Change basename to splitfilename, return extension

spec/nextfile_spec.lua

@@ -1,16 +1,18 @@
-describe("basename", function()
+describe("splitfilename", function()
 	local nextfile = require "nextfile"
 
-	it("should return the basename of an absolute filepath", function()
+	it("should return the filename and extension of an absolute filepath", function()
-		local name = nextfile.basename("/testdir/701.txt")
+		local name, ext = nextfile.splitfilename("/testdir/701.txt")
 
 		assert.are.equal("701", name)
+		assert.are.equal("txt", ext)
 	end)
 
-	it("should return the basename of a relative filepath", function()
+	it("should return the filename and extension of a relative filepath", function()
-		local name = nextfile.basename("../../foo/testdir/file.mp3")
+		local name, ext = nextfile.splitfilename("../../foo/testdir/file.mp3")
 
 		assert.are.equal("file", name)
+		assert.are.equal("mp3", ext)
 	end)
 end)
 
@@ -37,13 +39,13 @@ describe("nextfile", function()
 		end)
 	end)
 
---	insulate("prevfile.prevfile returns a numeric filename", function()
+	--insulate("prevfile.prevfile returns a numeric filename", function()
---		prevfile.prevfile = function() return "/testdir/701.txt" end
+		--prevfile.prevfile = function() return "/testdir/701.txt" end
 --
---		it("should return the result of incrementing the filename", function()
+		--it("should return the result of incrementing the filename", function()
---			local file = nextfile.nextfile("/testdir")
+			--local file = nextfile.nextfile("/testdir")
 --
---			assert.are.equal("/testdir/702.txt", file)
+			--assert.are.equal("/testdir/702.txt", file)
---		end)
+		--end)
---	end)
+	--end)
 end)

src/nextfile.lua

@@ -2,14 +2,18 @@ local prevfile = require "prevfile"
 
 local nextfile = {}
 
-function nextfile.basename(path)
+function nextfile.splitfilename(path)
-	return path:match("^.*/(.*)%.%w*")
+	name, ext = path:match("^.*/(.*)%.(%w*)")
-
+	return name, ext
 end
 
 function nextfile.nextfile(directory)
-	prevfile.prevfile(directory)
+	local previous = prevfile.prevfile(directory)
-	return nil
+	if previous == nil then return nil end
+
+	local name, ext = nextfile.splitfilename(previous)
+	
+	return ""
 end
 
 return nextfile