change CleanText to return not more symbols than provided max

app/main.go

@@ -158,7 +158,7 @@ func makeTwitter(opts options) *proc.TwitterClient {
 			// template failed to parse record, backup predefined format
 			return fmt.Sprintf("%s - %s", item.Title, item.Link)
 		}
-		return strings.Replace(proc.CleanText(b1.String(), 275), `\n`, "\n", -1) // \n in template
+		return strings.Replace(proc.CleanText(b1.String(), 280), `\n`, "\n", -1) // \n in template
 	}
 
 	twiAuth := proc.TwitterAuth{

app/proc/twitter.go

@@ -47,11 +47,12 @@ func (t *TwitterClient) Send(item feed.Item) error {
 	return nil
 }
 
-// CleanText removes html tags and shrinks result, adding 4 symbols on top
+// CleanText removes html tags and shrinks result
 func CleanText(inp string, max int) string {
 	res := striphtmltags.StripTags(inp)
 	if len([]rune(res)) > max {
-		snippet := []rune(res)[:max]
+		// 4 symbols reserved for space and three dots on the end
+		snippet := []rune(res)[:max-4]
 		// go back in snippet and found first space
 		for i := len(snippet) - 1; i >= 0; i-- {
 			if snippet[i] == ' ' {

app/proc/twitter_test.go

@@ -63,9 +63,9 @@ func TestCleanText(t *testing.T) {
 		max      int
 	}{
 		{"test", "test", 10},
-		{"test 12345 aaaa", "test ...", 6},
-		{"<b>test 12345 aaaa</b>", "test ...", 6},
-		{"<b>test12345 aaaa</b>", "test12 ...", 6},
+		{"test 12345 aaaa", "test ...", 10},
+		{"<b>test 12345 aaaa</b>", "test ...", 10},
+		{"<b>test12345 aaaa</b>", "test12 ...", 10},
 	}
 
 	for i, tt := range tbl {