_3/30-expected/ab.txt

@@ -0,0 +1,2 @@
+AAAAA
+bbb

src/unittest/mascara/1_process_only_modified_3/30-expected/cd.txt

@@ -0,0 +1,2 @@
+cc
+DDDDDDDDDD

src/unittest/mascara/1_process_only_modified_3/30-expected_updated/ab.txt

@@ -0,0 +1,2 @@
+A.A.A.A.A
+b.b.b

src/unittest/mascara/1_process_only_modified_3/30-expected_updated/cd.txt

@@ -0,0 +1,2 @@
+c.c
+D.D.D.D.D.D.D.D.D.D

src/unittest/test_mascara.py

@@ -117,7 +117,6 @@ def modify_file(partial_file_path):
         assert saved_files == 2
 
 
-
     # She updates a template and checks whether a partial run updates the
     # respective output file.
     def test_process_only_modified_2(self, tmp_path):
@@ -173,6 +172,62 @@ def update_file(partial_file_path):
         assert saved_files == 1
 
 
+    # Mascara also checks whether updating a stencil changes any output files in
+    # a partial run. It does not.
+    def test_process_only_modified_3(self, tmp_path):
+
+        def convenience_run(partial_run, matching):
+            _, saved_files = self.run(
+                config_path,
+                process_only_modified=partial_run)
+
+            if matching:
+                self.compare_directories(config)
+            else:
+                with pytest.raises(AssertionError):
+                    self.compare_directories(config)
+
+            return saved_files
+
+
+        def update_file(partial_file_path):
+            input_path = os.path.join(tmp_path, partial_file_path)
+            output_path = input_path.replace('_updated', '')
+
+            shutil.copyfile(input_path, output_path)
+
+        # ---------------------------------------------------------------------
+
+        config = {
+            'stencil_dir_name': 'stencils',
+        }
+
+        config_path = self.create_config(
+            config, tmp_path, 'settings.json')
+
+        unit_test_directory = '1_process_only_modified_3'
+
+        with open(config_path, mode='r') as f:
+            config = json.load(f)
+
+        # set up StempelWerk and execute full run
+        _, saved_files = self.run_and_compare(config_path, unit_test_directory)
+        assert saved_files == 2
+
+        update_file('10-templates_updated/stencils/common.jinja')
+
+        # partial run does not check for changed stencils
+        saved_files = convenience_run(partial_run=True, matching=True)
+        assert saved_files == 0
+
+        update_file('30-expected_updated/ab.txt')
+        update_file('30-expected_updated/cd.txt')
+
+        # full run applies changed stencils
+        saved_files = convenience_run(partial_run=False, matching=True)
+        assert saved_files == 2
+
+
     # Mascara wants to get become more proficient in Python [ahem] and checks
     # whether StempelWerk is really as lean as its developer promises.
     def test_lean_template_removal(self, tmp_path):