In development we regularly restart/reload Rails, which wipes out the schema cache. This then has to be regenerated using DDL queries on the database.
Instead, we can make use of the `rake db:schema:cache:dump` command. This will dump the schema cache to a YAML file, and then load it when needed. This is significantly faster than rebuilding the cache from DDL queries every time.
On every request, Rails checks to see whether any ruby code has been changed on the filesystem. The default FileUpdateChecker does this by iterating over every file on the autoload_paths and comparing its modified-time.
In Discourse, our autoload path of `/app` includes the `/app/assets` directory, and therefore thousands of non-ruby files (e.g. node_modules). This makes the `Dir["/app"]` call very slow (>100ms in my case). On my machine, every Rails-handled request spends around 150-200ms in the FileUpdateChecker. This commit introduces a couple of changes to completely eliminate this wasted time:
- The `/app/assets` directory is excluded from the file watchers. For me, this cut the time spent in the file_watcher to around 50-100ms
- Switches our development config to use the `EventedFileUpdateChecker`, which makes use of the `listen` gem to subscribe to os-specific notifications of changes. This completely removes the `FileUpdateChecker` from the critical path
On my machine, topic_list requests now return in around 80ms (previously >200ms). Live code reload still works as it did before
If RAILS_DISABLE_ACTIVERECORD_LOGS=1 is passed when starting Rails, none of the query log output will show. This is very useful for debugging with breakpoints because logs are not flooding in constantly.
byebug, ruby-prof, better_errors and rbtrace are very MRI specific, flag
them as such
This helps move forward on potential jruby and truffleruby experiments
- Refactor source_url to avoid using eval in development
- Precompile handlebars in development
- Include template compilers when running qunit
- Remove unsafe-eval in development CSP
- Include unsafe-eval only for qunit routes in development
From the better_errors README:
> Better Errors works by leaving a lot of context in server process memory. If you're using a web server that runs multiple "workers" it's likely that a second request (as happens when you click on a stack frame) will hit a different worker. That worker won't have the necessary context in memory, and you'll see a Session Expired message.
This renames the DISCOURSE_ENV_HOST var @eviltrout introduced in 95a9a544
to DISCOURSE_ENV_HOSTS and allows for a comma delimited list of hosts
This is useful for testing plugins and customized host names
Rails 6 seems to introduce a whitelist of allowed hosts. I personally
use `dev.local` for development and this no longer works.
This introduces a new ENV variable, `DISCOURSE_DEV_HOST`. If present,
it will whitelist that host for development mode.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
This change-set allows setting different defaults for different locales.
It also:
- Adds extensive testing around site setting validation
- raises deprecation error if site setting has the default property based on env
- relocated site settings for dev and tests in the initializer
- deprecated client_setting in the site setting's loading process
- ensure it raises when a enum site setting being set
- default_locale is promoted to `required` category.
- fixes incorrect default setting and validation
- fixes ensure type check for site settings
- creates a benchmark for site setting
- sets reasonable defaults for Chinese
This feature introduces the concept of themes. Themes are an evolution
of site customizations.
Themes introduce two very big conceptual changes:
- A theme may include other "child themes", children can include grand
children and so on.
- A theme may specify a color scheme
The change does away with the idea of "enabled" color schemes.
It also adds a bunch of big niceties like
- You can source a theme from a git repo
- History for themes is much improved
- You can only have a single enabled theme. Themes can be selected by
users, if you opt for it.
On a technical level this change comes with a whole bunch of goodies
- All CSS is now compiled using a custom pipeline that uses libsass
see /lib/stylesheet
- There is a single pipeline for css compilation (in the past we used
one for customizations and another one for the rest of the app
- The stylesheet pipeline is now divorced of sprockets, there is no
reliance on sprockets for CSS bundling
- CSS is generated with source maps everywhere (including themes) this
makes debugging much easier
- Our "live reloader" is smarter and avoid a flash of unstyled content
we run a file watcher in "puma" in dev so you no longer need to run
rake autospec to watch for CSS changes
This improves my DOMContentLoaded from 9s+ to less than 4s.
Pinging @SamSaffron on this because this was previously controversial.
This implementation adds the `@sourceURL` directive so chrome correctly
identifies the source files.
David Taylor
Vinoth Kannan
Martin Brennan
Vinoth Kannan
Penar Musaraj
Guo Xiang Tan
Sam Saffron
Robin Ward
Guo Xiang Tan
Erick Guan
Jay Pfaffman
Régis Hanol
Arpit Jalan
Akshay