Merge pull request #111 from orchetect/dev

`.send(events:)`: Improved reliability of sending SysEx

Sources/MIDIKit/IO/Core MIDI/MIDIPacketLIst/MIDIPacketList Utilities.swift

@@ -74,6 +74,7 @@ extension UnsafeMutablePointer where Pointee == MIDIPacketList {
     /// Assembles an array of `Byte` arrays into Core MIDI `MIDIPacket`s and wraps them in a `MIDIPacketList`.
     ///
     /// - Note: You must deallocate the pointer when finished with it.
+    /// - Note: System Exclusive messages must each be packed in a dedicated MIDIPacketList with no other events, otherwise MIDIPacketList may fail.
     @inline(__always)
     internal init(data: [[MIDI.Byte]]) throws {
 

Sources/MIDIKit/IO/Managed/Protocols/MIDIIOSendsMIDIMessagesProtocol.swift

@@ -152,7 +152,14 @@ extension _MIDIIOSendsMIDIMessagesProtocol {
 
         switch api {
         case .legacyCoreMIDI:
-            try send(rawMessages: events.map { $0.midi1RawBytes })
+            if events.contains(where: { $0.isSystemExclusive }) {
+                // System Exclusive events must be the only event in a MIDIPacketList
+                // so force each event to be sent in its own packet
+                try events.forEach { try send(event: $0) }
+            } else {
+                // combine events into a single MIDIPacketList
+                try send(rawMessages: events.map { $0.midi1RawBytes })
+            }
 
         case .newCoreMIDI:
             guard #available(macOS 11, iOS 14, macCatalyst 14, tvOS 14, watchOS 7, *) else {
@@ -172,4 +179,3 @@ extension _MIDIIOSendsMIDIMessagesProtocol {
     }
 
 }
-

Tests/MIDIKitTests/Integration Tests/Round Trip Tests.swift

@@ -262,8 +262,10 @@ open class RoundTrip_Tests_Base: XCTestCase {
 
         receivedEvents.reserveCapacity(sourceEvents.count)
 
-        for event in sourceEvents {
-            try output.send(event: event)
+        // send several events at once to test packing
+        // multiple packets into a single MIDIPacketList / MIDIEventList
+        for eventGroup in sourceEvents.split(every: 2) {
+            try output.send(events: Array(eventGroup))
         }
 
         wait(sec: 0.5)

Tests/MIDIKitTests/Tests Helpers.swift

@@ -0,0 +1,53 @@
+/// ------------------------------------------------------------------------------------
+/// ------------------------------------------------------------------------------------
+/// Borrowed from [OTCore 1.4.1](https://github.com/orchetect/OTCore) under MIT license.
+/// Methods herein are unit tested in OTCore, so no unit tests are necessary in MIDIKit.
+/// ------------------------------------------------------------------------------------
+/// ------------------------------------------------------------------------------------
+
+#if shouldTestCurrentPlatform
+
+import Foundation
+
+extension Collection {
+
+    /// **OTCore:**
+    /// Splits a `Collection` or `String` into groups of `length` characters, grouping from left-to-right. If `backwards` is true, right-to-left.
+    @_disfavoredOverload
+    internal func split(every: Int,
+                        backwards: Bool = false) -> [SubSequence] {
+
+        var result: [SubSequence] = []
+
+        for i in stride(from: 0, to: count, by: every) {
+
+            switch backwards {
+            case true:
+                let offsetEndIndex = index(endIndex, offsetBy: -i)
+                let offsetStartIndex = index(offsetEndIndex,
+                                             offsetBy: -every,
+                                             limitedBy: startIndex)
+                ?? startIndex
+
+                result.insert(self[offsetStartIndex..<offsetEndIndex], at: 0)
+
+            case false:
+                let offsetStartIndex = index(startIndex, offsetBy: i)
+                let offsetEndIndex = index(offsetStartIndex,
+                                           offsetBy: every,
+                                           limitedBy: endIndex)
+                ?? endIndex
+
+                result.append(self[offsetStartIndex..<offsetEndIndex])
+
+            }
+
+        }
+
+        return result
+
+    }
+
+}
+
+#endif