formatjs extract typescript error on message id

Fix formatjs extract failing on TypeScript message ids

TL;DR

The extractor is running without TypeScript support, so add the TS preset to the babel config it uses. Formatjs extract shells out to babel, and plain babel chokes on types, enums, and satisfies expressions. Once the TS plugin is in the chain, extraction sees the messages again.

The error

Error: Support for the experimental syntax 'typescript' isn't currently enabled
while running: formatjs extract 'src/**/*.ts'

Fix it

Step 1: Check what babel config the extractor picks up

ls babel.config.js .babelrc; grep -rn "preset-typescript" babel.config.js

Expected: You see whether the TS preset is present or missing.

Step 2: Add the TypeScript preset

node -e "console.log('in babel.config.js presets add: [\"@babel/preset-typescript\", {\"isTSX\": true, \"allExtensions\": true}]')"

Expected: The config now includes preset-typescript.

Step 3: Re-run extraction on the TS sources

npx formatjs extract 'src/**/*.ts*' --out-file /tmp/messages.json | tail -3

Expected: Extraction completes and the output file has your messages.

Step 4: Confirm message count looks right

node -e "const m=require('/tmp/messages.json'); console.log(Object.keys(m).length,'messages extracted')"

Expected: The count matches roughly what you expect from the codebase.

When to use this

• formatjs extract fails with a TypeScript syntax error
• You extract from .ts or .tsx files

When NOT to use this

• Extraction runs but finds zero messages, check the glob and the defineMessages usage
• The failure is on a .js file, that is a different parser issue

Tool and version compatibility

• @formatjs/cli v5/v6, @babel/preset-typescript
• Babel 7 with a babel.config.js at the repo root

Variant phrasings

extract fails on TS enums in message files

Same fix. The TS preset handles enums, the default parser does not.

works locally but fails in CI

CI probably runs extract from a different cwd so babel finds no config. Pass --config or run from the repo root.

Why it happens

Formatjs extract parses sources with babel using your project babel config. Without preset-typescript, babel treats .ts files as plain JS and dies on the first type annotation. The extractor never gets to the defineMessages calls.

Edge cases

• isTSX and allExtensions matter, without them .ts files may still fail
• A .babelrc in a subfolder can shadow the root config for those files
• Decorators need their own plugin too if message files use them

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_ujNWV1oCgPhjNBrZLArt0Q