[magnusp]

Closes #41. Part of #54.

What changed

• LibsqlDatabaseMetaData.getTables now builds the xerial-shaped union instead of selecting every sqlite_master row:
  • a sqlite_schema SYSTEM TABLE row,
  • user rows filtered to UPPER(TYPE) IN ('TABLE', 'VIEW'),
  • sqlite_temp_master rows as GLOBAL TEMPORARY,
  • sqlite_% rows as SYSTEM TABLE.
• The types argument is honored. null and an empty array add no filter; a non-empty array is uppercased and emitted as TABLE_TYPE IN (...).
• A null or empty table-name pattern maps to %, matching xerial. Single quotes are still escaped, and the pattern uses LIKE ... ESCAPE '\'.
• Tests cover null types, an empty array, {"TABLE"}, {"VIEW"}, mixed-case multiple types, an empty name pattern, and the existing quote-escape case.

Contract decision

Parity with xerial 3.53.4.0 JDBC3DatabaseMetaData.getTables (lines 1682-1750). The union, the TABLE/VIEW user-row filter, the system and temporary rows, the types filter behavior, the LIKE ... ESCAPE '\' pattern handling, and the ORDER BY TABLE_TYPE, TABLE_NAME ordering all match. No transport limitation required a different shape.

Evidence

Tests were added first and failed on the pre-fix code:

./mvnw -pl libsql-jdbc -am test -Dtest=LibsqlDatabaseMetaDataTest -Dsurefire.failIfNoSpecifiedTests=false
[ERROR] Tests run: 9, Failures: 7, Errors: 0, Skipped: 0

Representative failures: the pre-fix SQL had no sqlite_schema/SYSTEM TABLE branch, no sqlite_temp_master/GLOBAL TEMPORARY branch, no UPPER(TYPE) IN ('TABLE', 'VIEW') filter, no TABLE_TYPE IN (...) filter for {"TABLE"}/{"VIEW"}, and turned an empty pattern into LIKE ''.

After the fix:

./mvnw -pl libsql-jdbc -am test
Tests run: 154, Failures: 0, Errors: 0, Skipped: 0
BUILD SUCCESS

./mvnw -pl libsql-conformance -am verify
Tests run: 115, Failures: 0, Errors: 0, Skipped: 1
BUILD SUCCESS

The conformance run exercises real sqld and includes MetadataLeakTest, which calls getTables(null, null, null, null).

I also executed the generated union against a real SQLite engine (xerial 3.53.4.0) with a table, a view, an index, a trigger, and a temp table. Null types returned tmp (GLOBAL TEMPORARY), sqlite_schema (SYSTEM TABLE), t (TABLE), and v (VIEW); {"TABLE"} returned only t; the index and trigger never appeared.

./mvnw spotless:apply completed successfully before the final commit.

Deviations

none