From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Mon, 30 Jan 2012 17:31:08 +0000 (-0500)
Subject: - add test coverage for standalone MigrationContext / Operations
X-Git-Tag: rel_0_2_0~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=68d380135c752e9bb1054ee0126269b9d64f6ebe;p=thirdparty%2Fsqlalchemy%2Falembic.git

- add test coverage for standalone MigrationContext / Operations
- ensure MigrationContext.configure can be used with a single connection
argument
---

diff --git a/alembic/migration.py b/alembic/migration.py
index 2e817e64..544942cd 100644
--- a/alembic/migration.py
+++ b/alembic/migration.py
@@ -28,6 +28,18 @@ class MigrationContext(object):
     
         from alembic import context
         migration_context = context.migration_context
+    
+    A :class:`.MigrationContext` can be created programmatically
+    for usage outside of the usual Alembic migrations flow,
+    using the :meth:`.MigrationContext.configure` method::
+    
+        conn = myengine.connect()
+        ctx = MigrationContext.configure(conn)
+    
+    The above context can then be used to produce
+    Alembic migration operations with an :class:`.Operations`
+    instance.
+    
 
     """
     def __init__(self, dialect, connection, opts):
@@ -69,7 +81,7 @@ class MigrationContext(object):
                 connection=None,
                 url=None,
                 dialect_name=None,
-                opts=None,
+                opts={},
     ):
         """Create a new :class:`.MigrationContext`.
         
diff --git a/tests/__init__.py b/tests/__init__.py
index bb06ae7f..e8baba87 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -35,6 +35,13 @@ def sqlite_db():
     dir_ = os.path.join(staging_directory, 'scripts')
     return create_engine('sqlite:///%s/foo.db' % dir_)
 
+def capture_db():
+    buf = []
+    def dump(sql, *multiparams, **params):
+        buf.append(str(sql.compile(dialect=engine.dialect)))
+    engine = create_engine("postgresql://", strategy="mock", executor=dump)
+    return engine, buf
+
 _engs = {}
 def db_for_dialect(name):
     if name in _engs:
diff --git a/tests/test_config.py b/tests/test_config.py
index fb54e8aa..f0bd1674 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -1,5 +1,7 @@
 from alembic import config
-from tests import eq_
+from alembic.migration import MigrationContext
+from alembic.operations import Operations
+from tests import eq_, capture_db
 
 def test_config_no_file_main_option():
     cfg = config.Config()
@@ -15,4 +17,14 @@ def test_config_no_file_section_option():
     eq_(cfg.get_section_option("foo", "url"), "postgresql://foo/bar")
 
     cfg.set_section_option("foo", "echo", "True")
-    eq_(cfg.get_section_option("foo", "echo"), "True")
\ No newline at end of file
+    eq_(cfg.get_section_option("foo", "echo"), "True")
+
+
+def test_standalone_op():
+    eng, buf = capture_db()
+
+    env = MigrationContext.configure(eng)
+    op = Operations(env)
+
+    op.alter_column("t", "c", nullable=True)
+    eq_(buf, ['ALTER TABLE t ALTER COLUMN c DROP NOT NULL'])