New Action to transform entries to another content type

[aKzenT]

Summary

This PR extends the available migrations with a new "transformEntriesToType"-transform that allows migrations from one content type to another as discussed in #113

Description

A new action was added to support the transformation. Various enhancements to the OfflineAPI as well as the Fetcher were needed to implement the features.

Motivation and Context

See #113

Todos

• Basic functionality working
• Option to remove the source item after transformation
• Option to publish/not publish or keep the state of the original entry
• Option to change all references to the original entry so that they point to the new entry instead
• Additional tests

[aKzenT]

@TimBeyer can you take a look at the changes? We are planning to do several more migrations in the beginning of January, which will further test this new migration type.

[Khaledgarbaya]

Hey @aKzenT,

This is ready to merge. can you please run npm run lint and fix the linting issues and push again.

After that, I will merge this PR.

[GordonApplepie]

happy new year all together. @Khaledgarbaya I fixed the linter errors as requested. I am a bit unsure of the warning "no-unused-variable is deprecated" since this is a linter settings issue. I would ignore this for now?

[TimBeyer]

@GordonApplepie you can ignore it for now.
I think this is now a Typescript setting and so the linter option has been deprecated.

[phoebeschmidt]

🎉 This PR is included in version 0.16.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[GordonApplepie]

🎉🎉🎉 @aKzenT

thanks to all

[Khaledgarbaya]

Hey @aKzenT and @GordonApplepie we would like to send you some thank you swags for your contributions.
Can you ping me at this email khaled[at]contentful.com with your addresses so we can ship them to you?

[TimBeyer]

Hey @aKzenT, I just realized that we forgot to add a README.md addition for this change.
Do you think you could still open a small PR for that so that this is documented for everyone? 🙂

[GordonApplepie]

Hi @TimBeyer, I will look after that now. Sadly I found a problem due to recent updates in the master branch regarding the "fetcher.ts". There is a new filter implementation that actually prevents to load the complete list of entries which we need to update the references.

I will describe it again in the pull request. Editing the readme file now.

[jarkkosyrjala]

I'm getting "Validation failed" error when trying to use shouldPublish: 'preserve':

"string" is not a valid type for the content transformation property "shouldPublish". Expected "boolean".

Using version 0.16.3

Full example of the migration file:

module.exports = function (migration) {
  const fields = ['field1','field2','field3']
  const contentType = 'exampleContentType'
  const sourceLocale = 'en'
  const targetLocale = 'en-US'
  migration.transformEntries({
    contentType: contentType,
    from: fields,
    to: fields,
    shouldPublish: 'preserve',
    transformEntryForLocale: function (fromFields, currentLocale) {
      if (currentLocale === targetLocale) {
        return fields.reduce(function(result, fieldName) {
          if (fromFields[fieldName] && fromFields[fieldName][sourceLocale]) {
            result[fieldName] = fromFields[fieldName][sourceLocale]
          }
          return result;
        }, {});
      } else {
        // Ignore other locales
        return;
      }
    }
  });
};

Should I create a separate Issue about this?

[GordonApplepie]

@jarkkosyrjala I think you are mixing two different actions here "transformEntries" is not "transformEntriesToType". "preserve" is only available in the last one.

[TimBeyer]

@GordonApplepie if I saw it correctly, then 'preserve' was also implemented for the normal transformEntries in this PR. Probably it just wasn't added to the validations.

[TimBeyer]

@GordonApplepie what I updated in the fetcher was to always iterate through all pages for all paginated types, and to exclude archived entries from the transform.
Which one of those is causing you trouble?

Our assumption was that since archived entries are basically soft deleted, they most likely should not be part of any transform or derive action.

[GordonApplepie]

#163

[TimBeyer]

@GordonApplepie I made a PR that fixes the issue in #164

[jarkkosyrjala]

@GordonApplepie if I saw it correctly, then 'preserve' was also implemented for the normal transformEntries in this PR. Probably it just wasn't added to the validations.

Made a PR that fixes this: #165