https://github.com/lipanski/sql-spy
A gem to track all SQL queries performed inside a block of code.
https://github.com/lipanski/sql-spy
activerecord debug gem gems minitest query rspec ruby spy sql
Last synced: 24 days ago
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A gem to track all SQL queries performed inside a block of code.
- Host: GitHub
- URL: https://github.com/lipanski/sql-spy
- Owner: lipanski
- License: mit
- Created: 2020-10-05T17:58:27.000Z (over 4 years ago)
- Default Branch: master
- Last Pushed: 2023-11-24T09:42:10.000Z (over 1 year ago)
- Last Synced: 2025-03-24T12:21:46.688Z (about 1 month ago)
- Topics: activerecord, debug, gem, gems, minitest, query, rspec, ruby, spy, sql
- Language: Ruby
- Homepage:
- Size: 24.4 KB
- Stars: 27
- Watchers: 2
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE.txt
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README
# SqlSpy
A gem to track all SQL queries performed inside a block of code.
With **SqlSpy** you can test:
- The total amount of queries performed by a piece of code
- The amount of queries performed on a specific table
- The type of these queries: *SELECT*, *INSERT*, *UPDATE*, *DELETE*
- The query duration
- The SQL produced by your *ActiveRecord* code
- N+1 queries
The implementation is inspired by how [ActiveRecord is tested](https://github.com/rails/rails/blob/6-0-stable/activerecord/test/cases/test_case.rb).
Check out [my blog post](https://lipanski.com/posts/activerecord-eager-loading#preventing-n1-regressions-with-tests) about writing controller tests with **SqlSpy** in order to prevent N+1 regressions.
## Usage
Add the gem to your `Gemfile`:
```ruby
gem "sql_spy"
```
Install it:
```sh
bundle install
```
Wrap the code you'd like to track inside `SqlSpy.track {}`:
```ruby
require "sql_spy"
queries = SqlSpy.track do
# Some code that triggers ActiveRecord queries
end
```
The `SqlSpy.track` method will return **an array containing all the queries performed inside the block**. Every object inside this array exposes the following **methods**:
- `#model_name`: The model name (e.g. "User").
- `#sql`: The SQL query that was performed.
- `#duration`: The duration of the query in milliseconds.
- `#select?`: Is this a *SELECT* query?
- `#insert?`: Is this an *INSERT* query?
- `#update?`: Is this an *UPDATE* query?
- `#delete?`: Is this a *DELETE* query?
Here are some **ideas** of how you could use this:
```ruby
# Expect less than 5 queries
assert queries.count < 5
# Expect 1 INSERT query
assert_equal 1, queries.select(&:insert?).size
# Expect 2 queries to the posts table
assert_equal 2, queries.select { |query| query.model_name == "Post" }.size
# None of the queries should be slower than 100ms
assert queries.none? { |query| query.duration > 100 }
# Fail on N+1 queries: expect at most 1 query per table
queries_by_model = queries.group_by(&:model_name)
assert queries_by_model.none? { |model_name, queries| queries.count > 1 }
```
## Development
The gem is tested with Postgres 9.6 and SQLite 3.
To run tests with SQLite:
```sh
rake
```
To run tests with Postgres:
```sh
# Create a test database
cretedb sql_spy_test
DATABASE_URL=postgres:///sql_spy_test rake
```
## License
The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).