snapshot of https://github.com/mattermost/mattermost.git (master, 2026-09-16; blobs > 131072B omitted)

server/public/shared/markdown/markdown_test.go

@@ -0,0 +1,63 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package markdown
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestParse(t *testing.T) {
+	t.Run("rejects input longer than maxLen bytes without parsing it", func(t *testing.T) {
+		markdown := strings.Repeat("a", MaxLen()+1)
+		document, referenceDefinitions := Parse(markdown)
+		assert.Empty(t, document.Children)
+		assert.Empty(t, referenceDefinitions)
+	})
+
+	t.Run("SetMaxPostSize raises the cap so a previously rejected input is parsed", func(t *testing.T) {
+		SetMaxPostRunes(defaultMaxPostRunes)
+		defer SetMaxPostRunes(defaultMaxPostRunes)
+
+		markdown := strings.Repeat("a", MaxLen()+1)
+
+		document, _ := Parse(markdown)
+		assert.Empty(t, document.Children)
+
+		SetMaxPostRunes(defaultMaxPostRunes + 1)
+
+		document, _ = Parse(markdown)
+		assert.NotEmpty(t, document.Children)
+
+		SetMaxPostRunes(defaultMaxPostRunes)
+	})
+
+	t.Run("nesting depth is bounded regardless of how deeply a single line nests", func(t *testing.T) {
+		// Without the depth cap in blockStart/blockQuoteStart/listStart, this would force parse
+		// work that grows with the nesting depth rather than staying bounded.
+		n := 20000
+		markdown := strings.Repeat("> ", n) + "x"
+
+		document, _ := Parse(markdown)
+		require.Len(t, document.Children, 1)
+
+		depth := 0
+		block := document.Children[0]
+		for {
+			blockQuote, ok := block.(*BlockQuote)
+			if !ok {
+				break
+			}
+			depth++
+			require.NotEmpty(t, blockQuote.Children)
+			block = blockQuote.Children[0]
+		}
+		// ParseBlocks counts the Document itself as the first ancestor, so a full parse tops out
+		// one level below the maxNestingDepth threshold used by the block-start functions directly.
+		assert.Equal(t, maxNestingDepth-1, depth)
+	})
+}