Created Escape function on markdown package

[BUG] #3664

[BUG] Escaping specific markdown in
commit messages on Discord-type embeds #3664

Reformatted into a table driven test

Moved function escapeMarkdown to Discord webhooks;
Moved compile regex to outside function;
Using refactored eplacements for multiple values;
Using assertions from testify.

Fixed formatting

Moved string new replacer to outside function

services/webhook/discord.go

@@ -10,6 +10,7 @@ import (
 	"html/template"
 	"net/http"
 	"net/url"
+	"regexp"
 	"strconv"
 	"strings"
 	"unicode/utf8"
@@ -202,6 +203,9 @@ func (d discordConvertor) Push(p *api.PushPayload) (DiscordPayload, error) {
 		// limit the commit message display to just the summary, otherwise it would be hard to read
 		message := strings.TrimRight(strings.SplitN(commit.Message, "\n", 1)[0], "\r")
 
+		// Escaping markdown character
+		message = escapeMarkdown(message)
+
 		// a limit of 50 is set because GitHub does the same
 		if utf8.RuneCountInString(message) > 50 {
 			message = fmt.Sprintf("%.47s...", message)
@@ -365,3 +369,40 @@ func (d discordConvertor) createPayload(s *api.User, title, text, url string, co
 		},
 	}
 }
+
+var orderedListPattern = regexp.MustCompile(`(\d+)\.`)
+
+var markdownPatterns = map[string]*regexp.Regexp{
+	"~": regexp.MustCompile(`\~(.*?)\~`),
+	"*": regexp.MustCompile(`\*(.*?)\*`),
+	"_": regexp.MustCompile(`\_(.*?)\_`),
+}
+
+var markdownToEscape = strings.NewReplacer(
+	"* ", "\\* ",
+	"`", "\\`",
+	"[", "\\[",
+	"]", "\\]",
+	"(", "\\(",
+	")", "\\)",
+	"#", "\\#",
+	"+ ", "\\+ ",
+	"- ", "\\- ",
+	"---", "\\---",
+	"!", "\\!",
+	"|", "\\|",
+	"<", "\\<",
+	">", "\\>",
+)
+
+// Escape Markdown characters
+func escapeMarkdown(input string) string {
+	// Escaping ordered list
+	output := orderedListPattern.ReplaceAllString(input, "$1\\.")
+
+	for char, pattern := range markdownPatterns {
+		output = pattern.ReplaceAllString(output, fmt.Sprintf(`\%s$1\%s`, char, char))
+	}
+
+	return markdownToEscape.Replace(output)
+}

services/webhook/discord_test.go

@@ -94,6 +94,20 @@ func TestDiscordPayload(t *testing.T) {
 		assert.Equal(t, p.Sender.AvatarURL, pl.Embeds[0].Author.IconURL)
 	})
 
+	t.Run("PushWithMarkdownCharactersInCommitMessage", func(t *testing.T) {
+		p := pushTestEscapeCommitMessagePayload()
+
+		pl, err := dc.Push(p)
+		require.NoError(t, err)
+
+		assert.Len(t, pl.Embeds, 1)
+		assert.Equal(t, "[test/repo:test] 2 new commits", pl.Embeds[0].Title)
+		assert.Equal(t, "[2020558](http://localhost:3000/test/repo/commit/2020558fe2e34debb818a514715839cabd25e778) \\# conflicts\n\\# \\- some/conflicting/file.txt - user1\n[2020558](http://localhost:3000/test/repo/commit/2020558fe2e34debb818a514715839cabd25e778) \\# conflicts\n\\# \\- some/conflicting/file.txt - user1", pl.Embeds[0].Description)
+		assert.Equal(t, p.Sender.UserName, pl.Embeds[0].Author.Name)
+		assert.Equal(t, setting.AppURL+p.Sender.UserName, pl.Embeds[0].Author.URL)
+		assert.Equal(t, p.Sender.AvatarURL, pl.Embeds[0].Author.IconURL)
+	})
+
 	t.Run("Issue", func(t *testing.T) {
 		p := issueTestPayload()
 
@@ -346,3 +360,89 @@ func TestDiscordJSONPayload(t *testing.T) {
 	require.NoError(t, err)
 	assert.Equal(t, "[2020558](http://localhost:3000/test/repo/commit/2020558fe2e34debb818a514715839cabd25e778) commit message - user1\n[2020558](http://localhost:3000/test/repo/commit/2020558fe2e34debb818a514715839cabd25e778) commit message - user1", body.Embeds[0].Description)
 }
+
+var escapedMarkdownTests = map[string]struct {
+	input    string
+	expected string
+}{
+	"Escape heading level 1": {
+		input:    "# Heading level 1",
+		expected: "\\# Heading level 1",
+	},
+	"Escape heading level 2": {
+		input:    "## Heading level 2",
+		expected: "\\#\\# Heading level 2",
+	},
+	"Escape heading level 3": {
+		input:    "### Heading level 3",
+		expected: "\\#\\#\\# Heading level 3",
+	},
+	"Escape bold text": {
+		input:    "**bold text**",
+		expected: "\\*\\*bold text\\*\\*",
+	},
+	"Escape italic text": {
+		input:    "*italic text*",
+		expected: "\\*italic text\\*",
+	},
+	"Escape italic text underline": {
+		input:    "_italic text_",
+		expected: "\\_italic text\\_",
+	},
+	"Escape strikethrough": {
+		input:    "~~strikethrough~~",
+		expected: "\\~\\~strikethrough\\~\\~",
+	},
+	"Escape Ordered list item": {
+		input:    "1. Ordered list item\n2. Second ordered list item\n999999999999. 999999999999 ordered list item",
+		expected: "1\\. Ordered list item\n2\\. Second ordered list item\n999999999999\\. 999999999999 ordered list item",
+	},
+	"Escape Unordered list item": {
+		input:    "- Unordered list\n + using plus",
+		expected: "\\- Unordered list\n \\+ using plus",
+	},
+	"Escape bullet list item": {
+		input:    "* Bullet list item",
+		expected: "\\* Bullet list item",
+	},
+	"Escape table": {
+		input:    "| Table | Example |\n|-|-|\n| Lorem | Ipsum |",
+		expected: "\\| Table \\| Example \\|\n\\|-\\|-\\|\n\\| Lorem \\| Ipsum \\|",
+	},
+	"Escape link": {
+		input:    "[Link to Forgejo](https://forgejo.org/)",
+		expected: "\\[Link to Forgejo\\]\\(https://forgejo.org/\\)",
+	},
+	"Escape Alt text for an image": {
+		input:    "![Alt text for an image](https://forgejo.org/_astro/mascot-dark.1omhhgvT_Zm0N2n.webp)",
+		expected: "\\!\\[Alt text for an image\\]\\(https://forgejo.org/\\_astro/mascot-dark.1omhhgvT\\_Zm0N2n.webp\\)",
+	},
+	"Escape URL if it has markdown character": {
+		input:    "https://forgejo.org/_astro/mascot-dark.1omhhgvT_Zm0N2n.webp",
+		expected: "https://forgejo.org/\\_astro/mascot-dark.1omhhgvT\\_Zm0N2n.webp",
+	},
+	"Escape blockquote text": {
+		input:    "> Blockquote text.",
+		expected: "\\> Blockquote text.",
+	},
+	"Escape inline code": {
+		input:    "`Inline code`",
+		expected: "\\`Inline code\\`",
+	},
+	"Escape multiple code": {
+		input:    "```\nCode block\nwith multiple lines\n```\n",
+		expected: "\\`\\`\\`\nCode block\nwith multiple lines\n\\`\\`\\`\n",
+	},
+	"Escape horizontal rule": {
+		input:    "---",
+		expected: "\\---",
+	},
+}
+
+func TestEscapeMarkdownChar(t *testing.T) {
+	for name, test := range escapedMarkdownTests {
+		t.Run(name, func(t *testing.T) {
+			assert.Equal(t, test.expected, escapeMarkdown(test.input))
+		})
+	}
+}

services/webhook/general_test.go

@@ -72,6 +72,10 @@ func pushTestMultilineCommitMessagePayload() *api.PushPayload {
 	return pushTestPayloadWithCommitMessage("This is a commit summary ⚠️⚠️⚠️⚠️ containing 你好 ⚠️⚠️️\n\nThis is the message body.")
 }
 
+func pushTestEscapeCommitMessagePayload() *api.PushPayload {
+	return pushTestPayloadWithCommitMessage("# conflicts\n# - some/conflicting/file.txt")
+}
+
 func pushTestPayloadWithCommitMessage(message string) *api.PushPayload {
 	commit := &api.PayloadCommit{
 		ID:      "2020558fe2e34debb818a514715839cabd25e778",