This change uses Module.redefine_method as defined in ActiveSupport.
Making Module.define_method public would be as clean in the code, and
would also emit warnings when redefining an association. That is pretty
messy given current tests, so I'm leaving it for someone else to decide
what approach is better.
Instead of generating association methods directly in the model
class, they are generated in an anonymous module which
is then included in the model class. There is one such module
for each association. The only subtlety is that the
generated_attributes_methods module (from ActiveModel) must
be forced to be included before association methods are created
so that attribute methods will not shadow association methods.
A recent change made to create_table does away with the
need for the block argument. Checking the arity will prevent the
mixing up of the two syntaxes.
The output in Travis is a bit different. The SQLite
documentation (http://www.sqlite.org/eqp.html) warns
output may change dramatically between releases. I
do not want to mock the result set because I want a
real EXPLAIN to happen. I prefer a test that may fail
in future releases than a test that may give false
positives in future releases.
This is a first implementation, EXPLAIN is highly
dependent on the database and I have made some
compromises.
On one hand, the method allows you to run the most
common EXPLAIN and that's it. If you want EXPLAIN
ANALYZE in PostgreSQL you need to do it by hand.
On the other hand, I've tried to construct a string
as close as possible to the ones built by the
respective shells. The rationale is that IMO the
user should feel at home with the output and
recognize it at first sight. Per database.
I don't know whether this implementation is going
to work well. Let's see whether people like it.
Reasons:
* Markdown reads well as plain text, but can also be formatted.
* It will make it easier for people to read on the web as Github
formats the Markdown nicely.
* It will encourage a level of consistency when people are writing
CHANGELOG entries.
The script used to perform the conversion is at
https://gist.github.com/1339263
Building the conditions of a nested through association could
potentially modify the conditions of the through and/or source
association.
This is a Bad Thing.
If a record is removed from a has_many :through, all of the join records
relating to that record should also be removed from the through
association's target.
(Previously the records were removed in the database, but only one was
removed from the in-memory target array.)
This change reduces churn in the db/development_structure.sql file when using :sql as
active_record.schema_format, and makes comparing diffs much easier.
Test ensures the output SQL-statements are lexically ordered by version.
