Support bracketed IPv6 hosts in connection strings

[Nitjsefnie]

Summary

Connection strings with a bracketed IPv6 host (postgres://u:p@[::1]:5432/db) resolved to host [ and could not connect; each host entry is now parsed with bracket awareness, and a bare IPv6 host option or PGHOST value is kept whole.

Related Issues and Pull Requests

Fixes #1232

Relates to #663

Relates to #1127

Changes

• src/index.js: parseOptions maps each comma-separated host entry through a small parseHost helper. [addr] / [addr]:port yields addr and that port (or the default), an unbracketed value with more than one : (a bare IPv6 address such as ::1) is taken whole, and everything else is split at : exactly as before, so hostname, IPv4, host:port, multi-host and socket-path behaviour is unchanged.
• tests/index.js: five cases next to Multiple hosts — bracketed IPv6 with and without a port, two bracketed hosts, a bare ::1 host option, and the existing h1:1,h2:2 form.
• cjs/, deno/, cf/: the matching npm run build output for those two files only.
• Compared with the open pull requests: add support for ipv6 addr postgres://user:password@[2a02:c206:2140:4… #663 fixes the bracketed URL case but throws ERR_INVALID_URL for a bare ::1 host option and has no tests; refactor: Use new URL for connection string parsing #1127 turns a multi-host entry [::1]:5432 into host ::1]:543.

Testing

• The new tests failed on master ('[["::1"],[5432]]' != '[["["],[5432]]') and pass with the change.
• Full node tests/index.js and node cjs/tests/index.js passed against a local PostgreSQL with the second server on port 5433, as in CI. Two existing timing-sensitive tests (reserve connection, listen and notify with weird name) failed on earlier runs and passed on re-run; they do not touch host parsing.
• npm run lint passed.
• The Deno tests were not run (no Deno CLI available); the Deno files are the build output.
• The same change has run as a local patch on 3.4.9 in Nitjsefnie/Overflow, whose suite includes a test that connects to a server listening only on ::1.

Footer

Generated by Claude Opus 5.5 (brief, review), GPT-6 Sol (implementation, review)