fix: select contexts by contextIds regardless of fullyQualifiedTableNames

[mvanhorn]

Summary

Fixes #1547: when a caller supplies contextIds but no fullyQualifiedTableNames, MyBatis Generator ignores the contextIds and runs every context instead of the requested subset. This restores the pre-2.0 selection behavior. The regression was confirmed by @jeffgbutler in the issue thread.

Background

MyBatisGenerator.calculateContextsToRun() decides whether to run all configured contexts or only the subset named in contextIds. In 2.0 it branches on whether fullyQualifiedTableNames is empty:

if (fullyQualifiedTableNames.isEmpty()) {
    contextsToRun = configuration.getContexts();          // run everything
} else {
    contextsToRun = configuration.getContexts().stream()
            .filter(c -> contextIds.contains(c.getId()))
            .toList();
}

Context selection and table-name filtering are independent concerns — the table names are applied later, during introspection in runContextIntrospection. Tying context selection to the table-name set means that calling generate(callback, contextIds, Collections.emptySet()) runs every context, ignoring contextIds. In 1.4.2 and earlier the subset selection worked as expected.

Fix

Branch on contextIds.isEmpty() instead:

if (contextIds.isEmpty()) {
    contextsToRun = configuration.getContexts();
} else {
    contextsToRun = configuration.getContexts().stream()
            .filter(c -> contextIds.contains(c.getId()))
            .toList();
}

contextIds is a final, non-null HashSet, so no null guard is needed. The "run all contexts" branch is now taken only when no contextIds are specified, regardless of whether table names are also supplied.

Testing

Added a database-free unit test that invokes the private calculateContextsToRun() via reflection (validation runs inside generate(), so a MyBatisGenerator built with minimal contexts needs no live database) and covers three cases:

• contextIds supplied, no table names → only the requested context runs (the reported regression);
• no contextIds → all contexts run;
• contextIds supplied together with a table name → still only the requested context.

MyBatisGeneratorTest passes with the fix; the new test fails against the unpatched code (it runs both contexts), confirming it catches the regression.

Closes #1547

AI was used for assistance.

[jeffgbutler]

Please don't use reflection for testing. Make the method under test have package private visibility, then tests in the same package can see it.

[mvanhorn]

Done in f1671a4. The method is package private now and the test moved into org.mybatis.generator.api so it calls it directly, no reflection. Core suite still passes (1289 tests).

[coveralls]

coverage: 92.535%. remained the same — mvanhorn:fix/contextids-empty-tablenames into mybatis:master

[jeffgbutler]

Thanks!

[mvanhorn]

Thanks for getting this in. Appreciate you taking the contextIds selection fix so callers do not have to pass table names too.