v7 Roadmap

[andrii-bodnar]

Lingui 6 was about distribution: ESM-only packages and a modern Node.js baseline. Lingui 7 is about the toolchain.

Over the 6.x cycle we shipped a Rust and SWC based toolchain, @lingui/native-tools, behind opt-in flags: the native macro transform in @lingui/vite-plugin (macroTransform: true), the native extractor (createSwcExtractor()), and native bundling in lingui extract-experimental. It is up to 2.5x faster than SWC with the Lingui plugin and up to 29x faster than Babel, and it has been dogfooded on real projects since the lingui-swc preview (#2436).

Babel still sits underneath everything by default. @lingui/cli pulls in @babel/core, @babel/parser, @babel/generator and both Lingui Babel plugins as hard dependencies, even for projects that use only the native paths (#2699). The CLI is also pinned to Babel 7, so Babel 8 projects end up with two Babel majors installed (#2644), and we deferred that move to the next major because it has Node engine and parser implications.

V7 flips the defaults: the native transform and the native extractor become the default, lingui compile stops depending on Babel, and the Babel packages become optional peer dependencies. The Babel extractor and the Babel macro plugin stay fully supported for projects that need them (Flow, Babel-only syntax, custom Babel pipelines, Vue), you just install Babel explicitly. At the same time we move the CLI to Babel 8 and remove the deprecations accumulated over 5.x and 6.x.

As with v6, the headline change is big enough on its own. Everything else in this list is either a deprecation removal or a small cleanup that needs a major anyway.

Testing checklist:

• Ensure the native defaults work with webpack (@lingui/loader), Metro and Next.js setups
• Ensure Solid and Vue projects still work, Solid through the native transform, Vue through the Babel extractor
• Ensure the Babel extractor and @lingui/babel-plugin-lingui-macro work on Babel 7 and Babel 8
• Test on real projects before the first RC

Reconsider the minimum Node.js version. v6 set 22.19+. Node.js 22 reaches end of life in April 2027, so depending on the release date v7 may start at 24+.

Blockers:

• useLingui transform emits $__i18n._() which crashes with @lingui/solid swc-plugin#275
• Support macro.jsxRuntime: "solid" for the <Trans> transform swc-plugin#276
• createSwcExtractor ignores the macro option it accepts (lingui/swc-plugin, to be filed)
• refactor(babel-plugin-lingui-macro): use types from the Babel plugin API #2698

Native toolchain by default

• @lingui/vite-plugin: macroTransform defaults to true; linguiTransformerBabelPreset stays as the opt-out path and stops printing the notice
• @lingui/cli: createSwcExtractor() becomes the default extractor, Babel extractor becomes opt-in via extractors: [createBabelExtractor()]
• @lingui/cli: rewrite compile catalog module generation without @babel/generator and @babel/types, remove compilerBabelOptions
• @lingui/cli: lazy-load the Babel extractor, move @babel/* and the Lingui Babel plugins to optional peer dependencies Can Babel dependencies be optional when using the native Vite transform and experimental extractor? #2699
• Drop the Solid guard in @lingui/vite-plugin once @lingui/native-tools ships Solid support vite-plugin: macroTransform generates invalid code for SolidJS #2705
• @lingui/native-tools: remove the temporary useLinguiV5IdGeneration option, make useJsdocI18nComment the default
• Decide the fate of extract-experimental: promote dependency-tree crawling to a lingui extract mode, or keep it as is

Babel 8

• Move @lingui/cli and the remaining packages to Babel 8, carrying over the CLI-side changes from feat(cli): move the extractor toolchain to Babel 8 #2644
• Keep ^7 || ^8 peer ranges in @lingui/babel-plugin-lingui-macro and @lingui/babel-plugin-extract-messages

Remove deprecations:

• Using Lingui macros via babel-plugin-macros (deprecated since v6), drop the babel-plugin-macros peer dependency from @lingui/core and @lingui/react
• extractorParserOptions config option, use createBabelExtractor({ parserOptions }) instead
• experimental.extractor legacy options includeDeps, excludeExtensions, resolveEsbuildOptions, use bundler: createEsbuildBundler({ ... })
• pseudoLocale string form, use the object form { locale: "pseudo" }
• i18n.date(), i18n.number() and the formats helpers in @lingui/core, use Intl.DateTimeFormat and Intl.NumberFormat directly
• extractor export from @lingui/extractor-vue, use createVueExtractor()

To discuss (not blockers)

• Revisit lingui check defaults: which checks run by default and at which severity
• Naming of macro vs runtime components Consider renaming of the macro components #1908

Documentation

• v7 migration guide
• Release blog post
• Update installation docs so the native setup is the only default path, Babel and SWC setups move to an "advanced" section

Post-release

• Close Rust extractor #2436 and Can Babel dependencies be optional when using the native Vite transform and experimental extractor? #2699 tracking issues
• Update the lingui/skills references for the new defaults
• Set up a Babel 8 example project

[timofei-iatsenko]

What about moving babel extractor in a separate package in v7 with direct babel depenedencies, and left cli entirely babel-free. This will give an another benefit - it would be possible to looks for a stats how many people still using a babel implementation.

[andrii-bodnar]

Agreed, a separate package is cleaner than optional peers. I’ll update the checklist.

[MurzNN]

What about renaming i18n._ to i18n.t finally? With keeping _ as an alias to t for backward compatibility. Here is a discussion about this: #2470

Also, take into account that using the i18n._ should be more popular with the new feature "runtime macro" 😉 but recommending using the underscore function name looks confusing.

[andrii-bodnar]

As I remember, there were some changes related to this at the documentation level with the v6 release

[macocha]

When it comes to @lingui/vite-plugin it'd be nice if it could be run to perform just the transform, so we could do something like:

    plugins: [
      lingui({ transformOnly: true }),
      react({ compiler: true }),
      lingui(),
    ]

This react-compiler wrapping is the only reason to pull in babel for me.