decoding: catch bad tabs

decode/bug_test.go

@@ -1,6 +1,7 @@
 package decode_test
 
 import (
+	"errors"
 	"testing"
 
 	"github.com/ionous/tell/collect/imap"
@@ -33,3 +34,12 @@ func TestBug(t *testing.T) {
   - "other"`,
 	)
 }
+
+// verify that an erroneous tab is caught
+func TestTabCatching(t *testing.T) {
+	var badTab = "- - \"First\"\n\t- \"Second\""
+	test(t,
+		"bad tab",
+		errors.New("tabs are invalid"),
+		badTab)
+}

token/tokens.go

@@ -76,6 +76,8 @@ func (n *tokenizer) tokenize() charm.State {
 	return charm.Statement("tokenize", func(q rune) (ret charm.State) {
 		n.start = n.curr
 		switch q {
+		case runes.HTab:
+			ret = charm.Error(errors.New("tabs are invalid whitespace"))
 		case runes.Hash:
 			next := n.commentDecoder()
 			ret = send(next, q)