localeCode schema lowercases the ?locale= filter, returning zero rows for locales with uppercase subtags

[khoinguyenpham04]

This Roadmap discussion mirrors #1551: localeCode schema lowercases the ?locale= filter, returning zero rows for locales with uppercase subtags.

Use this discussion to upvote the roadmap item and discuss priority, use cases, and product feedback. Keep implementation tracking, reproduction details, and PR-specific feedback on the source issue.

• Source issue: #1551
• Status: Open
• Labels: bug, bot:working, bot:bug
• Original author: ching-kuo

Original Issue

Description

Filtering content by a locale that has an uppercase subtag (like zh-TW or en-US) returns nothing on SQLite/D1, even though the rows exist.

My site's default locale is zh-TW. The admin content list came up completely blank, while the public site rendered all the posts fine. The API was returning {"items":[],"total":0} but the DB clearly had the data.

Tracked it down to localeCode in packages/core/src/api/schemas/common.ts:

export const localeCode = z
    .string()
    .regex(/^[a-z]{2,3}(-[a-z0-9]{2,8})*$/i, "Invalid locale code")
    .transform((v) => v.toLowerCase());

That .toLowerCase() rewrites ?locale=zh-TW to zh-tw before the query runs. But stored locales keep the configured casing — the column DEFAULT comes straight from defaultLocale (database/migrations/040_byline_i18n.ts:121) and the read fallback uses it raw (query.ts:513), so rows are stored as zh-TW. SQLite and D1 compare strings case-sensitively, so WHERE locale = 'zh-tw' matches zero rows. The public site dodges this because it never goes through the query-param schema.

So the filter lowercases but storage doesn't — the two sides disagree on casing. Affects any locale with an uppercase subtag (zh-TW, zh-Hant, en-US, pt-BR, fr-CA, ...).

Steps to reproduce

1. Set up i18n with an uppercase subtag, e.g. defaultLocale: "zh-TW".
2. Create or import some content (stored as locale = 'zh-TW').
3. Run on SQLite (or D1).
4. GET /_emdash/api/content/<collection>?locale=zh-TW → {"items":[],"total":0}.
5. Meanwhile SELECT count(*) FROM ... WHERE locale = 'zh-TW' returns the real count, and the admin content list shows up blank.

Environment

• emdash version: 0.21.0 (source unchanged on main, HEAD cb1c689)
• Node.js version: 22
• Runtime: Node
• OS: Linux (container)

Logs / error output