A simple fast platform switcher for Unity

UnityPlatformSwitcher.cs

using UnityEngine;
using UnityEditor;
using System.Collections;
using System.IO;

public class PlatformSwitcher
{
	[MenuItem("Platform/PC, Mac and Linux Standalone")]
	static void SwitchPlatformToDesktop()
	{
		SwitchTo(BuildTarget.StandaloneOSXIntel);
	}

	[MenuItem("Platform/PC, Mac and Linux Standalone", true)]
	static bool SwitchPlatformToDesktopValidate()
	{
		return EditorUserBuildSettings.activeBuildTarget != BuildTarget.StandaloneOSXIntel;
	}

	[MenuItem("Platform/iOS")]
	static void SwitchPlatformToIOS()
	{
		SwitchTo(BuildTarget.iPhone);
	}

	[MenuItem("Platform/iOS", true)]
	static bool SwitchPlatformToIOSValidate()
	{
		return EditorUserBuildSettings.activeBuildTarget != BuildTarget.iPhone;
	}

	[MenuItem("Platform/Android")]
	static void SwitchPlatformToAndroid()
	{
		SwitchTo(BuildTarget.Android);
	}

	[MenuItem("Platform/Android", true)]
	static bool SwitchPlatformToAndroidValidate()
	{
		return EditorUserBuildSettings.activeBuildTarget != BuildTarget.Android;
	}

	public static void SwitchTo(BuildTarget targetPlatform)
	{
		var currentPlatform = EditorUserBuildSettings.activeBuildTarget;
		if (currentPlatform == targetPlatform)
			return;

		// Don't switch when compiling
		if (EditorApplication.isCompiling)
		{
			Debug.LogWarning("Could not switch platform because unity is compiling");
			return;
		}

		// Don't switch while playing
		if (EditorApplication.isPlayingOrWillChangePlaymode)
		{
			Debug.LogWarning("Could not switch platform because unity is in playMode");
			return;
		}

		Debug.Log("Switching platform from " + currentPlatform + " to " + targetPlatform);

		string libDir = "Library";
		string libDirCurrent = libDir + "_" + currentPlatform;
		string libDirTarget = libDir + "_" + targetPlatform;

		// If target dir doesn't exist yet, make a copy of the current one
		if (!Directory.Exists(libDirTarget))
		{
			Debug.Log("Making a copy of " + libDir + " because " + libDirTarget + " doesn't exist yet");
			CopyFilesRecursively(new DirectoryInfo(libDir), new DirectoryInfo(libDirTarget));
		}

		// Safety check, libDirCurrent shouldn't exist (current data is stored in libDir)
		if (Directory.Exists(libDirCurrent))
			Directory.Delete(libDirCurrent, true);

		// Rename dirs
		Directory.Move(libDir, libDirCurrent);
		Directory.Move(libDirTarget, libDir);

		EditorUserBuildSettings.SwitchActiveBuildTarget(targetPlatform);
		Debug.Log("Platform switched to " + targetPlatform);
	}


	public static void CopyFilesRecursively(DirectoryInfo source, DirectoryInfo target)
	{
		foreach (DirectoryInfo dir in source.GetDirectories())
			CopyFilesRecursively(dir, target.CreateSubdirectory(dir.Name));

		foreach (FileInfo file in source.GetFiles())
			file.CopyTo(Path.Combine(target.FullName, file.Name));
	}
}

@andreiagmu Thanks! I have to download 2019.3 then.