package aghio import ( "fmt" "io" "io/ioutil" "strings" "testing" "github.com/stretchr/testify/assert" ) func TestLimitReadCloser(t *testing.T) { testCases := []struct { name string n int64 want error }{{ name: "positive", n: 1, want: nil, }, { name: "zero", n: 0, want: nil, }, { name: "negative", n: -1, want: fmt.Errorf("aghio: invalid n in LimitReadCloser: -1"), }} for _, tc := range testCases { t.Run(tc.name, func(t *testing.T) { _, err := LimitReadCloser(nil, tc.n) assert.Equal(t, tc.want, err) }) } } func TestLimitedReadCloser_Read(t *testing.T) { testCases := []struct { name string limit int64 rStr string want int err error }{{ name: "perfectly_match", limit: 3, rStr: "abc", want: 3, err: nil, }, { name: "eof", limit: 3, rStr: "", want: 0, err: io.EOF, }, { name: "limit_reached", limit: 0, rStr: "abc", want: 0, err: &LimitReachedError{ Limit: 0, }, }, { name: "truncated", limit: 2, rStr: "abc", want: 2, err: nil, }} for _, tc := range testCases { t.Run(tc.name, func(t *testing.T) { readCloser := ioutil.NopCloser(strings.NewReader(tc.rStr)) buf := make([]byte, tc.limit+1) lreader, err := LimitReadCloser(readCloser, tc.limit) assert.Nil(t, err) n, err := lreader.Read(buf) assert.Equal(t, n, tc.want) assert.Equal(t, tc.err, err) }) } } func TestLimitedReadCloser_LimitReachedError(t *testing.T) { testCases := []struct { name string want string err error }{{ name: "simplest", want: "attempted to read more than 0 bytes", err: &LimitReachedError{ Limit: 0, }, }} for _, tc := range testCases { t.Run(tc.name, func(t *testing.T) { assert.Equal(t, tc.want, tc.err.Error()) }) } }