{not json}
no newline`
	const want = `unexpected text
{"Package":"abc:variant"}
more text
{"Package":"abc:variant"}trailing text
{not json}
no newline`
	checkJSONFilter(t, in, want)
}

func TestJSONFilterBoundaries(t *testing.T) {
	const in = `{"Package":"abc"}
{"Package":"def"}
{"Package":"ghi"}
`
	want := strings.ReplaceAll(in, `"}`, `:variant"}`)

	// Write one bytes at a time.