diff options
| -rw-r--r-- | skate/map.go | 21 | ||||
| -rw-r--r-- | skate/map_test.go | 40 |
2 files changed, 56 insertions, 5 deletions
diff --git a/skate/map.go b/skate/map.go index 9d3c98d..094d3e2 100644 --- a/skate/map.go +++ b/skate/map.go @@ -40,14 +40,25 @@ type PartialDoc struct { // doc). We want fields, but we do not want to bake in TSV into each function. type Mapper func([]byte) ([][]byte, error) -// AsTSV serializes the result of a field mapper as TSV. This is a slim adapter, -// e.g. to parallel.Processor, which expects this function signature. +// AsTSV serializes the result of a field mapper as TSV. This is a slim +// adapter, e.g. to parallel.Processor, which expects this function signature. +// If the last byte of the last field is not a newline, it will be appended. func (f Mapper) AsTSV(p []byte) ([]byte, error) { - fields, err := f(p) - if err != nil { + var ( + fields [][]byte + err error + ) + if fields, err = f(p); err != nil { return nil, err } - return bytes.Join(fields, bTab), nil + if len(fields) == 0 { + return nil, nil + } + b := bytes.Join(fields, bTab) + if len(b) > 0 && !bytes.HasSuffix(b, bNewline) { + b = append(b, bNewline...) + } + return b, nil } // WithPrefix adds a given prefix to the first element. diff --git a/skate/map_test.go b/skate/map_test.go index a439d33..a81cb3d 100644 --- a/skate/map_test.go +++ b/skate/map_test.go @@ -149,6 +149,46 @@ func TestMapperTitleSandcrawler(t *testing.T) { } } +func TestAsTSV(t *testing.T) { + var cases = []struct { + f Mapper + err error + want string + }{ + { + f: Mapper(func(_ []byte) ([][]byte, error) { + return [][]byte{ + []byte("a"), + []byte("b"), + []byte("c"), + }, nil + }), + err: nil, + want: "a\tb\tc\n", + }, + { + f: Mapper(func(_ []byte) ([][]byte, error) { + return [][]byte{ + []byte("a"), + []byte("b"), + []byte("c\n"), + }, nil + }), + err: nil, + want: "a\tb\tc\n", + }, + } + for _, c := range cases { + got, err := c.f.AsTSV([]byte{}) + if err != c.err { + t.Fatalf("got %v, want nil", got) + } + if string(got) != c.want { + t.Fatalf("got %v, want %v", string(got), c.want) + } + } +} + func prettySlice(p [][]byte) (result []string) { result = make([]string, len(p)) for i, v := range p { |