This PR improves the error handling of the code fence removal transform stream by catching errors thrown by the `removeFencedCode` function and passing them to the `end` callback. This appears to resolve a problem where watched builds would blow up whenever a file with fences was reloaded.
This PR enables the exclusion of JavaScript and JSON source by `buildType`, and enables the running of `eslint` under LavaMoat. 80-90% of the changes in this PR are `.patch` files and LavaMoat policy additions.
The file exclusion is designed to work in conjunction with our code fencing. If you forget to fence an import statement of an excluded file, the application will now error on boot. **This PR commits us to a particular naming convention for files intended only for certain builds.** Continue reading for details.
### Code Fencing and ESLint
When a file is modified by the code fencing transform, we run ESLint on it to ensure that we fail early for syntax-related issues. This PR adds the first code fences that will be actually be removed in production builds. As a consequence, this was also the first time we attempted to run ESLint under LavaMoat. Making that work required a lot of manual labor because of ESLint's use of dynamic imports, but the manual changes necessary were ultimately quite minor.
### File Exclusion
For all builds, any file in `app/`, `shared/` or `ui/` in a sub-directory matching `**/${otherBuildType}/**` (where `otherBuildType` is any build type except `main`) will be added to the list of excluded files, regardless of its file extension. For example, if we want to add one or more pages to the UI settings in Flask, we'd create the folder `ui/pages/settings/flask`, add any necessary files or sub-folders there, and fence the import statements for anything in that folder. If we wanted the same thing for Beta, we would name the directory `ui/pages/settings/beta`.
As it happens, we already organize some of our source files in this way, namely the logo JSON for Beta and Flask builds. See `ui/helpers/utils/build-types.js` to see how this works in practice.
Because the list of ignored filed is only passed to `browserify.exclude()`, any files not bundled by `browserify` will be ignored. For our purposes, this is mostly relevant for `.scss`. Since we don't have anything like code fencing for SCSS, we'll have to consider how to handle our styles separately.
The code fence transform was including contents after the final END directive twice. That was not covered by the tests, because none of the examples contained any content after the final END directive, and concatenating the empty string twice does not produce an observable difference in the test results.
This bug was due to an off-by-one error in the loop of the multiSplice function. The error has been fixed, and more test cases have been added.
The build type (i.e. the distribution) is now included in the Sentry
environment during setup, for all builds except the "main" build. This
will allow us to track Flask and beta errors separately from other
errors.
A constant was created for the build types. The equivalent constant in
our build scripts was updated to match it more closely, for
consistency. We can't use the same constant in both places because our
shared constants are in modules that use ES6 exports, and our build
script does not yet support ES6 exports.
The singular `BuildType` was used rather than `BuildTypes` to match our
naming conventions elsewhere for enums. We name them like classes or
types, rather than like a collection.
Relates to #11896
This PR adds build-time code exclusion by means of code fencing. For details, please see the README in `./development/build/transforms`. Note that linting of transformed files as a form of validation is added in a follow-up, #12075.
Hopefully exhaustive tests are added to ensure that the transform works according to its specification. Since these tests are Node-only, they required their own Jest config. The recommended way to work with multiple Jest configs is using the `projects` field in the Jest config, however [that feature breaks coverage collection](https://github.com/facebook/jest/issues/9628). That being the case, I had to set up two separate Jest configs. In order to get both test suites to run in parallel, Jest is now invoked via a script, `./test/run-jest.sh`.
By way of example, this build system feature allows us to add fences like this:
```javascript
this.store.updateStructure({
...,
GasFeeController: this.gasFeeController,
TokenListController: this.tokenListController,
///: BEGIN:ONLY_INCLUDE_IN(beta)
PluginController: this.pluginController,
///: END:ONLY_INCLUDE_IN
});
```
Which at build time are transformed to the following if the build type is not `beta`:
```javascript
this.store.updateStructure({
...,
GasFeeController: this.gasFeeController,
TokenListController: this.tokenListController,
});
```
Co-authored-by: Mark Stacey <markjstacey@gmail.com>
