Merge pull request #6 from Alexander-Ignition/swift_concurrency

Swift Concurrency

Author: Alexander-Ignition

Package.swift

@@ -6,7 +6,7 @@ import PackageDescription
 let package = Package(
     name: "XSTooling",
     platforms: [
-        .macOS(.v10_13),
+        .macOS(.v10_15),
     ],
     products: [
         .library(

Playgrounds/README.playground/Contents.swift

@@ -18,7 +18,7 @@ Supported tools:
 To use the `XSTooling` library in a SwiftPM project, add the following line to the dependencies in your `Package.swift` file:
 
 ```swift
-.package(url: "https://github.com/Alexander-Ignition/XSTooling", from: "0.0.1"),
+.package(url: "https://github.com/Alexander-Ignition/XSTooling", from: "0.0.2"),
 ```
 
 Include `"XSTooling"` as a dependency for your executable target:
@@ -34,25 +34,105 @@ Finally, add `import XSTooling` to your source code.
 ```swift
 import XSTooling
 
-let shell = Shell.sh
+let sh = Shell.default
+try await sh("swift build").run()
+```
+
+## Shell
+
+Shell command can be `run` or `read`.
+
+Read the shell command output.
+
+```swift
+let version = try await sh("xcodebuild -version").read().string
+```
+
+Run shell command with redirection to stdout and stderr.
+
+```swift
+try await sh("ls -al").run()
+```
+
+Redirection can be configured, for example, to write to a log file.
+
+```swift
+let url = URL(fileURLWithPath: "logs.txt", isDirectory: false)
+FileManager.default.createFile(atPath: url.path, contents: nil)
+let file = try FileHandle(forWritingTo: url)
+defer {
+    try! file.close()
+}
+try await sh("swift build").run(.output(file).error(file))
+```
+
+`Shell` has predefined instances.
+
+```swift
+Shell.default
+Shell.sh
+Shell.bash
+Shell.zsh
+```
+
+Conceptually, a `Shell` is a wrapper over a `ProcessCommand`. 
 
-let path = try shell("pwd").string
-let files = try shell("ls").lines
+- `sh.command` contains common parameters for all commands.
+- `sh("ls")` each call to this method returned a copy of the `ProcessCommand` with additional arguments
+
+```swift
+sh = Shell.default
+sh.command // ProcessCommand
+sh.command.environment // [String: String]?
+sh.command.currentDirectoryURL // URL?
+sh("ls") // ProcessCommand
+```
+
+## ProcessCommand
+
+The main component is `ProcessCommand`. Which can configure and run a subprocess. The `read` and `run` methods are called on the `ProcessCommand`.
+
+```swift
+let command = ProcessCommand(
+    path: "/usr/bin/xcodebuild",
+    arguments: ["-version"]
+)
+try await command.run()
+```
+
+The location of the executable file is not always known. To do this, there is a `find` method that searches for an executable file by name.
+
+```swift
+try await ProcessCommand
+    .find("xcodebuild")!
+    .appending(argument: "-version")
+    .run()
 ```
 
 ## simctl
 
-Simulator control tool.
+By analogy with Shell, you can make other wrappers over the `ProcessCommand`
+
+`Simctl` (Simulator control tool) is an example of a complex such wrapper
 
-Fetch Extract the list of devices and filter them by the prefix of the name "iPhone".
+Using simctl, you can search for iPhone 12, turn it on and launch the application.
 
 ```swift
 let xcrun = XCRun()
-let simulator = try xcrun.simctl()
+let simulator = xcrun.simctl
+
+let list = try await simulator.list(.devices, "iPhone 12", available: true).json.decode()
+let devices = list.devices.flatMap { $0.value }
+
+for info in devices where info.state == "Booted" {
+    try await simulator.device(info.udid).shutdown.run()
+}
+            
+let udid =  devices.first!.udid
+try await simulator.device(udid).boot.run()
+try await simulator.device(udid).app("com.example.app").launch.run()
+```
 
-let devices = try simulator.list().devices(where: { device in
-    device.name.hasPrefix("iPhone")
-})
+## License
 
-devices
-```
+MIT

Playgrounds/README.playground/contents.xcplayground

@@ -0,0 +1,55 @@
+import Foundation
+
+extension Process {
+     var async: AsyncProcess {
+        AsyncProcess(process: self)
+    }
+}
+
+final class AsyncProcess {
+    private let _process: Process
+    private let _lock = NSLock()
+
+    fileprivate init(process: Process) {
+        self._process = process
+    }
+
+    /// Runs the process with the current environment.
+    func run() async throws {
+        try await withTaskCancellationHandler {
+            _terminate()
+        } operation: {
+            try Task.checkCancellation() // can be canceled before running
+            try await _run()
+        }
+    }
+
+    private func _run() async throws {
+        try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<Void, Error>) in
+            var runningError: Error?
+            _lock.lock()
+            _process.terminationHandler = { _ in
+                continuation.resume()
+            }
+            do {
+                try _process.run() // waiting for the `terminationHandler` call
+            } catch {
+                // `terminationHandler` is not called if if an error occurred
+                runningError = error
+            }
+            _lock.unlock()
+
+            if let runningError = runningError {
+                continuation.resume(throwing: runningError)
+            }
+        }
+    }
+
+    private func _terminate() {
+        _lock.lock()
+        if _process.isRunning { // can be canceled without starting
+            _process.terminate() // crash if not running
+        }
+        _lock.unlock()
+    }
+}

README.md

@@ -0,0 +1,28 @@
+import Foundation
+
+final class FileHandleReader {
+    fileprivate(set) var data = Data()
+
+    fileprivate init() {}
+}
+
+extension FileHandle {
+    func reader() -> FileHandleReader {
+        assert(self.readabilityHandler == nil)
+
+        let reader = FileHandleReader()
+
+        self.readabilityHandler = { fileHandle in
+            // invoke on serial queue
+            let data = fileHandle.availableData
+
+            if data.isEmpty {
+                // stop
+                fileHandle.readabilityHandler = nil
+            } else {
+                reader.data.append(data)
+            }
+        }
+        return reader
+    }
+}