tests: some stuff

- added basic GetPlaybackRate tests
- adjusted SetPlaybackRate tests

Author: FirstLemon

gluatests/lua/tests/modules/bass/igmodaudiochannel/GetPlaybackRate.lua

@@ -0,0 +1,41 @@
+return {
+    groupName = "IGModAudioChannel:GetPlaybackRate",
+
+    cases = {
+        {
+            name = "Function exists when module enabled",
+            when = HolyLib_IsModuleEnabled( "bass" ),
+            func = function()
+                expect( FindMetaTable( "IGModAudioChannel" ).GetPlaybackRate ).to.beA( "function" )
+            end
+        },
+        {
+            name = "Function is nil when module disabled",
+            when = not HolyLib_IsModuleEnabled( "bass" ),
+            func = function()
+                expect( bass ).to.beA( "nil" )
+            end
+        },
+        {
+            name = "Valid call sets the playback rate correctly",
+            when = HolyLib_IsModuleEnabled( "bass" ),
+            async = true,
+            timeout = 2,
+            func = function()
+                local filePath = "sound/bass_testsound.wav"
+                local flags = ""
+        
+                bass.PlayFile( filePath, flags, function( channel, errorCode, errorMsg )
+                    expect( channel ).to.beValid()
+                    expect( errorCode ).to.equal( 0 )
+                    expect( errorMsg ).to.beNil()
+
+                    channel:SetPlaybackRate( 2 )
+                    expect( channel:GetPlaybackRate() ).to.equal( 2 )
+
+                    done()
+                end )
+            end
+        },
+    }
+}

gluatests/lua/tests/modules/bass/igmodaudiochannel/SetPlaybackrate.lua

@@ -37,24 +37,5 @@ return {
                 end )
             end
         },
-        {
-            name = "SetPlaybackRate works after pausing or stopping the channel",
-            when = HolyLib_IsModuleEnabled("bass"),
-            async = true,
-            func = function()
-                local filePath = "sound/bass_testsound.wav"
-                local flags = ""
-
-                bass.PlayFile(filePath, flags, function( channel )
-                    channel:Pause()
-                    expect( channel:SetPlaybackRate, 1 ).toNot.err()
-
-                    channel:Stop()
-                    expect( channel:SetPlaybackRate, 1.2 ).to.err()
-
-                    done()
-                end )
-            end
-        }
     }
 }