SwiftLint/Source/SwiftLintBuiltInRules/Rules/Lint/DiscouragedDirectInitRule.swift

import SwiftSyntax

@SwiftSyntaxRule
struct DiscouragedDirectInitRule: Rule {
    var configuration = DiscouragedDirectInitConfiguration()

    static let description = RuleDescription(
        identifier: "discouraged_direct_init",
        name: "Discouraged Direct Initialization",
        description: "Discouraged direct initialization of types that can be harmful",
        kind: .lint,
        nonTriggeringExamples: [
            Example("let foo = UIDevice.current"),
            Example("let foo = Bundle.main"),
            Example("let foo = Bundle(path: \"bar\")"),
            Example("let foo = Bundle(identifier: \"bar\")"),
            Example("let foo = Bundle.init(path: \"bar\")"),
            Example("let foo = Bundle.init(identifier: \"bar\")"),
            Example("let foo = NSError(domain: \"bar\", code: 0)"),
            Example("let foo = NSError.init(domain: \"bar\", code: 0)"),
            Example("func testNSError()"),
        ],
        triggeringExamples: [
            Example("↓UIDevice()"),
            Example("↓Bundle()"),
            Example("let foo = ↓UIDevice()"),
            Example("let foo = ↓Bundle()"),
            Example("let foo = ↓NSError()"),
            Example("let foo = bar(bundle: ↓Bundle(), device: ↓UIDevice(), error: ↓NSError())"),
            Example("↓UIDevice.init()"),
            Example("↓Bundle.init()"),
            Example("↓NSError.init()"),
            Example("let foo = ↓UIDevice.init()"),
            Example("let foo = ↓Bundle.init()"),
            Example("let foo = bar(bundle: ↓Bundle.init(), device: ↓UIDevice.init(), error: ↓NSError.init())"),
        ]
    )
}

private extension DiscouragedDirectInitRule {
    final class Visitor: ViolationsSyntaxVisitor<ConfigurationType> {
        override func visitPost(_ node: FunctionCallExprSyntax) {
            guard node.arguments.isEmpty, node.trailingClosure == nil,
                  configuration.discouragedInits.contains(node.calledExpression.trimmedDescription) else {
                return
            }

            violations.append(node.positionAfterSkippingLeadingTrivia)
        }
    }
}