test: Port app platform detection to Busted

spec/app_spec.lua

@@ -13,3 +13,15 @@ describe("pl.app.lua", function ()
   end)
 
 end)
+
+describe("pl.app.platform", function ()
+
+  -- TODO: Find a reliable alternate way to determine platform to check that
+  -- this is returning the right answer, not just any old answer.
+  it("should at least return a valid platform", function ()
+    local platforms = { Linux = true, OSX = true, Windows = true }
+    local detected = app.platform()
+    assert.is.truthy(platforms[detected])
+  end)
+
+end)

tests/test-app.lua

@@ -260,4 +260,3 @@ do -- app.parse_args
     asserteq(s, {})
 
 end
-

tests/test-date.lua

@@ -119,6 +119,3 @@ asserteq(tostring(nxt - d), '1 month ')
 --- Can explicitly get UTC date; these of course refer to same time
 local now,utc  = Date(), Date 'utc'
 asserteq(tostring(now - utc),'zero')
-
-if app.platform() ~= 'Windows' then
-end