return fmt.Errorf("worker: tested something other than target: %s", line)
		}
		if strings.TrimPrefix(line, "FuzzA ") != `"seed"` {
			sawAMutant = true
		}
	}
	if err := scan.Err(); err != nil && err != bufio.ErrTooLong {
		return err
	}
	if !sawAMutant {
		return fmt.Errorf("worker: did not test any mutants")
	}
	return nil
}
-- mutator_test.go --
package fuzz_test

import (
	"testing"
)

	n, err = r.Read(b)
	if err != nil {
		t.Fatalf("expected nil: %d / %v", n, err)
	}
	r = NewDocumentDecoder(io.NopCloser(bytes.NewReader([]byte(dd))))
	b = make([]byte, maxLen)
	n, err = r.Read(b)
	if err != bufio.ErrTooLong {
		t.Fatalf("bufio.Scanner: token too long: %d / %v", n, err)
	}
}

func TestYAMLDecoderCallsAfterErrShortBufferRestOfFrame(t *testing.T) {
	d := `---
stuff: 1
	test-foo: 1`

		{"ErrBufferFull", Var, 0},
		{"ErrFinalToken", Var, 6},
		{"ErrInvalidUnreadByte", Var, 0},
		{"ErrInvalidUnreadRune", Var, 0},
		{"ErrNegativeAdvance", Var, 1},
		{"ErrNegativeCount", Var, 0},
		{"ErrTooLong", Var, 1},
		{"MaxScanTokenSize", Const, 1},
		{"NewReadWriter", Func, 0},
		{"NewReader", Func, 0},
		{"NewReaderSize", Func, 0},
		{"NewScanner", Func, 1},
		{"NewWriter", Func, 0},

pkg bufio, type Scanner struct
pkg bufio, type SplitFunc func([]uint8, bool) (int, []uint8, error)
pkg bufio, var ErrAdvanceTooFar error
pkg bufio, var ErrNegativeAdvance error
pkg bufio, var ErrTooLong error
pkg bytes, const MinRead = 512
pkg bytes, func TrimPrefix([]uint8, []uint8) []uint8
pkg bytes, func TrimSuffix([]uint8, []uint8) []uint8
pkg bytes, method (*Buffer) Grow(int)