SwiftLint/Source/SwiftLintFramework/Rules/Idiomatic/DuplicateImportsRule.swift

110 lines
4.0 KiB
Swift

import Foundation
import SourceKittenFramework
public struct DuplicateImportsRule: ConfigurationProviderRule, AutomaticTestableRule {
public var configuration = SeverityConfiguration(.warning)
// List of all possible import kinds
static let importKinds = [
"typealias", "struct", "class",
"enum", "protocol", "let",
"var", "func"
]
public init() {}
public static let description = RuleDescription(
identifier: "duplicate_imports",
name: "Duplicate Imports",
description: "Imports should be unique.",
kind: .idiomatic,
nonTriggeringExamples: DuplicateImportsRuleExamples.nonTriggeringExamples,
triggeringExamples: DuplicateImportsRuleExamples.triggeringExamples
)
private func rangesInConditionalCompilation(file: SwiftLintFile) -> [ByteRange] {
let contents = file.stringView
let ranges = file.syntaxMap.tokens
.filter { $0.kind == .buildconfigKeyword }
.map { $0.range }
.filter { range in
return ["#if", "#endif"].contains(contents.substringWithByteRange(range))
}
// Make sure that each #if has corresponding #endif
guard ranges.count % 2 == 0 else { return [] }
return stride(from: 0, to: ranges.count, by: 2).reduce(into: []) { result, rangeIndex in
result.append(ranges[rangeIndex].union(with: ranges[rangeIndex + 1]))
}
}
public func validate(file: SwiftLintFile) -> [StyleViolation] {
let contents = file.stringView
let ignoredRanges = self.rangesInConditionalCompilation(file: file)
let importKinds = DuplicateImportsRule.importKinds.joined(separator: "|")
// Grammar of import declaration
// attributes(optional) import import-kind(optional) import-path
let regex = "^(\\w\\s)?import(\\s(\(importKinds)))?\\s+[a-zA-Z0-9._]+$"
let importRanges = file.match(pattern: regex)
.filter { $0.1.allSatisfy { [.keyword, .identifier].contains($0) } }
.compactMap { contents.NSRangeToByteRange(start: $0.0.location, length: $0.0.length) }
.filter { importRange -> Bool in
return !importRange.intersects(ignoredRanges)
}
let lines = file.lines
let importLines: [Line] = importRanges.compactMap { range in
guard let line = contents.lineAndCharacter(forByteOffset: range.location)?.line
else { return nil }
return lines[line - 1]
}
var violations = [StyleViolation]()
for indexI in 0..<importLines.count {
for indexJ in indexI + 1..<importLines.count {
let firstLine = importLines[indexI]
let secondLine = importLines[indexJ]
guard firstLine.areImportsDuplicated(with: secondLine)
else { continue }
let lineWithDuplicatedImport: Line = {
if firstLine.importIdentifier?.count ?? 0 <= secondLine.importIdentifier?.count ?? 0 {
return secondLine
} else {
return firstLine
}
}()
let location = Location(file: file, characterOffset: lineWithDuplicatedImport.range.location)
let violation = StyleViolation(ruleDescription: type(of: self).description, location: location)
violations.append(violation)
}
}
return violations
}
}
private extension Line {
/// Returns name of the module being imported.
var importIdentifier: Substring? {
return self.content.split(separator: " ").last
}
func areImportsDuplicated(with otherLine: Line) -> Bool {
guard let firstImportIdentifiers = self.importIdentifier?.split(separator: "."),
let secondImportIdentifiers = otherLine.importIdentifier?.split(separator: ".")
else { return false }
return zip(firstImportIdentifiers, secondImportIdentifiers).allSatisfy { $0 == $1 }
}
}