Add unit tests for custom charm functionality

.github/workflows/checks.yaml

@@ -6,11 +6,15 @@ on:
       - main
   pull_request:
 
+permissions: {}
+
 jobs:
   app-checks:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
+        with:
+          persist-credentials: false
       - name: Run framework tests
         run: |
           cd dashboard
@@ -31,3 +35,19 @@ jobs:
         run: |
           cd dashboard
           make makemigrations-check
+
+  charm-tests:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          persist-credentials: false
+      - uses: astral-sh/setup-uv@cec208311dfd045dd5311c1add060b2062131d57 # v8.0.0
+      - name: Lint
+        run: |
+          cd charm
+          uvx tox run -e lint
+      - name: Unit tests
+        run: |
+          cd charm
+          uvx tox run -e unit

charm/requirements.txt

@@ -1,2 +1,2 @@
-ops ~= 2.17
+ops ~= 3.7
 paas-charm>=1.0,<2

charm/tests/unit/test_charm.py

@@ -0,0 +1,58 @@
+# Copyright 2026 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+"""Unit tests for the dashboard charm's custom functionality."""
+
+import pytest
+from ops import testing
+
+import charm
+
+_LOADDATA_CMD = ["python3", "manage.py", "loaddata", "initial_data.yaml"]
+
+
+class TestLoadSampleDataAction:
+    """Test the load-sample-data action."""
+
+    def test_load_sample_data_runs_loaddata(self):
+        """load-sample-data executes Django loaddata command."""
+        ctx = testing.Context(charm.DashboardCharm)
+        container = testing.Container(
+            "django-app",
+            can_connect=True,
+            execs={testing.Exec(_LOADDATA_CMD)},
+        )
+        state = testing.State(containers={container}, leader=True)
+
+        ctx.run(ctx.on.action("load-sample-data"), state)
+
+        exec_record = ctx.exec_history["django-app"][0]
+        assert exec_record.command == _LOADDATA_CMD
+        assert exec_record.working_dir is not None
+        assert ctx.action_results == {"result": "loaded sample data"}
+
+    def test_load_sample_data_fails_on_exec_error(self):
+        """load-sample-data action fails when the manage.py command fails."""
+        ctx = testing.Context(charm.DashboardCharm)
+        container = testing.Container(
+            "django-app",
+            can_connect=True,
+            execs={testing.Exec(_LOADDATA_CMD, return_code=1)},
+        )
+        state = testing.State(containers={container}, leader=True)
+
+        with pytest.raises(testing.ActionFailed) as exc_info:
+            ctx.run(ctx.on.action("load-sample-data"), state)
+
+        assert "unable to load sample data" in exc_info.value.message
+
+    def test_load_sample_data_fails_on_api_error(self):
+        """load-sample-data fails when manage.py isn't available."""
+        ctx = testing.Context(charm.DashboardCharm)
+        container = testing.Container("django-app", can_connect=True)
+        state = testing.State(containers={container}, leader=True)
+
+        with pytest.raises(testing.ActionFailed) as exc_info:
+            ctx.run(ctx.on.action("load-sample-data"), state)
+
+        assert "unable to load sample data" in exc_info.value.message

charm/tox.ini

@@ -4,12 +4,12 @@
 [tox]
 no_package = True
 skip_missing_interpreters = True
-env_list = format, lint, static
+env_list = format, lint
 min_version = 4.0.0
 
 [vars]
 src_path = {tox_root}/src
-;tests_path = {tox_root}/tests
+tests_path = {tox_root}/tests
 ;lib_path = {tox_root}/lib/charms/operator_name_with_underscores
 all_path = {[vars]src_path}
 
@@ -32,23 +32,27 @@ commands =
     ruff check --fix {[vars]all_path}
 
 [testenv:lint]
-description = Check code against coding style standards
+description = Check code against coding style standards and run static type checks
 deps =
     ruff
     codespell
+    pyright
+    -r {tox_root}/requirements.txt
 commands =
     # if this charm owns a lib, uncomment "lib_path" variable
     # and uncomment the following line
     # codespell {[vars]lib_path}
     codespell {tox_root}
     ruff check {[vars]all_path}
     ruff format --check --diff {[vars]all_path}
+    pyright {posargs}
 
 [testenv:unit]
 description = Run unit tests
 deps =
     pytest
     coverage[toml]
+    ops[testing]
     -r {tox_root}/requirements.txt
 commands =
     coverage run --source={[vars]src_path} \
@@ -60,14 +64,6 @@ commands =
                  {[vars]tests_path}/unit
     coverage report
 
-[testenv:static]
-description = Run static type checks
-deps =
-    pyright
-    -r {tox_root}/requirements.txt
-commands =
-    pyright {posargs}
-
 [testenv:integration]
 description = Run integration tests
 deps =