How to use start method of BasicOperation class

...81        op.completionBlock = {82            completionBlockExp.fulfill()83        }84        85        op.start()86        87        wait(for: [completionBlockExp], timeout: 0.5)88        89        // state90        XCTAssertTrue(op.isFinished)91        XCTAssertFalse(op.isCancelled)92        XCTAssertFalse(op.isExecuting)93        // progress94        XCTAssertTrue(op.progress.isFinished)95        XCTAssertFalse(op.progress.isCancelled)96        XCTAssertEqual(op.progress.fractionCompleted, 1.0)97        XCTAssertFalse(op.progress.isIndeterminate)98        99    }100    101    /// Test as a standalone operation. Do not run it.102    func testOpNotRun() {103        104        let op = TestBasicOperation()105        106        let completionBlockExp = expectation(description: "Completion Block Called")107        completionBlockExp.isInverted = true108        109        op.completionBlock = {110            completionBlockExp.fulfill()111        }112        113        wait(for: [completionBlockExp], timeout: 0.3)114        115        // state116        XCTAssertTrue(op.isReady)117        XCTAssertFalse(op.isFinished)118        XCTAssertFalse(op.isCancelled)119        XCTAssertFalse(op.isExecuting)120        // progress121        XCTAssertFalse(op.progress.isFinished)122        XCTAssertFalse(op.progress.isCancelled)123        XCTAssertEqual(op.progress.fractionCompleted, 0.0)124        XCTAssertFalse(op.progress.isIndeterminate)125        126    }127    128    /// Test as a standalone operation. Cancel it before it runs.129    func testOpCancelBeforeRun() {130        131        let op = TestBasicOperation()132        133        let completionBlockExp = expectation(description: "Completion Block Called")134        135        op.completionBlock = {136            completionBlockExp.fulfill()137        }138        139        op.cancel()140        op.start() // in an OperationQueue, all operations must start even if they're already cancelled141        142        wait(for: [completionBlockExp], timeout: 0.3)143        144        // state145        XCTAssertTrue(op.isReady)146        XCTAssertTrue(op.isFinished)147        XCTAssertTrue(op.isCancelled)148        XCTAssertFalse(op.isExecuting)149        // progress150        XCTAssertTrue(op.progress.isFinished)151        XCTAssertTrue(op.progress.isCancelled)152        XCTAssertEqual(op.progress.fractionCompleted, 1.0)153        XCTAssertFalse(op.progress.isIndeterminate)154        155    }156    157    /// Test in the context of an OperationQueue. Run is implicit.158    @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)159    func testQueue() {160        161        let opQ = OperationQueue()162        163        let op = TestBasicOperation()164        165        let completionBlockExp = expectation(description: "Completion Block Called")166        167        op.completionBlock = {168            completionBlockExp.fulfill()169        }170        171        // must manually increment for OperationQueue172        opQ.progress.totalUnitCount += 1173        // queue automatically starts the operation once it's added174        opQ.addOperation(op)175        176        wait(for: [completionBlockExp], timeout: 0.5)177        178        // state179        XCTAssertEqual(opQ.operationCount, 0)180        XCTAssertTrue(op.isFinished)181        XCTAssertFalse(op.isCancelled)182        XCTAssertFalse(op.isExecuting)183        // progress - operation184        XCTAssertTrue(op.progress.isFinished)185        XCTAssertFalse(op.progress.isCancelled)186        XCTAssertEqual(op.progress.fractionCompleted, 1.0)187        XCTAssertFalse(op.progress.isIndeterminate)188        // progress - queue189        XCTAssertTrue(opQ.progress.isFinished)190        XCTAssertFalse(opQ.progress.isCancelled)191        XCTAssertEqual(opQ.progress.fractionCompleted, 1.0)192        XCTAssertFalse(opQ.progress.isIndeterminate)193        194    }195    196    /// Test that start() runs synchronously. Run it.197    func testOp_SynchronousTest_Run() {198        199        let completionBlockExp = expectation(description: "Completion Block Called")200        201        // after start(), will mutate self after 500ms then finish202        let op = TestDelayedMutatingBasicOperation(initial: 0,203                                                   changeTo: 1)204        205        op.completionBlock = {206            completionBlockExp.fulfill()207        }208        209        op.start()210        211        XCTAssertEqual(op.val, 1)212        213        // state214        XCTAssertTrue(op.isFinished)215        XCTAssertFalse(op.isCancelled)216        XCTAssertFalse(op.isExecuting)217        // progress218        XCTAssertTrue(op.progress.isFinished)219        XCTAssertFalse(op.progress.isCancelled)220        XCTAssertEqual(op.progress.fractionCompleted, 1.0)221        XCTAssertFalse(op.progress.isIndeterminate)222        223        wait(for: [completionBlockExp], timeout: 2)...

...7import OTAtomics8/// A synchronous or asynchronous `Operation` subclass that provides essential boilerplate.9/// `BasicOperation` is designed to be subclassed.10///11/// By default this operation is synchronous. If the operation is run without being inserted into an `OperationQueue`, when you call the `start()` method the operation executes immediately in the current thread. By the time the `start()` method returns control, the operation is complete.12///13/// If asynchronous behavior is required then use `BasicAsyncOperation` instead.14///15/// **Usage**16///17/// This object is designed to be subclassed.18///19/// Refer to the following example for calls that must be made within the main closure block:20///21///     class MyOperation: BasicOperation {22///         override func main() {23///             // At the start, call this and conditionally return:24///             guard mainShouldStart() else { return }25///26///             // ... do some work ...27///28///             // Optionally:29///             // If the operation may take more than a few seconds,30///             // periodically check and and return early:31///             if mainShouldAbort() { return }32///33///             // ... do some work ...34///35///             // Finally, at the end of the operation call:36///             completeOperation()37///         }38///     }39///40/// - important: This object is designed to be subclassed. See the Foundation documentation for `Operation` regarding overriding `start()` and be sure to follow the guidelines in these inline docs regarding `BasicOperation` specifically.41open class BasicOperation: Operation, ProgressReporting {42    43    // MARK: - Progress44    45    /// Progress object representing progress of the operation.46    public private(set) var progress: Progress = LabelProgress(totalUnitCount: 1)47   48    /// Return `.progress` typed as `LabelProgress` in order to get or set label information.49    public final var labelProgress: LabelProgress {50        51        progress as! LabelProgress52        53    }54    55    /// Progress weight when the operation is added to a `BasicOperationQueue` or one of its subclasses.56    public var progressWeight: BasicOperationQueue.ProgressWeight57    58    // MARK: - KVO59    60    // adding KVO compliance61    @objc dynamic62    public final override var isExecuting: Bool { _isExecuting }63    @OTAtomicsThreadSafe private var _isExecuting = false {64        willSet { willChangeValue(for: \.isExecuting) }65        didSet { didChangeValue(for: \.isExecuting) }66    }67    68    // adding KVO compliance69    @objc dynamic70    public final override var isFinished: Bool { _isFinished }71    @OTAtomicsThreadSafe private var _isFinished = false {72        willSet { willChangeValue(for: \.isFinished) }73        didSet { didChangeValue(for: \.isFinished) }74    }75    76    // adding KVO compliance77    @objc dynamic78    public final override var qualityOfService: QualityOfService {79        get { _qualityOfService }80        set { _qualityOfService = newValue }81    }82    private var _qualityOfService: QualityOfService = .default {83        willSet { willChangeValue(for: \.qualityOfService) }84        didSet { didChangeValue(for: \.qualityOfService) }85    }86    87    public init(label: String? = nil,88                weight: BasicOperationQueue.ProgressWeight = .default()) {89        90        progressWeight = weight91        super.init()92        93        if label != nil { labelProgress.label = label }94        95        progress.cancellationHandler = { [weak progress] in96            guard let progress = progress else { return }97            98            // automatically set progress to finished state if cancelled99            progress.completedUnitCount = progress.totalUnitCount100        }101    }102    103    // MARK: - Method Overrides104    105    public final override func start() {106        if isCancelled { completeOperation(dueToCancellation: true) }107        super.start()108    }109    110    public final override func cancel() {111        super.cancel()112        progress.cancel()113    }114    115    // MARK: - Methods116    117    /// Returns true if operation should begin.118    public final func mainShouldStart() -> Bool {119        120        guard !isCancelled else {121            completeOperation(dueToCancellation: true)...

1let operation = BasicOperation()2operation.start()3let operation = BasicOperation()4operation.start()5let operation = BasicOperation()6operation.start()7let operation = BasicOperation()8operation.start()9let operation = BasicOperation()10operation.start()11let operation = BasicOperation()12operation.start()13class BasicOperation {14    func start() {15        print("Started")16    }17}18Then in your other files you can import the Operation.swift file and use the start method:19import Operation20let operation = BasicOperation()21operation.start()22import Operation23let operation = BasicOperation()24operation.start()25import Operation26let operation = BasicOperation()27operation.start()

1var basicOperation = BasicOperation()2basicOperation.start()3var basicOperation = BasicOperation()4basicOperation.start()5var basicOperation = BasicOperation()6basicOperation.start()7var basicOperation = BasicOperation()8basicOperation.start()9var basicOperation = BasicOperation()10basicOperation.start()11var basicOperation = BasicOperation()12basicOperation.start()13var basicOperation = BasicOperation()14basicOperation.start()15var basicOperation = BasicOperation()16basicOperation.start()17var basicOperation = BasicOperation()18basicOperation.start()19var basicOperation = BasicOperation()20basicOperation.start()21var basicOperation = BasicOperation()22basicOperation.start()23var basicOperation = BasicOperation()24basicOperation.start()25var basicOperation = BasicOperation()26basicOperation.start()27var basicOperation = BasicOperation()28basicOperation.start()29var basicOperation = BasicOperation()30basicOperation.start()31var basicOperation = BasicOperation()32basicOperation.start()33var basicOperation = BasicOperation()34basicOperation.start()

1let operation = BasicOperation()2operation.start()3let operation = BasicOperation()4operation.start()5let operation = BasicOperation()6operation.start()7let operation = BasicOperation()8operation.start()9let operation = BasicOperation()10operation.start()11let operation = BasicOperation()12operation.start()13let operation = BasicOperation()14operation.start()15let operation = BasicOperation()16operation.start()17let operation = BasicOperation()18operation.start()19let operation = BasicOperation()20operation.start()21let operation = BasicOperation()22operation.start()23let operation = BasicOperation()24operation.start()25let operation = BasicOperation()26operation.start()27let operation = BasicOperation()28operation.start()29let operation = BasicOperation()30operation.start()31let operation = BasicOperation()32operation.start()33let operation = BasicOperation()34operation.start()35let operation = BasicOperation()36operation.start()37let operation = BasicOperation()38operation.start()

1let basicOperation = BasicOperation()2basicOperation.start()3let basicOperation = BasicOperation()4basicOperation.start()5let basicOperation = BasicOperation()6basicOperation.start()7let basicOperation = BasicOperation()8basicOperation.start()9let basicOperation = BasicOperation()10basicOperation.start()11let basicOperation = BasicOperation()12basicOperation.start()13let basicOperation = BasicOperation()14basicOperation.start()15let basicOperation = BasicOperation()16basicOperation.start()17let basicOperation = BasicOperation()18basicOperation.start()19let basicOperation = BasicOperation()20basicOperation.start()21let basicOperation = BasicOperation()22basicOperation.start()23let basicOperation = BasicOperation()24basicOperation.start()25let basicOperation = BasicOperation()26basicOperation.start()27let basicOperation = BasicOperation()28basicOperation.start()29let basicOperation = BasicOperation()30basicOperation.start()31let basicOperation = BasicOperation()32basicOperation.start()33let basicOperation = BasicOperation()34basicOperation.start()

1import Foundation2let basicOperation = BasicOperation()3basicOperation.start()4import Foundation5let basicOperation = BasicOperation()6basicOperation.start()7import Foundation8let basicOperation = BasicOperation()9basicOperation.start()10import Foundation11let basicOperation = BasicOperation()12basicOperation.start()13import Foundation14let basicOperation = BasicOperation()15basicOperation.start()16import Foundation17let basicOperation = BasicOperation()18basicOperation.start()19import Foundation20let basicOperation = BasicOperation()21basicOperation.start()22import Foundation23let basicOperation = BasicOperation()24basicOperation.start()25import Foundation26let basicOperation = BasicOperation()27basicOperation.start()28import Foundation29let basicOperation = BasicOperation()30basicOperation.start()31import Foundation32let basicOperation = BasicOperation()33basicOperation.start()34import Foundation35let basicOperation = BasicOperation()36basicOperation.start()37import Foundation38let basicOperation = BasicOperation()39basicOperation.start()40import Foundation41let basicOperation = BasicOperation()42basicOperation.start()43import Foundation44let basicOperation = BasicOperation()45basicOperation.start()46import Foundation47let basicOperation = BasicOperation()48basicOperation.start()

1class BasicOperation {2    init(name: String) {3    }4    func start() {5        print("start method of BasicOperation class")6    }7}8class AdvancedOperation: BasicOperation {9    override func start() {10        print("start method of AdvancedOperation class")11    }12}13let advancedOperation = AdvancedOperation(name: "Advanced Operation")14advancedOperation.start()15class BasicOperation {16    init(name: String) {17    }18    func start() {19        print("start method of BasicOperation class")20    }21}22class AdvancedOperation: BasicOperation {23    override func start() {24        super.start()25        print("start method of AdvancedOperation class")26    }27}28let advancedOperation = AdvancedOperation(name: "Advanced Operation")29advancedOperation.start()30class BasicOperation {31    init(name: String) {32    }33    func start() {34        print("start method of BasicOperation class")35    }36}37class AdvancedOperation: BasicOperation {38    override func start() {39        super.start()40        print("start method of AdvancedOperation class")41    }42}43let basicOperation = BasicOperation(name: "Basic Operation")44basicOperation.start()45class BasicOperation {46    init(name: String) {47    }48    func start() {49        print("start method of BasicOperation class")50    }51}52class AdvancedOperation: BasicOperation {53    override func start() {54        super.start()55        print("start method of AdvancedOperation class")56    }57}58let advancedOperation = AdvancedOperation(name: "Advanced Operation")59let basicOperation = BasicOperation(name: "Basic Operation")60basicOperation.start()61advancedOperation.start()62class BasicOperation {63    init(name: String) {64    }65    func start() {66        print("start method of BasicOperation class")67    }68}69class AdvancedOperation: BasicOperation {70    override func start() {

1var op = BasicOperation()2op.start()3var op = BasicOperation()4op.start()5var op = BasicOperation()6op.start()7var op = BasicOperation()8op.start()9var op = BasicOperation()10op.start()11var op = BasicOperation()12op.start()13var op = BasicOperation()14op.start()15var op = BasicOperation()16op.start()17var op = BasicOperation()18op.start()19var op = BasicOperation()20op.start()21var op = BasicOperation()22op.start()23var op = BasicOperation()24op.start()25var op = BasicOperation()26op.start()27var op = BasicOperation()

1let operation = BasicOperation()2operation.start()3let operation = BasicOperation()4operation.start()5let operation = BasicOperation()6operation.start()7let operation = BasicOperation()8operation.start()9let operation = BasicOperation()10operation.start()11let operation = BasicOperation()12operation.start()13let operation = BasicOperation()14operation.start()15let operation = BasicOperation()16operation.start()17let operation = BasicOperation()18operation.start()19let operation = BasicOperation()20operation.start()21let operation = BasicOperation()22operation.start()