Instructions for setting up `vue-test` when migrating from Vue 2 to Vue 3? about vue-jest

[estberg]

I see some time has passed since your question, but documenting this here in case it helps anyone.

Single file components seem to be transformed assuming Vue3 without vue/compat when just installing @vue/vue3-jest without no additional configuration.

However, it turns out that compilerOptions for 'vue-jest' can be configured, similar to what might be set up in the 'vue/compat' installation build step (see step 3).

For example, adding the following in jest.config.js seems to configure the compilation options for vue-jest to match the vue/compat MODE: 2 configuration:

  globals: {
    'vue-jest': {
      compilerOptions: {
        compatConfig: {
          MODE: 2
        },
      }
    }
  }

This can also nicely integrate with vue-test-utils-compat if you are working on migrating and focusing on jest tests.