Function TestReaderDiscard

pkg/bufio/bufio_test.go:733–860

(t *testing.T)

}

func TestReaderDiscard(t *testing.T) {
	tests := []struct {
		name     string
		r        io.Reader
		bufSize  int // 0 means 16
		peekSize int

		n int // input to Discard

		want    int   // from Discard
		wantErr error // from Discard

		wantBuffered int
	}{
		{
			name:         "normal case",
			r:            strings.NewReader("abcdefghijklmnopqrstuvwxyz"),
			peekSize:     16,
			n:            6,
			want:         6,
			wantBuffered: 10,
		},
		{
			name:         "discard causing read",
			r:            strings.NewReader("abcdefghijklmnopqrstuvwxyz"),
			n:            6,
			want:         6,
			wantBuffered: 10,
		},
		{
			name:         "discard all without peek",
			r:            strings.NewReader("abcdefghijklmnopqrstuvwxyz"),
			n:            26,
			want:         26,
			wantBuffered: 0,
		},
		{
			name:         "discard more than end",
			r:            strings.NewReader("abcdefghijklmnopqrstuvwxyz"),
			n:            27,
			want:         26,
			wantErr:      io.EOF,
			wantBuffered: 0,
		},
		// Any error from filling shouldn't show up until we
		// get past the valid bytes. Here we return we return 5 valid bytes at the same time
		// as an error, but test that we don't see the error from Discard.
		{
			name: "fill error, discard less",
			r: newScriptedReader(func(p []byte) (n int, err error) {
				if len(p) < 5 {
					panic("unexpected small read")
				}
				return 5, errors.New("5-then-error")
			}),
			n:            4,
			want:         4,
			wantErr:      nil,