JS assets added by plugins via `register_asset` will be outside the `assets/javascripts` directory, and are therefore exempt from being transpiled. That means that there isn't really any need to run them through DiscourseJsProcessor. Instead, we can just concatenate them together, and avoid the need for all the sprockets-wrangling.
This commit also takes the opportunity to clean up a number of plugin-asset-related codepaths which are no longer required (e.g. globs, handlebars)
While we are unable to support OAUTH2 with pop3 (due to upstream dependency ruby/net-pop#16), we are adding the support for mail pollers plugin. Doing so, it would be possible to write a plugin which then uses other ways (microsoft graph sdk for example) to poll emails from a mailbox.
The idea is that a plugin would define a class which inherits from Email::Poller and defines a poll_mailbox static method which returns an array of strings. Then the plugin could call register_mail_poller(<class_name>) to have it registered. All the configuration (oauth2 tokens, email, etc) could be managed by sitesettings defined in the plugin.
Introduces a new API for plugin data modification without class-based extension overhead.
This commit introduces a new API that allows plugins to modify data in cases where they return different data rather than additional data, as is common with filtered_registers in DiscoursePluginRegistry. This API removes the need for defining class-based extension points.
When a plugin registers a modifier, it will automatically be called if the plugin is enabled. The core will then modify the parameter sent to it using the block registered by the plugin:
```ruby
DiscoursePluginRegistry.register_modifier(plugin_instance, :magic_sum_modifier) { |a, b| a + b }
sum = DiscoursePluginRegistry.apply_modifier(:magic_sum_filter, 1, 2)
expect(sum).to eq(3)
```
Key features of these modifiers:
- Operate in a stack (first registered, first called)
- Automatically disabled when the plugin is disabled
- Pass the cumulative result of all block invocations to the caller
It's very easy to forget to add `require 'rails_helper'` at the top of every core/plugin spec file, and omissions can cause some very confusing/sporadic errors.
By setting this flag in `.rspec`, we can remove the need for `require 'rails_helper'` entirely.
