Autosuggest

Generate autocomplete suggestions based on what your users search

:tangerine: Battle-tested at Instacart

Installation

Add this line to your application’s Gemfile:

gem 'autosuggest'

How It Works

Start with the most popular queries

top_queries = Search.group("LOWER(query)")
                    .having("COUNT(DISTINCT user_id) >= 5")
                    .count("DISTINCT user_id")
# {"bananas" => 353, "apples" => 213, ...

autosuggest = Autosuggest.new(top_queries)

Filter duplicates

Stemming is used to detect duplicates like apple and apples.

The most popular query is preferred by default. To override this, use:

autosuggest.prefer ["apples"]

To fix false positives, use:

autosuggest.not_duplicates [["straws", "straus"]]

Filter misspellings

We tried open-source libraries like Aspell and Hunspell but quickly realized we needed to build a corpus specific to our application.

There are two ways to build the corpus, which can be used together.

1. Add words

  autosuggest.parse_words Product.pluck(:name)

Use the min option to only add words that appear multiple times.

1. Add concepts

  autosuggest.add_concept "brand", Brand.pluck(:name)

Filter words

Profanity is blocked by default. Add custom words with:

autosuggest.block_words ["boom"]

Profit

Get suggestions with:

autosuggest.suggestions

Filter queries without results and you’re set. We also prefer to have someone manually approve them by hand.

Full Example

top_queries = Search.group("LOWER(query)")
                    .having("COUNT(DISTINCT user_id) >= 5")
                    .count("DISTINCT user_id")
product_names = Product.pluck(:name)
brand_names = Brand.pluck(:name)

autosuggest = Autosuggest.new(top_queries)
autosuggest.parse_words product_names
autosuggest.add_concept "brand", brand_names
autosuggest.prefer brand_names
autosuggest.not_duplicates [["straws", "straus"]]
autosuggest.block_words ["boom"]

puts autosuggest.pretty_suggestions
# or
suggestions = autosuggest.suggestions

History

View the changelog

Contributing

Everyone is encouraged to help improve this project. Here are a few ways you can help:

• Report bugs
• Fix bugs and submit pull requests
• Write, clarify, or fix documentation
• Suggest or add new features

To get started with development:

git clone https://github.com/ankane/autosuggest.git
cd autosuggest
bundle install
bundle exec rake test