neiam /gitgud

defmodule GitGud.LanguagesTest do
  use ExUnit.Case, async: true

  alias GitGud.Languages

  test "detects by extension, case-insensitive" do
    assert Languages.detect("foo.ex") == "Elixir"
    assert Languages.detect("Foo.EX") == "Elixir"
    assert Languages.detect("a/b/c.rs") == "Rust"
  end

  test "detects by well-known basename" do
    assert Languages.detect("Dockerfile") == "Dockerfile"
    assert Languages.detect("makefile") == "Makefile"
    assert Languages.detect("mix.exs") == "Elixir"
  end

  test "nil for unknown filenames + nil input" do
    assert Languages.detect("LICENSE") == nil
    assert Languages.detect("README") == nil
    assert Languages.detect("img.png") == nil
    assert Languages.detect(nil) == nil
  end

  test "basename match wins over extension lookup" do
    # mix.exs would also match the .exs extension, but the basename rule
    # is consulted first — both happen to be "Elixir" here, which is
    # the right answer either way. The point is the lookup terminates
    # on basename without re-checking ext.
    assert Languages.detect("path/to/mix.exs") == "Elixir"
  end
end