Add --wrap option and 'toggle-wrap' action (#3887)

* `--wrap`
* `--wrap-sign`
* `toggle-wrap`

Close #3619
Close #2236
Close #577
Close #461

src/util/chars_test.go

@@ -1,6 +1,9 @@
 package util
 
-import "testing"
+import (
+	"fmt"
+	"testing"
+)
 
 func TestToCharsAscii(t *testing.T) {
 	chars := ToChars([]byte("foobar"))
@@ -44,3 +47,37 @@ func TestTrimLength(t *testing.T) {
 	check("  h   o  ", 5)
 	check("         ", 0)
 }
+
+func TestCharsLines(t *testing.T) {
+	chars := ToChars([]byte("abcdef\n가나다\n\tdef"))
+	check := func(multiLine bool, maxLines int, wrapCols int, wrapSignWidth int, tabstop int, expectedNumLines int, expectedOverflow bool) {
+		lines, overflow := chars.Lines(multiLine, maxLines, wrapCols, wrapSignWidth, tabstop)
+		fmt.Println(lines, overflow)
+		if len(lines) != expectedNumLines || overflow != expectedOverflow {
+			t.Errorf("Invalid result: %d %v (expected %d %v)", len(lines), overflow, expectedNumLines, expectedOverflow)
+		}
+	}
+
+	// No wrap
+	check(true, 1, 0, 0, 8, 1, true)
+	check(true, 2, 0, 0, 8, 2, true)
+	check(true, 3, 0, 0, 8, 3, false)
+
+	// Wrap (2)
+	check(true, 4, 2, 0, 8, 4, true)
+	check(true, 5, 2, 0, 8, 5, true)
+	check(true, 6, 2, 0, 8, 6, true)
+	check(true, 7, 2, 0, 8, 7, true)
+	check(true, 8, 2, 0, 8, 8, true)
+	check(true, 9, 2, 0, 8, 9, false)
+	check(true, 9, 2, 0, 1, 8, false) // Smaller tab size
+
+	// With wrap sign (3 + 1)
+	check(true, 100, 3, 1, 1, 8, false)
+
+	// With wrap sign (3 + 2)
+	check(true, 100, 3, 2, 1, 12, false)
+
+	// With wrap sign (3 + 2) and no multi-line
+	check(false, 100, 3, 2, 1, 13, false)
+}