Add wrapLines function

sboehler · Nov 21, 2024 · 48d7454 · 48d7454
1 parent 26c30f0
commit 48d7454
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Showing 2 changed files with 69 additions and 0 deletions.
diff --git a/lib/syntax/printer/printer.go b/lib/syntax/printer/printer.go
@@ -194,3 +194,28 @@ func (p *Printer) Format(f directives.File) error {
 	_, err := p.Write([]byte(text[pos:]))
 	return err
 }
+
+func wrapLines(width int, text string) []string {
+	fields := strings.Fields(text)
+	var res []string
+	var b strings.Builder
+
+	for len(fields) > 0 {
+		lineLength := utf8.RuneCountInString(fields[0])
+		b.WriteString(fields[0])
+		fields = fields[1:]
+		for len(fields) > 0 {
+			fieldLength := utf8.RuneCountInString(fields[0])
+			if lineLength+fieldLength+1 > width {
+				break
+			}
+			lineLength += 1 + utf8.RuneCountInString(fields[0])
+			b.WriteRune(' ')
+			b.WriteString(fields[0])
+			fields = fields[1:]
+		}
+		res = append(res, b.String())
+		b.Reset()
+	}
+	return res
+}
diff --git a/lib/syntax/printer/printer_test.go b/lib/syntax/printer/printer_test.go
@@ -265,3 +265,47 @@ func TestFormat(t *testing.T) {
 func lines(ss ...string) string {
 	return strings.Join(ss, "\n") + "\n"
 }
+
+func TestWrapLines(t *testing.T) {
+	tests := []struct {
+		width int
+		input string
+		want  []string
+	}{
+		{
+			width: 5,
+			input: "foo   bar baz",
+			want:  []string{"foo", "bar", "baz"},
+		},
+		{
+			width: 5,
+			input: "foo   barbarbar baz",
+			want:  []string{"foo", "barbarbar", "baz"},
+		},
+		{
+			width: 7,
+			input: "foo   bar baz",
+			want:  []string{"foo bar", "baz"},
+		},
+		{
+			width: 11,
+			input: "foo   bar baz",
+			want:  []string{"foo bar baz"},
+		},
+		{
+			width: 5,
+			input: "      ",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.input, func(t *testing.T) {
+
+			got := wrapLines(test.width, test.input)
+
+			if diff := cmp.Diff(test.want, got); diff != "" {
+				t.Fatalf("wrapLines(%d, %s) returned unexpected diff (-want/+got)\n%s", test.width, test.input, diff)
+			}
+		})
+	}
+}