Add tests for local uuid and os.clock

To get execution coverage of bc.lua to 100%, add two more tests:

1. The first one ensures that os.clock is used properly when
   computer.uptime() is not available.
2. The second one tests the fallback implementation of uuid generation
   when uuid.next() is not available.

tests/run.lua

@@ -13,6 +13,7 @@ test_sources = {
   "tests/local.lua",
   "tests/network.lua",
   "tests/timeout.lua",
+  "tests/misc.lua",
 }
 for _, source in ipairs(test_sources) do
   loadfile("./tests/"..source)()

tests/tests/misc.lua

@@ -0,0 +1,59 @@
+local test = require("u-test")
+
+local serialization = require("serialization")
+local computer = require("computer")
+local uuid = require("uuid")
+
+local computer_uptime_saved
+function test.os_clock.start_up()
+  computer_uptime_saved = computer.uptime
+  computer.uptime = nil
+end
+function test.os_clock.tear_down()
+  computer.uptime = computer_uptime_saved
+  -- Force reload of the module
+  package.loaded.bc = nil
+  local BaseControl = require("bc")
+end
+
+function test.os_clock.test_monkeypatched()
+  -- Force reload of the module
+  package.loaded.bc = nil
+  local BaseControl = require("bc")
+
+  -- Test a timeout to prove it works
+  local bc1 = BaseControl:new()
+  test.error_raised(function()
+    bc1:finalize({"to_final1"}, 0.1)
+  end, "timeout")
+end
+
+local uuid_next_saved
+function test.uuid.start_up()
+  uuid_next_saved = uuid.next
+  uuid.next = nil
+end
+function test.uuid.tear_down()
+  uuid.next = uuid_next_saved
+  -- Force reload of the module
+  package.loaded.bc = nil
+  local BaseControl = require("bc")
+end
+
+function test.uuid.test_monkeypatched()
+  -- Force reload of the module
+  package.loaded.bc = nil
+  local BaseControl = require("bc")
+
+  -- Test a listener as this will use a uuid
+  local bc = BaseControl:new()
+  bc:register("lisuuid1", 1234)
+  bc:finalize()
+
+  local id1 = bc:listen(
+    "lisuuid1", bc.Query.Change, function(new) end)
+  local id2 = bc:listen(
+    "lisuuid1", bc.Query.Change, function(new) end)
+
+  test.not_equal(id1, id2, "uuid collision")
+end