[timofei-iatsenko]

Description

Currently, plural/select/selectOrdinal macros are inlined into the ICU message string when nested inside t or msg. But t and msg tagged template macros are NOT inlined when nested — they produce separate i18n._() calls and become opaque positional placeholders ({0}). This PR making t and msg tagged templates also inline their message content when nested.

Before (current): t`Field ${t`First Name`} is required` → two separate i18n._() calls, outer message is "Field {0} is required"

After (desired): t`Field ${t`First Name`} is required` → single call, message is "Field First Name is required"

This is basically needed for #2618 where option values cannot be template literals:

Template literals inside plural/select options (e.g., She is ${gender}) are already evaluated by the time they reach the function. However, the full functionality is preserved — instead of a plain template literal, users wrap it with t to produce a macro marker: t`She is ${{gender}}` instead of She is ${gender}. Nested macro markers (plural, select, selectOrdinal) work as option values as well.

Example of pattern which is supported now by compile time macro (note the nested msg in the option):

plural({ count }, { 0: msg`No books {{placeholder}}`, 1: msg`One book`, other: "# books" })}

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Examples update

Fixes # (issue)

Checklist

• I have read the CONTRIBUTING and CODE_OF_CONDUCT docs
• I have added tests that prove my fix is effective or that my feature works
• I have added the necessary documentation (if appropriate)

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Project	Deployment	Actions	Updated (UTC)
js-lingui	Ready	Preview	Jul 24, 2026 9:16am

[github-actions]

size-limit report 📦

Path	Size
packages/core/dist/index.mjs	1.69 KB (0%)
packages/detect-locale/dist/index.mjs	633 B (0%)
packages/react/dist/index.mjs	1.9 KB (0%)

[pkasarda]

Thank you for fixing "old" issue #1848 ❤️