Add Tokamak project linter

[hodovani]

Create command-line util to lint projects that use Tokamak.

Todo:

• Add Linter.md for linter documentation
• Verify that SwiftSyntax 0.5 is able to parse the Example project
• Add lint error Props is not Equatable
• Add unit-tests to lint functions
• Add lintFile -> [LintError]
• Make lintFolder use lintFile
• Make error output more user readable
• Fix TokamakLint types access scope: remove public from TokenVisitor, Rule, Reporter, PropsIsEquatableRule
• Fix TokenVisitor handling of Range, start and end are always equal to each other:

    node.range.startRow = row
    node.range.startColumn = column
    node.range.endRow = row
    node.range.endColumn = column

• Fix processToken, kind variable is unused:

  private func processToken(_ token: TokenSyntax) {
    var kind = "\(token.tokenKind)"
    if let index = kind.firstIndex(of: "(") {
      kind = String(kind.prefix(upTo: index))
    }
    if kind.hasSuffix("Keyword") {
      kind = "keyword"
    }

    column += token.text.count
  }

• Fix walkAndGrab, make it private, remove if node.children.count > 0 condition
• Investigate if SwiftCLI package can be used in TokamakCLI module
• Rename TokamakCLI to tokamak in Package.swift for Swift 5.0 and 4.2

.executable(name: "tokamak", targets: ["TokamakCLI"])

• Lint "Only one render in component"
• One render function rule should check all components, not only hooked components.
• Lint "Rules of Hooks"
• Lint "Components can only be declared as structs"
• Integrate swift-log package
• Remove direct usage of print, implement configurable output for stdout or files with a custom LogHandler implementation for swift-log

Long-term:

• Lint "Arguments order"
• Lint "Unused argument: hooks, children"
• Lint "Declare non-static properties and functions in component"
• Lint Rules of Hooks within extensions for all Hooks, not just state

[MaxDesiatov]

Closing as outdated