GH-15742: added db health check method in app (#15752)

app/app_test.go

@@ -473,3 +473,27 @@ func TestDoEmojisPermissionsMigration(t *testing.T) {
 	sort.Strings(systemAdmin2.Permissions)
 	assert.Equal(t, expectedSystemAdmin, systemAdmin2.Permissions, fmt.Sprintf("'%v' did not have expected permissions", model.SYSTEM_ADMIN_ROLE_ID))
 }
+
+func TestDBHealthCheckWriteAndDelete(t *testing.T) {
+	th := Setup(t)
+	defer th.TearDown()
+
+	expectedKey := "health_check_" + th.App.GetClusterId()
+	assert.Equal(t, expectedKey, th.App.dbHealthCheckKey())
+
+	_, err := th.App.Srv().Store.System().GetByName(expectedKey)
+	assert.NotNil(t, err)
+
+	err = th.App.DBHealthCheckWrite()
+	assert.Nil(t, err)
+
+	systemVal, err := th.App.Srv().Store.System().GetByName(expectedKey)
+	assert.Nil(t, err)
+	assert.NotNil(t, systemVal)
+
+	err = th.App.DBHealthCheckDelete()
+	assert.Nil(t, err)
+
+	_, err = th.App.Srv().Store.System().GetByName(expectedKey)
+	assert.NotNil(t, err)
+}