Improve Discord markdown escaper. Fixes #14

formatter_test.go

@@ -0,0 +1,57 @@
+// mautrix-discord - A Matrix-Discord puppeting bridge.
+// Copyright (C) 2022 Tulir Asokan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestEscapeDiscordMarkdown(t *testing.T) {
+	type escapeTest struct {
+		name     string
+		input    string
+		expected string
+	}
+
+	tests := []escapeTest{
+		{"Simple text", "Lorem ipsum dolor sit amet, consectetuer adipiscing elit.", "Lorem ipsum dolor sit amet, consectetuer adipiscing elit."},
+		{"Backslash", `foo\bar`, `foo\\bar`},
+		{"Underscore", `foo_bar`, `foo\_bar`},
+		{"Asterisk", `foo*bar`, `foo\*bar`},
+		{"Tilde", `foo~bar`, `foo\~bar`},
+		{"Backtick", "foo`bar", "foo\\`bar"},
+		{"Forward tick", `foo´bar`, `foo´bar`},
+		{"Pipe", `foo|bar`, `foo\|bar`},
+		{"Less than", `foo<bar`, `foo\<bar`},
+		{"Greater than", `foo>bar`, `foo>bar`},
+		{"Multiple things", `\_*~|`, `\\\_\*\~\|`},
+		{"URL", `https://example.com/foo_bar`, `https://example.com/foo_bar`},
+		{"Multiple URLs", `hello_world https://example.com/foo_bar *testing* https://a_b_c/*def*`, `hello\_world https://example.com/foo_bar \*testing\* https://a_b_c/*def*`},
+		{"URL ends with no-break zero-width space", "https://example.com\ufefffoo_bar", "https://example.com\ufefffoo\\_bar"},
+		{"URL ends with less than", `https://example.com<foo_bar`, `https://example.com<foo\_bar`},
+		{"Short URL", `https://_`, `https://_`},
+		{"Insecure URL", `http://example.com/foo_bar`, `http://example.com/foo_bar`},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			assert.Equal(t, test.expected, escapeDiscordMarkdown(test.input))
+		})
+	}
+}