Add functionality to recognize German adjective forms

manuelaugustin commented 5 years ago

Summary

This PR can be summarized in the following changelog entry:

[not-user-facing] Adds functionality to create German adjective forms.

Relevant technical choices:

For nouns, we check exceptions by matching the exception stems at the end of the stemmed word. This is because nouns are commonly are used in compounds (e.g. stadt in Hauptstadt). Since this is far less common for adjectives, I decided to match exceptions with the full stemmed word.
I added some function words we came across while researching adjectives.

Test instructions

This PR can be tested by following these steps:

Make sure you have the premium configuration set to the right branch (see https://github.com/Yoast/YoastSEO.js-premium-configuration/pull/7).
Change the language of your site to German.
Add a German text and a keyphrase including German adjectives.
Add different grammatical forms of the adjective in your text; make sure these forms are recognized.

Fixes #2127

manuelaugustin commented 5 years ago

Good point about the function names/documentation! I've changed the naming as suggested.

igorschoester commented 5 years ago

Standalone works 👍 In combination with the plugin, the worker.initialize executing in the console didn't work for some reason. Since there will be a better way to test this in the future and this did work in the standalone I don't think this is a blocker at this point.

Acceptance 👍

Yoast / YoastSEO.js