✨ Ranking of aggregated search results based on relevancy of the search result to the user's search query

[spencerjibz]

What does this PR do?

Implements an algorithm to rank (in other words, sort) the aggregated search results according to the relevancy of the search result based on the user's search query by analyzing three properties of the search results:

• The search result's tile
• description
• and URL.

Also, check each of the properties for how closely they are related if they are too closely related then it should be the first result in all search results. If it is the least related, then it should be the last result to be shown in all the search results.

Chosen Ranking function: TF-IDF (Term Frequency-Inverse Document Frequency)
This is a weighting scheme often used by search engines as a central tool in scoring and ranking a document's relevance given a user query, find implementation details below:

• Our implementation measures the relevance of a user's query in a collection of corpus (title, description and URL), then finally sorts the results by the relevance score.
• Optional: we can also opt-in to weigh the query by synonyms found in the search title, description and URL. This feature can be enabled using the flag use-synonyms-search or use-non-static-synonyms-search.

Caution

This feature flag enables using an offline thesaurus library (moby) to find synonyms and add them to the relevance calculations), there is both a performance and binary size cost when this feature is used..

For more information on this ranking function, check out this article

Why is this change important?

Currently, the Search engine doesn't sort results by importance or relevance. This PR aims to solve that.

How to test this PR locally?

It can be tested by installing and running Websurfx as mentioned in the docs and on the readme and by launching the browser and thoroughly testing. On searching for a topic, you find that the most relevant results are returned first .

To try out using synonyms, build or run Websurfx with the feature flag use-synonyms-search

Related issues

Closes #393

[ddotthomas]

LGTM, the search is much more accurate now too.

[neon-mmd]

Sorry for the late review.

Thanks ❤️ for working on this PR. We really appreciate it 👍 Keep it up!! But before we merge this PR. We would like to suggest a few changes. 🙂.

[neon-mmd]

Thanks ❤️ again for working on this. Now since everything looks good. We will merge the PR as soon as possible. 🙂

[alamin655]

Approved! Let's merge this in. 👍