Tests for Timer.sleep().

src/module/timer.c

@@ -11,6 +11,8 @@
 static const char* timerLibSource =
 "class Timer {\n"
 "  static sleep(milliseconds) {\n"
+"    if (!(milliseconds is Num)) Fiber.abort(\"Milliseconds must be a number.\")\n"
+"    if (milliseconds < 0) Fiber.abort(\"Milliseconds cannot be negative.\")\n"
 "    startTimer_(milliseconds, Fiber.current)\n"
 "    Fiber.yield()\n"
 "  }\n"

src/module/timer.h

@@ -3,7 +3,6 @@
 
 #include "wren.h"
 
-// TODO: Coherent naming scheme.
 char* timerGetSource();
 
 WrenForeignMethodFn timerBindForeign(

src/module/timer.wren

@@ -1,5 +1,7 @@
 class Timer {
   static sleep(milliseconds) {
+    if (!(milliseconds is Num)) Fiber.abort("Milliseconds must be a number.")
+    if (milliseconds < 0) Fiber.abort("Milliseconds cannot be negative.")
     startTimer_(milliseconds, Fiber.current)
     Fiber.yield()
   }