DiscouragedObjectLiteralRule.swift

//
//  DiscouragedObjectLiteralRule.swift
//  SwiftLint
//
//  Created by Ornithologist Coder on 1/3/18.
//  Copyright © 2018 Realm. All rights reserved.
//

import Foundation
import SourceKittenFramework

public struct DiscouragedObjectLiteralRule: ASTRule, OptInRule, ConfigurationProviderRule {
    public var configuration = SeverityConfiguration(.warning)

    public init() {}

    public static let description = RuleDescription(
        identifier: "discouraged_object_literal",
        name: "Discouraged Object Literal",
        description: "Prefer initializers over object literals.",
        kind: .idiomatic,
        nonTriggeringExamples: [
            "let image = UIImage(named: aVariable)",
            "let image = UIImage(named: \"interpolated \\(variable)\")",
            "let color = UIColor(red: value, green: value, blue: value, alpha: 1)",
            "let image = NSImage(named: aVariable)",
            "let image = NSImage(named: \"interpolated \\(variable)\")",
            "let color = NSColor(red: value, green: value, blue: value, alpha: 1)"
        ],
        triggeringExamples: [
            "let image = ↓#imageLiteral(resourceName: \"image.jpg\")",
            "let color = ↓#colorLiteral(red: 0.9607843161, green: 0.7058823705, blue: 0.200000003, alpha: 1)"
        ]
    )

    public func validate(file: File,
                         kind: SwiftExpressionKind,
                         dictionary: [String: SourceKitRepresentable]) -> [StyleViolation] {
        guard let offset = dictionary.offset, kind == .objectLiteral else { return [] }

        return [StyleViolation(ruleDescription: type(of: self).description,
                               severity: configuration.severity,
                               location: Location(file: file, byteOffset: offset))]
    }
}