Investigate warning

[przemyslaw-zan]

Reproduction steps:

1. Use same assertions as in this test at this commit
2. Run yarn run coverage --browsers=Chrome,Firefox

Expected behaviour:

The test passes

Actual behaviour:

Test assertion finds an unexpected warning in the browser:

Feature flag VUE_PROD_HYDRATION_MISMATCH_DETAILS is not explicitly defined. You are running the esm-bundler build of Vue, which expects these compile-time feature flags to be globally injected via the bundler config in order to get better tree-shaking in the production bundle.

For more details, see https://link.vuejs.org/feature-flags.