Snapshot+Bazel.swift

import Foundation
import SnapshotTesting
import XCTest

func assertBundledSnapshot<Value, Format>(
    of value: @autoclosure () throws -> Value,
    as snapshotting: Snapshotting<Value, Format>,
    named name: String? = nil,
    record recording: Bool? = nil,
    timeout: TimeInterval = 5,
    fileID: StaticString = #fileID,
    file filePath: StaticString = #filePath,
    testName: String = #function,
    line: UInt = #line,
    column: UInt = #column
) {
    let snapshotDirectory = getSnapshotDirectory(filePath: filePath)?.path
    let failure = verifySnapshot(
        of: try value(),
        as: snapshotting,
        named: name,
        record: recording,
        snapshotDirectory: snapshotDirectory,
        timeout: timeout,
        fileID: fileID,
        file: filePath,
        testName: testName,
        line: line,
        column: column
    )
    guard let message = failure else { return }
    XCTFail(message, file: filePath, line: line)
}

// MARK: - Private

private func getSnapshotDirectory(filePath: StaticString) -> URL? {
    let currentBundle = Bundle(for: CurrentBundleFinder.self)
    guard
        let snapshotBundleURL = currentBundle.resourceURL?.appendingPathComponent("Snapshots.bundle"),
        let snapshotBundle = Bundle(url: snapshotBundleURL),
        let snapshotResourceURL = snapshotBundle.resourceURL
    else {
        return nil
    }

    let fileURL = URL(fileURLWithPath: "\(filePath)", isDirectory: false)
    let fileName = fileURL.deletingPathExtension().lastPathComponent
    let snapshotDirectory = snapshotResourceURL
        .appendingPathComponent("__Snapshots__")
        .appendingPathComponent(fileName)

    var isDirectory: ObjCBool = false
    if FileManager.default.fileExists(atPath: snapshotDirectory.path, isDirectory: &isDirectory), isDirectory.boolValue == true {
        return snapshotDirectory
    } else {
        return nil
    }
}

private class CurrentBundleFinder {}