Fix PostgresAdapter support for ARRAY and custom enum array columns

[JulienChavee]

Fix PostgresAdapter support for ARRAY columns

Summary

PostgresAdapter::getColumns() throws when introspecting PostgreSQL array columns:

Phinx\Db\Adapter\UnsupportedColumnTypeException: Column type `ARRAY` is not supported by Postgresql.

PostgreSQL's information_schema.columns reports array columns as data_type = 'ARRAY', with the element type in udt_name (e.g. _int4, _text, _bpchar). Phinx already supported creating array columns (integer[], text[], …) but could not read them back.

A related failure occurred for arrays of custom/user-defined types (e.g. enums):

Phinx\Db\Adapter\UnsupportedColumnTypeException: Column type `my_status_enum[]` is not supported by Postgresql.

isArrayType() previously required a known Phinx base type and only allowed [a-z]+, so identifiers with underscores were rejected.

Changes

• Resolve ARRAY columns in getColumns() via udt_name and pg_attribute.attndims
• Accept arrays of native/custom PostgreSQL types (enums, domains, etc.) in isArrayType / getSqlType
• Translate known Phinx array base types through getSqlType (string[] → character varying[]); pass custom types through unchanged
• Map common PostgreSQL internal aliases in getPhinxType used by array udt_name values:
  • int2 → smallinteger
  • float8 → double
  • bpchar → char
• Extract array handling into parseArrayType(), getArraySqlType(), and getPhinxArrayType()

Example

SELECT column_name, data_type, udt_name
FROM information_schema.columns
WHERE table_name = 'my_table' AND data_type = 'ARRAY';

column_name	data_type	udt_name
tags	ARRAY	_varchar
scores	ARRAY	_int4
statuses	ARRAY	_my_status_enum

After this change, getColumns() maps those to string[], integer[], and my_status_enum[] respectively.

Test plan

• getColumns() round-trip for Phinx-created array types (text[], integer[], multi-dimensional json[][], …)
• Native SQL array columns (varchar[], integer[][])
• Custom enum array columns (custom_status_enum[]), including changeColumn round-trip
• Internal udt_name aliases (_int2, _float8, _bpchar, …)
• getSqlType() translation of Phinx array base types (string[] → character varying[], etc.)
• Full PostgresAdapterTest suite