Feature request: expand the usage of hooks (JSR-223 and SQL) to all migration commands

[sjanssens1977]

In my search for a solution to manage test data using MyBatis Migrations I stumbled upon the hooks feature.

I managed to implement a solution by which I use the [before|after]each[up|down] hooks to temporary replace a script which contains test data insert statements with an script containing no sql statements.
This implementation works great if you use the up and down commands to manage each environment.

Because of certain regulations the production environment needs to be maintained using plain old sql files.
Unfortunately the hooks feature only works for the commands up and down.
This means, in my case, that a script, generated by the script command on the same set of migration scripts for the same environment, after execution, will result in a different database compared to using the up command.

Therefore I would like to ask if the hooks feature could also be expanded to the other commands: script, version, pending.

The solution is simple and just needs 3 files (do not forget to change the file extension to .sql and .js)
empty_migration_script.txt
post-process.txt
pre-process.txt

Regards,
Steven Janssens.

[harawata]

Hi @sjanssens1977 ,

I'm sorry for a late reply!

version and pending are special cases of up/down, so it makes sense to apply hooks when executing these commands.
I will look into it.

Regarding script command, though, applying hook seems inappropriate.
Executing SQL hook on every execution of script command may not be what users expect, for example.

In your case, the recommended solution would be to store the environment-dependent DML scripts (i.e. test data insert statements) in a separate directory than DDL scripts.
Here is an example directory structure.

BASE_DIR
├── drivers
├── environments
├── hooks
├── scripts
│   ├── 001_create_changelog.sql
│   ├── 002_first_migration.sql
│   └── 003_second_migration.sql
└── testdata
    ├── 002.sql
    └── 003.sql

The idea is to insert test data using hook in non-production environment.
In the example above, 002.sql will be executed after 002_first_migration.sql is applied.
The after-each-up script would look something like this (not tested).

var Files = Java.type("java.nio.file.Files");
var Paths = Java.type("java.nio.file.Paths");
var String = Java.type("java.lang.String");
var StandardCharsets = Java.type("java.nio.charset.StandardCharsets");

var path = Paths.get(migrationPaths.getBasePath()
  + "/testdata/" + hookContext.getChange().getId() + ".sql");
if (Files.exists(path)) {
  var query = String.join("\n",
    Files.readAllLines(path, StandardCharsets.UTF_8));
  hookContext.executeSql(query);
}

script command does nothing special.

The above script is taken from this Japanese blog entry written by a user who had a similar requirement as yours.

[harawata]

Hooks are now applied to 'version' and 'pending' (#81).