package media_test import ( "io" "testing" "git.netflux.io/rob/clipper/media" "github.com/stretchr/testify/assert" ) type testReader struct { count int data [][]byte } func (r *testReader) Read(p []byte) (int, error) { if r.count == len(r.data) { return 0, io.EOF } n := copy(p, r.data[r.count]) r.count++ return n, nil } func TestModuloBufReader(t *testing.T) { reader := testReader{ data: [][]byte{ {'a', 'b', 'c', 'd'}, {'e', 'f', 'g', 'h', 'i'}, {}, {'j', 'k', 'l', 'm'}, {'n', 'o', 'p'}, {'q', 'r', 's', 't', 'u'}, }, } modReader := media.NewModuloBufReader(io.NopCloser(&reader), 4) out := make([]byte, 5) n, err := modReader.Read(out) assert.NoError(t, err) assert.Equal(t, 4, n) assert.Equal(t, []byte{'a', 'b', 'c', 'd'}, out[:n]) n, err = modReader.Read(out) assert.NoError(t, err) assert.Equal(t, 4, n) assert.Equal(t, []byte{'e', 'f', 'g', 'h'}, out[:n]) n, err = modReader.Read(out) assert.NoError(t, err) assert.Zero(t, n) assert.Empty(t, out[:n]) n, err = modReader.Read(out) assert.NoError(t, err) assert.NoError(t, err) assert.Equal(t, 4, n) assert.Equal(t, []byte{'i', 'j', 'k', 'l'}, out[:n]) n, err = modReader.Read(out) assert.NoError(t, err) assert.Equal(t, 4, n) assert.Equal(t, []byte{'m', 'n', 'o', 'p'}, out[:n]) n, err = modReader.Read(out) assert.NoError(t, err) assert.Equal(t, 4, n) assert.Equal(t, []byte{'q', 'r', 's', 't'}, out[:n]) n, err = modReader.Read(out) assert.Equal(t, io.EOF, err) assert.Equal(t, 1, n) assert.Equal(t, []byte{'u'}, out[:n]) n, err = modReader.Read(out) assert.Zero(t, n) assert.Equal(t, io.EOF, err) }