argparse/spec/usage_spec.lua

local argparse = require "argparse"

describe("tests related to usage message generation", function()
   it("creates correct usage message for empty parser", function()
      local parser = argparse.parser "foo"
      assert.equal(parser:prepare():get_usage(), "Usage: foo")
   end)

   it("creates correct usage message for arguments", function()
      local parser = argparse.parser "foo"
      parser:argument "first"
      parser:argument "second-and-third" {
         args = 2
      }
      parser:argument "maybe-fourth" {
         args = "?"
      }
      parser:argument "others" {
         args = "*"
      }
      assert.equal(
         [=[Usage: foo <first> <second-and-third> <second-and-third> [<maybe-fourth>] [<others>] ...]=],
         parser:prepare():get_usage()
      )
   end)

   it("creates correct usage message for options", function()
      local parser = argparse.parser "foo"
      parser:flag "-q" "--quiet"
      parser:option "--from" {
         count = 1,
         target = "server"
      }
      parser:option "--config"
      assert.equal(
         [=[Usage: foo [-q] --from <server> [--config <config>]]=],
         parser:prepare():get_usage()
      )
   end)

   it("creates correct usage message for commands", function()
      local parser = argparse.parser "foo"
      parser:flag "-q" "--quiet"
      local run = parser:command "run"
      run:option "--where"
      assert.equal(
         [=[Usage: foo [-q] [<command>] ...]=],
         parser:prepare():get_usage()
      )
   end)

   describe("usage generation can be customized", function()
      it("uses message provided by user", function()
         local parser = argparse.parser "foo" {
            usage = "Usage: obvious"
         }
         parser:flag "-q" "--quiet"
         assert.equal(
            [=[Usage: obvious]=],
            parser:prepare():get_usage()
         )
      end)

      it("uses per-option message provided by user", function()
         local parser = argparse.parser "foo"
         parser:flag "-q" "--quiet" {
            usage = "[-q | --quiet]"
         }
         assert.equal(
            [=[Usage: foo [-q | --quiet]]=],
            parser:prepare():get_usage()
         )
      end)

      it("uses argnames provided by user", function()
         local parser = argparse.parser "foo"
         parser:argument "inputs" {
            args = "1-2",
            argname = "<input>"
         }
         assert.equal(
            [=[Usage: foo <input> [<input>]]=],
            parser:prepare():get_usage()
         )
      end)
   end)
end)