test: Lang field read only

[M123-dev]

What

Related to: openfoodfacts/smooth-app#4771 (comment)

Start lang: OpenFoodFactsLanguage.FRENCH

End lang: OpenFoodFactsLanguage.FRENCH

00:18 +0 -1: OpenFoodAPIClient Save product main language Save product main language [E]

  Expected: OpenFoodFactsLanguage:<OpenFoodFactsLanguage.GERMAN>
    Actual: OpenFoodFactsLanguage:<OpenFoodFactsLanguage.FRENCH>

00:18 +0 -1: Some tests failed.

It looks like we have a good old read only field

[monsieurtanuki]

@M123-dev Thank you for your test!

That said:

• it's MUCH better if you save data and get data from the same server, consistency-wise

      ProductResultV3 result = await OpenFoodAPIClient.getProductV3(
        ProductQueryConfiguration(
          barcode_1,
          version: ProductQueryVersion.v3,
        ),
        uriHelper: uriHelper, // was missing in your code
      );

• it's also a good practice to check return codes, e.g. for the saveProduct call
• that said, you're right!
• And wrong. For "your" barcode (3017620425035) and the first barcode I tried (3350031897306) the language didn't change and cause a test failure. But for another one (8027498025058) the test passed.

@stephanegigandet I already experienced some madness tests with fields that couldn't be changed for some products. I guess some fields are locked on some products, like "the producer says this is the right value and it's irrelevant to change it". Is there a way we can detect which fields are locked for which products?