Exclude not critical test (#2)

* Exclude not critical test

* Add exclude-tests option

* Update documentation

* Clean forgotten print

* Improve Readme, with examples

README.rst

@@ -43,7 +43,7 @@ Add the migration linter your ``INSTALLED_APPS``:
     ]
 
 
-``python manage.py lintmigrations [GIT_COMMIT_ID] [--ignore-name-contains IGNORE_NAME_CONTAINS] [--include-apps INCLUDE_APPS [INCLUDE_APPS ...] | --exclude-apps EXCLUDE_APPS [EXCLUDE_APPS ...]] [--project-root-path DJANGO_PROJECT_FOLDER]``
+``python manage.py lintmigrations [GIT_COMMIT_ID] [--ignore-name-contains IGNORE_NAME_CONTAINS] [--include-apps INCLUDE_APPS [INCLUDE_APPS ...] | --exclude-apps EXCLUDE_APPS [EXCLUDE_APPS ...]] [--exclude-tests EXCLUDE_TESTS [EXCLUDE TESTS ...]] [--project-root-path DJANGO_PROJECT_FOLDER]``
 
 ================================================== ===========================================================================================================================
                    Parameter                                                                            Description
@@ -53,6 +53,7 @@ Add the migration linter your ``INSTALLED_APPS``:
 ``--ignore-name IGNORE_NAME [IGNORE_NAME ...]``    Ignore migrations with exactly one of these names.
 ``--include-apps INCLUDE_APPS [INCLUDE_APPS ...]`` Check only migrations that are in the specified django apps.
 ``--exclude-apps EXCLUDE_APPS [EXCLUDE_APPS ...]`` Ignore migrations that are in the specified django apps.
+``--exclude-tests EXCLUDE_TESTS [EXCLUDE TES...]`` Specify tests to be ignored (e.g. ALTER_COLUMN).
 ``--verbose or -v``                                Print more information during execution.
 ``--database DATABASE``                            Specify the database for which to generate the SQL. Defaults to *default*.
 ``--cache-path PATH``                              specify a directory that should be used to store cache-files in.
@@ -99,6 +100,52 @@ You can also ignore migrations by adding this to your migrations:
         ]
     # ...
 
+Ignoring tests
+-------------------
+
+You can also ignore tests by adding this option during execution:
+
+``python manage.py lintmigrations --exclude-tests EXCLUDE_TESTS``
+
+The tests list can be found in sql_analyzer (migration_tests):
+
+.. code-block::
+
+    migration_tests = (
+        {
+            "code": "NOT_NULL",
+            "fn": lambda sql, **kw: re.search("(?<!DROP) NOT NULL", sql)
+            and not re.search("CREATE TABLE", sql),
+            "err_msg": "NOT NULL constraint on columns",
+        },
+        {
+            "code": "DROP_COLUMN",
+            "fn": lambda sql, **kw: re.search("DROP COLUMN", sql),
+            "err_msg": "DROPPING columns",
+        },
+        {
+            "code": "RENAME_COLUMN",
+            "fn": lambda sql, **kw: re.search("ALTER TABLE .* CHANGE", sql)
+            or re.search("ALTER TABLE .* RENAME COLUMN", sql),
+            "err_msg": "RENAMING columns",
+        },
+        {
+            "code": "RENAME_TABLE",
+            "fn": lambda sql, **kw: re.search("RENAME TABLE", sql)
+            or re.search("ALTER TABLE .* RENAME TO", sql),
+            "err_msg": "RENAMING tables",
+        },
+        {
+            "code": "ALTER_COLUMN",
+            "fn": lambda sql, **kw: re.search("ALTER TABLE .* MODIFY", sql)
+            or re.search("ALTER TABLE .* ALTER COLUMN .* TYPE", sql),
+            "err_msg": (
+                "ALTERING columns (Could be backward compatible. "
+                "You may ignore this migration.)"
+            ),
+        },
+        {"code": "", "fn": has_default, "err_msg": ""},
+    )
 
 Cache
 -----

django_migration_linter/management/commands/lintmigrations.py

@@ -50,6 +50,10 @@ class Command(BaseCommand):
             "--project-root-path", type=str, nargs="?", help="django project root path"
         )
 
+        parser.add_argument(
+            "--exclude-tests", type=str, nargs="*", help="Specify tests to be ignored (e.g. ALTER_COLUMN)"
+        )
+
         cache_group = parser.add_mutually_exclusive_group(required=False)
         cache_group.add_argument(
             "--cache-path",
@@ -107,6 +111,7 @@ class Command(BaseCommand):
             ignore_name=options["ignore_name"],
             include_apps=options["include_apps"],
             exclude_apps=options["exclude_apps"],
+            exclude_tests=options["exclude_tests"],
             database=options["database"],
             cache_path=options["cache_path"],
             no_cache=options["no_cache"],

django_migration_linter/migration_linter.py

@@ -42,6 +42,7 @@ class MigrationLinter(object):
         ignore_name=None,
         include_apps=None,
         exclude_apps=None,
+        exclude_tests=None,
         database=DEFAULT_DB_ALIAS,
         cache_path=DEFAULT_CACHE_PATH,
         no_cache=False,
@@ -54,6 +55,7 @@ class MigrationLinter(object):
         self.ignore_name = ignore_name or tuple()
         self.include_apps = include_apps
         self.exclude_apps = exclude_apps
+        self.exclude_tests = exclude_tests
         self.database = database or DEFAULT_DB_ALIAS
         self.cache_path = cache_path or DEFAULT_CACHE_PATH
         self.no_cache = no_cache
@@ -118,7 +120,8 @@ class MigrationLinter(object):
             return
 
         sql_statements = self.get_sql(app_label, migration_name)
-        errors = analyse_sql_statements(sql_statements)
+        exclude_tests = self.exclude_tests or []
+        errors = analyse_sql_statements(sql_statements, exclude_tests)
 
         if not errors:
             print("OK")

django_migration_linter/sql_analyser.py

@@ -70,11 +70,11 @@ migration_tests = (
 )
 
 
-def analyse_sql_statements(sql_statements):
+def analyse_sql_statements(sql_statements, exclude_tests):
     errors = []
     for statement in sql_statements:
         for test in migration_tests:
-            if test["fn"](statement, errors=errors):
+            if test["code"] not in exclude_tests and test["fn"](statement, errors=errors):
                 logger.debug("Testing {0} -- ERROR".format(statement))
                 table_search = re.search("TABLE `([^`]*)`", statement, re.IGNORECASE)
                 col_search = re.search("COLUMN `([^`]*)`", statement, re.IGNORECASE)