fix bug, test

src/PortAudio.jl

@@ -48,6 +48,7 @@ using .LibPortAudio:
     Pa_Initialize,
     paInputOverflowed,
     Pa_IsStreamStopped,
+    paNoDevice,
     paNoFlag,
     Pa_OpenStream,
     paOutputUnderflowed,
@@ -195,12 +196,22 @@ function show(io::IO, device::PortAudioDevice)
     print(io, device.output_bounds.max_channels)
 end
 
+function check_device_exists(device_index, device_type)
+    if device_index == paNoDevice
+        throw(ArgumentError("No $device_type device available"))
+    end
+end
+
 function get_default_input_index()
-    handle_status(Pa_GetDefaultInputDevice())
+    device_index = Pa_GetDefaultInputDevice()
+    check_device_exists(device_index, "input")
+    device_index
 end
 
 function get_default_output_index()
-    handle_status(Pa_GetDefaultOutputDevice())
+    device_index = Pa_GetDefaultOutputDevice()
+    check_device_exists(device_index, "output")
+    device_index
 end
 
 # we can look up devices by index or name

test/runtests.jl

@@ -11,6 +11,7 @@ using PortAudio:
     get_output_type,
     handle_status,
     initialize,
+    name,
     PortAudioException,
     PortAudio,
     PortAudioDevice,
@@ -18,7 +19,7 @@ using PortAudio:
     safe_load,
     seek_alsa_conf,
     terminate,
-    name
+    write_buffer
 using PortAudio.LibPortAudio:
     Pa_AbortStream,
     PaError,
@@ -109,7 +110,9 @@ using Test: @test, @test_logs, @test_nowarn, @testset, @test_throws
     initialize()
 end
 
-if !isempty(devices())
+if isempty(devices())
+    @test_throws ArgumentError("No input device available") get_default_input_index()
+else
     @testset "Tests with sound" begin
         # these default values are specific to local machines
         input_name = get_device(get_default_input_index()).name
@@ -130,6 +133,7 @@ if !isempty(devices())
             sleep(1)
             println("Testing pass-through")
             stream = PortAudioStream(input_name, output_name, 2, 2; adjust_channels = true)
+            write_buffer(stream.sink_messenger.buffer, acquire_lock = false)
             sink = stream.sink
             source = stream.source
             @test sprint(show, stream) == """