package atomictemp

import (
  "errors"
  "io"
  "os"
  "path/filepath"
  "testing"
)

func TestCreate(t *testing.T) {
  dir, err := os.MkdirTemp("", "")
  if err != nil {
    t.Error(err)
  }

  // test good file
  goodTests := []string { "foo", "bar", "baz" }
  for _, test := range(goodTests) {
    t.Run(test, func(t *testing.T) {
      // build destination path
      path := filepath.Join(dir, test)

      // create temp file
      err := Create(path, func(f io.Writer) error {
        _, err := f.Write([]byte(test))
        return err
      })

      if err != nil {
        t.Error(err)
        return
      }

      if got, err := os.ReadFile(path); err != nil {
        t.Error(err)
      } else if string(got) != test {
        t.Errorf("got \"%s\", exp \"%s\"", string(got), test)
      }
    })
  }

  t.Run("badDir", func(t *testing.T) {
    // build nonsense path to destination file
    badPath := filepath.Join(dir, "does/not/exist")

    err := Create(badPath, func(_ io.Writer) error {
      return nil
    })

    if err == nil {
      t.Errorf("got success, exp error")
    }
  })

  t.Run("badFunc", func(t *testing.T) {
    // build path
    path := filepath.Join(dir, "badFunc")

    err := Create(path, func(_ io.Writer) error {
      return errors.New("ack!")
    })

    if err == nil {
      t.Errorf("got success, exp error")
    }
  })
}