Factor out filtering of database configuration to function with tests (#228).

borgmatic/commands/borgmatic.py

@@ -285,18 +285,9 @@ def run_actions(
             )
 
             # Map the restore names or detected dumps to the corresponding database configurations.
-            # TODO: Need to filter restore_names by database type? Maybe take a database --type argument to disambiguate.
-            restore_databases = {
-                hook_name: list(
-                    dump.get_database_configurations(
-                        hooks.get(hook_name),
-                        restore_names
-                        or dump.get_database_names_from_dumps(dump_patterns['hook_name']),
-                    )
-                )
-                for hook_name in dump.DATABASE_HOOK_NAMES
-                if hook_name in hooks
-            }
+            restore_databases = dump.get_per_hook_database_configurations(
+                hooks, restore_names, dump_patterns
+            )
 
             # Finally, restore the databases and cleanup the dumps.
             dispatch.call_hooks(

borgmatic/hooks/dump.py

@@ -100,3 +100,32 @@ def get_database_configurations(databases, names):
                 name
             )
         )
+
+
+def get_per_hook_database_configurations(hooks, names, dump_patterns):
+    '''
+    Given the hooks configuration dict as per the configuration schema, a sequence of database
+    names to restore, and a dict from database hook name to glob patterns for matching dumps,
+    filter down the configuration for just the named databases.
+
+    If there are no named databases given, then find the corresponding database dumps on disk and
+    use the database names from their filenames. Additionally, if a database configuration is named
+    "all", project out that configuration for each named database.
+
+    Return the results as a dict from database hook name to a sequence of database configuration
+    dicts for that database type.
+
+    Raise ValueError if one of the database names cannot be matched to a database in borgmatic's
+    database configuration.
+    '''
+    # TODO: Need to filter names by database type? Maybe take a database --type argument to disambiguate.
+    return {
+        hook_name: list(
+            get_database_configurations(
+                hooks.get(hook_name),
+                names or get_database_names_from_dumps(dump_patterns[hook_name]),
+            )
+        )
+        for hook_name in DATABASE_HOOK_NAMES
+        if hook_name in hooks
+    }

tests/unit/hooks/test_dump.py

@@ -99,3 +99,33 @@ def test_get_database_configurations_with_unknown_database_name_raises():
 
     with pytest.raises(ValueError):
         list(module.get_database_configurations(databases, ('foo', 'bar')))
+
+
+def test_get_per_hook_database_configurations_partitions_by_hook():
+    hooks = {'postgresql_databases': [flexmock()]}
+    names = ('foo', 'bar')
+    dump_patterns = flexmock()
+    expected_config = {'postgresql_databases': [flexmock()]}
+    flexmock(module).should_receive('get_database_configurations').with_args(
+        hooks['postgresql_databases'], names
+    ).and_return(expected_config['postgresql_databases'])
+
+    config = module.get_per_hook_database_configurations(hooks, names, dump_patterns)
+
+    assert config == expected_config
+
+
+def test_get_per_hook_database_configurations_defaults_to_detected_database_names():
+    hooks = {'postgresql_databases': [flexmock()]}
+    names = ()
+    detected_names = flexmock()
+    dump_patterns = {'postgresql_databases': [flexmock()]}
+    expected_config = {'postgresql_databases': [flexmock()]}
+    flexmock(module).should_receive('get_database_names_from_dumps').and_return(detected_names)
+    flexmock(module).should_receive('get_database_configurations').with_args(
+        hooks['postgresql_databases'], detected_names
+    ).and_return(expected_config['postgresql_databases'])
+
+    config = module.get_per_hook_database_configurations(hooks, names, dump_patterns)
+
+    assert config == expected_config