This cuts down on the boilerplate involved in writing SwiftSyntax-based
rules. May not be significant right now since most rules are still built
with SourceKit, but as we migrate more rules moving forward, this should
make it easier for rule authors to write rules that behave performantly
and correctly.
* Improve docstrings for `StringView+SwiftSyntax.swift`
* Move changelog entry to correct section & reword
* Change parameter type from `Int` to `ByteCount`
* Move AbsolutePosition / ByteCount conversion to internal API
* Only warn once if syntax tree cannot be parsed
* Move Syntactic Sugar examples to a dedicated file
* Change SyntacticSugarRuleVisitor from SyntaxAnyVisitor to SyntaxVisitor
* Add `SugaredType` enum to help with the implement `SyntacticSugarRule`
We've tried adding Swift Syntax support to SwiftLint in the past but had to turn it off in https://github.com/realm/SwiftLint/pull/3107 due to distribution and portability issues.
With https://github.com/keith/StaticInternalSwiftSyntaxParser it should be possible to avoid those issues by statically linking the internal Swift syntax parser so it's available no matter where users have Xcode installed on their computer.
By removing all calls to SourceKit (collecting comment commands + checking the current Swift version), there's a really significant performance improvement.
| Framework | Mean [ms] | Min [ms] | Max [ms] | Relative |
|:---|---:|---:|---:|---:|
| SourceKit | 517.8 ± 8.3 | 505.5 | 531.1 | 6.59 ± 0.43 |
| SwiftSyntax | 78.6 ± 5.0 | 72.6 | 92.1 | 1.00 |
In practice, the SourceKit overhead will continue being there for as long as any rule being run is still looking up the SwiftLint syntax map though.
* Add Example wrapper in order to display test failures inline when running in Xcode.
* Stop using Swift 5.1-only features so we can compile on Xcode 10.2.
* Wrap strings in Example.
* Add Changelog entry.
* Wrap all examples in Example struct.
* Better and more complete capturing of line numbers.
* Fix broken test.
* Better test traceability.
* Address or disable linting warnings.
* Add documentation comments.
* Disable linter for a few cases.
* Limit mutability and add copy-and-mutate utility functions.
* Limit scope of mutability.
Danny Mösch