Raise when unsupported db vendor, and add option to specify SQL analyser

django_migration_linter/management/commands/lintmigrations.py

@@ -10,6 +10,7 @@ from django.core.management.base import BaseCommand
 
 from ...constants import __version__
 from ...migration_linter import MessageType, MigrationLinter
+from ...sql_analyser.analyser import ANALYSER_STRING_MAPPING
 from ..utils import register_linting_configuration_options
 
 CONFIG_NAME = "django_migration_linter"
@@ -127,6 +128,12 @@ class Command(BaseCommand):
             choices=MessageType.values(),
             help="don't print linting messages to stdout",
         )
+        parser.add_argument(
+            "--sql-analyser",
+            nargs="?",
+            choices=list(ANALYSER_STRING_MAPPING.keys()),
+            help="select the SQL analyser",
+        )
         register_linting_configuration_options(parser)
 
     def handle(self, *args, **options):
@@ -167,6 +174,7 @@ class Command(BaseCommand):
             quiet=options["quiet"],
             warnings_as_errors=options["warnings_as_errors"],
             no_output=options["verbosity"] == 0,
+            analyser_string=options["sql_analyser"],
         )
         linter.lint_all_migrations(
             app_label=options["app_label"],

django_migration_linter/migration_linter.py

@@ -20,7 +20,7 @@ from .constants import (
     EXPECTED_DATA_MIGRATION_ARGS,
 )
 from .operations import IgnoreMigration
-from .sql_analyser import analyse_sql_statements
+from .sql_analyser import analyse_sql_statements, get_sql_analyser_class
 from .utils import clean_bytes_to_str, get_migration_abspath, split_migration_path
 
 logger = logging.getLogger("django_migration_linter")
@@ -57,6 +57,7 @@ class MigrationLinter(object):
         quiet=None,
         warnings_as_errors=False,
         no_output=False,
+        analyser_string=None,
     ):
         # Store parameters and options
         self.django_path = path
@@ -75,6 +76,10 @@ class MigrationLinter(object):
         self.quiet = quiet or []
         self.warnings_as_errors = warnings_as_errors
         self.no_output = no_output
+        self.sql_analyser_class = get_sql_analyser_class(
+            settings.DATABASES[self.database]["ENGINE"],
+            analyser_string=analyser_string,
+        )
 
         # Initialise counters
         self.reset_counters()
@@ -161,8 +166,8 @@ class MigrationLinter(object):
 
         sql_statements = self.get_sql(app_label, migration_name)
         errors, ignored, warnings = analyse_sql_statements(
+            self.sql_analyser_class,
             sql_statements,
-            settings.DATABASES[self.database]["ENGINE"],
             self.exclude_migration_tests,
         )
 
@@ -620,8 +625,8 @@ class MigrationLinter(object):
                 sql_statements.append(runsql.sql)
 
             sql_errors, sql_ignored, sql_warnings = analyse_sql_statements(
+                self.sql_analyser_class,
                 sql_statements,
-                settings.DATABASES[self.database]["ENGINE"],
                 self.exclude_migration_tests,
             )
             if sql_errors:
@@ -650,8 +655,8 @@ class MigrationLinter(object):
                 sql_statements.append(runsql.reverse_sql)
 
             sql_errors, sql_ignored, sql_warnings = analyse_sql_statements(
+                self.sql_analyser_class,
                 sql_statements,
-                settings.DATABASES[self.database]["ENGINE"],
                 self.exclude_migration_tests,
             )
             if sql_errors:

django_migration_linter/sql_analyser/__init__.py

@@ -3,4 +3,4 @@ from .mysql import MySqlAnalyser  # noqa
 from .postgresql import PostgresqlAnalyser  # noqa
 from .sqlite import SqliteAnalyser  # noqa
 
-from .analyser import analyse_sql_statements  # noqa isort:skip
+from .analyser import analyse_sql_statements, get_sql_analyser_class  # noqa isort:skip

django_migration_linter/sql_analyser/analyser.py

@@ -1,7 +1,6 @@
 import logging
 
 from django_migration_linter.sql_analyser import (
-    BaseAnalyser,
     MySqlAnalyser,
     PostgresqlAnalyser,
     SqliteAnalyser,
@@ -9,8 +8,28 @@ from django_migration_linter.sql_analyser import (
 
 logger = logging.getLogger("django_migration_linter")
 
+ANALYSER_STRING_MAPPING = {
+    "sqlite": SqliteAnalyser,
+    "mysql": MySqlAnalyser,
+    "postgresql": PostgresqlAnalyser,
+}
 
-def get_sql_analyser(database_vendor, exclude_migration_tests=None):
+
+def get_sql_analyser_class(database_vendor, analyser_string=None):
+    if analyser_string:
+        return get_sql_analyser_from_string(analyser_string)
+    return get_sql_analyser_class_from_db_vendor(database_vendor)
+
+
+def get_sql_analyser_from_string(analyser_string):
+    if analyser_string not in ANALYSER_STRING_MAPPING:
+        raise ValueError(
+            "Unknown SQL analyser. Known values: {}".format(analyser_string.keys())
+        )
+    return ANALYSER_STRING_MAPPING[analyser_string]
+
+
+def get_sql_analyser_class_from_db_vendor(database_vendor):
     if "mysql" in database_vendor:
         sql_analyser_class = MySqlAnalyser
     elif "postgre" in database_vendor:
@@ -18,15 +37,15 @@ def get_sql_analyser(database_vendor, exclude_migration_tests=None):
     elif "sqlite" in database_vendor:
         sql_analyser_class = SqliteAnalyser
     else:
-        sql_analyser_class = BaseAnalyser
+        raise ValueError("Unsupported database vendor. Try specifying an SQL analyser.")
 
     logger.debug("Chosen SQL analyser class: %s", sql_analyser_class)
-    return sql_analyser_class(exclude_migration_tests)
+    return sql_analyser_class
 
 
 def analyse_sql_statements(
-    sql_statements, database_vendor, exclude_migration_tests=None
+    sql_analyser_class, sql_statements, exclude_migration_tests=None
 ):
-    sql_analyser = get_sql_analyser(database_vendor, exclude_migration_tests)
+    sql_analyser = sql_analyser_class(exclude_migration_tests)
     sql_analyser.analyse(sql_statements)
     return sql_analyser.errors, sql_analyser.ignored, sql_analyser.warnings