The Data Charmer: MySQL Test Creator - wrapping up a Summer of Code experience

I talked about this matter already, but now it's time to wrap up.
The Summer of code is over, and the project I have mentored is finished, with a new tool as its outcome, the MySQL test creator.

The student who developed this tool, Charlie Cahoon, did a decent job. All in all, considering that it was his first serious developing experience, he got an excellent result. The maturity stage is still alpha, but he did the breakthrough work to get the development of this tool in the right track.

What do we have in hour hands? A tool that will speed up and make easy the writing of test scripts, during a normal session with the MySQL client. It means that you will fiddle with the database in your usual way, and the test creator will work in the background, writing a test script with its corresponding result file.
Its features include

starting, stopping and resetting the background script creation;
using loops;
removing errors from the script;
undoing the last command;
showing the test script.

Let's see an example.


mysql> start;
+------------------------+
| TEST CREATOR           |
+------------------------+
| Testing has started... |
+------------------------+
1 row in set (0.00 sec)

mysql> create table t1 (id int);
Query OK, 0 rows affected (0.01 sec)

mysql> set @counter = 0;
Query OK, 0 rows affected (0.00 sec)

mysql> start_loop myvar 100;
+-------------------------+
| TEST CREATOR            |
+-------------------------+
| Beginning loop creation |
+-------------------------+
1 row in set (0.00 sec)

mysql> set @counter = @counter + 1;
Query OK, 0 rows affected (0.00 sec)

mysql> insert into t1 values (@counter);
Query OK, 1 row affected (0.00 sec)

mysql> stop_loop;
+--------------------------------+
| TEST CREATOR                   |
+--------------------------------+
| Executed 2 queries X 100 times |
+--------------------------------+
1 row in set (0.02 sec)

mysql> select count(*) from t1;
+----------+
| count(*) |
+----------+
|      100 |
+----------+
1 row in set (0.00 sec)

mysql> stop;
+---------------------+
| TEST CREATOR        |
+---------------------+
| Testing has stopped |
+---------------------+
1 row in set (0.00 sec)

mysql> view test;
+-----------------------------------+
| Test File                         |
+-----------------------------------+
| --disable_warnings                |
| DROP TABLE if exists t1;          |
| --enable_warnings                 |
| create table t1 (id int);         |
| set @counter = 0;                 |
| let $myvar = 100;                 |
| while ($myvar)                    |
| {                                 |
| set @counter = @counter + 1;      |
| insert into t1 values (@counter); |
| dec $myvar;                       |
| }                                 |
| select count(*) from t1;          |
+-----------------------------------+
13 rows in set (0.00 sec)

If you have ever tried to create a loop in mysqltest language, you know what a time saver this tool will be.
Another example. Getting rid of errors:


mysql> start;
+------------------------+
| TEST CREATOR           |
+------------------------+
| Testing has started... |
+------------------------+
1 row in set (0.00 sec)

mysql> select 1 as info;
+------+
| info |
+------+
|    1 |
+------+
1 row in set (0.00 sec)

mysql> select 2 as info;
+------+
| info |
+------+
|    2 |
+------+
1 row in set (0.00 sec)

mysql> select this is wrong;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'wrong' at line 1
mysql> view test;
+-----------------------+
| Test File             |
+-----------------------+
| connection con55;     |
| select 1 as info;     |
| select 2 as info;     |
| --error 1064          |
| select this is wrong; |
+-----------------------+
5 rows in set (0.00 sec)

mysql> discard_last;
+-------------------------------+
| TEST CREATOR                  |
+-------------------------------+
| Last query has been discarded |
+-------------------------------+
1 row in set (0.00 sec)

mysql> view test;
+-------------------+
| Test File         |
+-------------------+
| connection con55; |
| select 1 as info; |
| select 2 as info; |
+-------------------+
3 rows in set (0.00 sec)

mysql> select 3 as info;
+------+
| info |
+------+
|    3 |
+------+
1 row in set (0.00 sec)

mysql> wrong;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'wrong' at line 1
mysql> discard_last;
+-------------------------------+
| TEST CREATOR                  |
+-------------------------------+
| Last query has been discarded |
+-------------------------------+
1 row in set (0.00 sec)

mysql> view test;
+-------------------+
| Test File         |
+-------------------+
| connection con55; |
| select 1 as info; |
| select 2 as info; |
| select 3 as info; |
+-------------------+
4 rows in set (0.00 sec)

mysql> stop;
+---------------------+
| TEST CREATOR        |
+---------------------+
| Testing has stopped |
+---------------------+
1 row in set (0.00 sec)