added some tests, fixed some wrong behaviours

spec/arguments_spec.lua

@@ -0,0 +1,164 @@
+local largparse = require "largparse"
+
+describe("tests related to positional arguments", function()
+   local function curry(f, ...)
+      local args = {...}
+      return function() return f(table.unpack(args)) end
+   end
+
+   describe("passing correct arguments", function()
+      it("handles empty parser correctly", function()
+         local parser = largparse.parser()
+         local args = parser:parse({})
+         assert.same(args, {})
+      end)
+
+      it("handles one argument correctly", function()
+         local parser = largparse.parser()
+         parser:argument "foo"
+         local args = parser:parse({"bar"})
+         assert.same(args, {foo = "bar"})
+      end)
+
+      it("handles several arguments correctly", function()
+         local parser = largparse.parser()
+         parser:argument "foo1"
+         parser:argument "foo2"
+         local args = parser:parse({"bar", "baz"})
+         assert.same(args, {foo1 = "bar", foo2 = "baz"})
+      end)
+
+      it("handles multi-argument correctly", function()
+         local parser = largparse.parser()
+         parser:argument("foo", {
+            args = "*"
+         })
+         local args = parser:parse({"bar", "baz", "qu"})
+         assert.same(args, {foo = {"bar", "baz", "qu"}})
+      end)
+
+      it("handles restrained multi-argument correctly", function()
+         local parser = largparse.parser()
+         parser:argument("foo", {
+            args = "2-4"
+         })
+         local args = parser:parse({"bar", "baz"})
+         assert.same(args, {foo = {"bar", "baz"}})
+      end)
+
+      it("handles several multi-arguments correctly", function()
+         local parser = largparse.parser()
+         parser:argument("foo1", {
+            args = "1-2"
+         })
+         parser:argument("foo2", {
+            args = "*"
+         })
+         local args = parser:parse({"bar"})
+         assert.same(args, {foo1 = {"bar"}, foo2 = {}})
+         args = parser:parse({"bar", "baz", "qu"})
+         assert.same(args, {foo1 = {"bar", "baz"}, foo2 = {"qu"}})
+      end)
+   end)
+
+   describe("passing incorrect arguments", function()
+      local old_parser = largparse.parser
+
+      setup(function()
+         largparse.parser = old_parser:extends()
+         function largparse.parser:error(fmt, ...)
+            error(fmt:format(...))
+         end
+      end)
+
+
+      it("handles extra arguments with empty parser correctly", function()
+         local parser = largparse.parser()
+
+         assert.has_error(curry(parser.parse, parser, {"foo"}), "too many arguments")
+      end)
+
+      it("handles extra arguments with one argument correctly", function()
+         local parser = largparse.parser()
+         parser:argument "foo"
+
+         assert.has_error(curry(parser.parse, parser, {"bar", "baz"}), "too many arguments")
+      end)
+
+      it("handles sudden option correctly", function()
+         local parser = largparse.parser()
+         parser:argument "foo"
+
+         assert.has_error(curry(parser.parse, parser, {"-q"}), "unknown option -q")
+      end)
+
+      it("handles too few arguments with one argument correctly", function()
+         local parser = largparse.parser()
+         parser:argument "foo"
+
+         assert.has_error(curry(parser.parse, parser, {}), "too few arguments")
+      end)
+
+      it("handles extra arguments with several arguments correctly", function()
+         local parser = largparse.parser()
+         parser:argument "foo1"
+         parser:argument "foo2"
+
+         assert.has_error(curry(parser.parse, parser, {"bar", "baz", "qu"}), "too many arguments")
+      end)
+
+      it("handles too few arguments with several arguments correctly", function()
+         local parser = largparse.parser()
+         parser:argument "foo1"
+         parser:argument "foo2"
+
+         assert.has_error(curry(parser.parse, parser, {"bar"}), "too few arguments")
+      end)
+
+      it("handles too few arguments with multi-argument correctly", function()
+         local parser = largparse.parser()
+         parser:argument("foo", {
+            args = "+"
+         })
+         assert.has_error(curry(parser.parse, parser, {}), "too few arguments")
+      end)
+
+      it("handles too many arguments with multi-argument correctly", function()
+         local parser = largparse.parser()
+         parser:argument("foo", {
+            args = "2-4"
+         })
+         assert.has_error(curry(parser.parse, parser, {"foo", "bar", "baz", "qu", "quu"}), "too many arguments")
+      end)
+
+      it("handles too few arguments with multi-argument correctly", function()
+         local parser = largparse.parser()
+         parser:argument("foo", {
+            args = "2-4"
+         })
+         assert.has_error(curry(parser.parse, parser, {"foo"}), "too few arguments")
+      end)
+
+      it("handles too many arguments with several multi-arguments correctly", function()
+         local parser = largparse.parser()
+         parser:argument("foo1", {
+            args = "1-2"
+         })
+         parser:argument("foo2", {
+            args = "0-1"
+         })
+         assert.has_error(curry(parser.parse, parser, {"foo", "bar", "baz", "qu"}), "too many arguments")
+      end)
+
+      it("handles too few arguments with several multi-arguments correctly", function()
+         local parser = largparse.parser()
+         parser:argument("foo1", {
+            args = "1-2"
+         })
+         parser:argument("foo2", {
+            args = "*"
+         })
+         assert.has_error(curry(parser.parse, parser, {}), "too few arguments")
+      end)
+   end)
+end)