Escaping differs between `dev` and `build`

[manuel-mauky]

Description

I want to show { and } characters in a message so I'm escaping them with ' as described in the docs.

For example, take this message string from the docs: "Escape curly braces with single quotes (e.g. '{name'})"

When starting the app with npm run dev, it works as expected and shows {name}.
However, when running npm run build and npm run start, it's including the escape characters: '{name'}.

We noticed this bug when updating to 4.3.1 in our app. Before we were using 3.9.0 and everything worked fine.

Verifications

• I've verified that the problem I'm experiencing isn't covered in the docs.
• I've searched for similar, existing issues on GitHub and Stack Overflow.
• I've compared my app to a working example to look for differences.

Mandatory reproduction URL

https://stackblitz.com/edit/stackblitz-starters-qrums7tb

Reproduction description

Steps to reproduce:

1. Open reproduction
2. Start the app with npm run dev to see the correct behavior
3. Start the app with npm run build & npm run start to see the wrong behavior

Expected behaviour

In the prod build the escape characters (') shouldn't be visible.
There should be no difference between dev server and prod build.

[manuel-mauky]

I think the reason is in createBaseTranslator.tsx -> getPlainMessage:
https://github.com/amannn/next-intl/blob/405beefbae0fc1973a6870dd9399a1eac42ff28a/packages/use-intl/src/core/createBaseTranslator.tsx#L152C1-L169C2

There is a check for process.env.NODE_ENV !== "production" and the escaping is only done when not in production mode.

In useTranslations.test.tsx there is already a test for escaping. This test case can be adjusted like this to reproduce the issue:

it('can escape curly brackets in production mode', () => {
  vi.stubEnv('NODE_ENV', 'production');
  renderMessage("Hello '{name'}");
  screen.getByText('Hello {name}');
})

[amannn]

Hey, thank you for the careful bug report! There is indeed a wrong assumption here in the code, looking into this now.