Allow Longer Rows In Stream Mode

Use a larger buffer in stream mode since the json can't be
pretty-printed before parsing by gron, and therefore may have long
lines.

main.go

@@ -227,6 +227,8 @@ func gronStream(r io.Reader, w io.Writer, opts int) (int, error) {
 
 	// Read the input line by line
 	sc := bufio.NewScanner(r)
+	buf := make([]byte, 0, 64*1024)
+	sc.Buffer(buf, 1024*1024)
 	i := 0
 	for sc.Scan() {
 

main_test.go

@@ -88,6 +88,44 @@ func TestGronStream(t *testing.T) {
 
 }
 
+func TestLargeGronStream(t *testing.T) {
+	cases := []struct {
+		inFile  string
+		outFile string
+	}{
+		{"testdata/long-stream.json", "testdata/long-stream.gron"},
+	}
+
+	for _, c := range cases {
+		in, err := os.Open(c.inFile)
+		if err != nil {
+			t.Fatalf("failed to open input file: %s", err)
+		}
+
+		want, err := ioutil.ReadFile(c.outFile)
+		if err != nil {
+			t.Fatalf("failed to open want file: %s", err)
+		}
+
+		out := &bytes.Buffer{}
+		code, err := gronStream(in, out, optMonochrome)
+
+		if code != exitOK {
+			t.Errorf("want exitOK; have %d", code)
+		}
+		if err != nil {
+			t.Errorf("want nil error; have %s", err)
+		}
+
+		if !reflect.DeepEqual(want, out.Bytes()) {
+			t.Logf("want: %s", want)
+			t.Logf("have: %s", out.Bytes())
+			t.Errorf("gronned %s does not match %s", c.inFile, c.outFile)
+		}
+	}
+
+}
+
 func TestUngron(t *testing.T) {
 	cases := []struct {
 		inFile  string