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Fix link parsing to terminate properly #2091

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patriksvensson merged 2 commits into from
Apr 16, 2026
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Fix link parsing to terminate properly #2091

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baf4d95
Fix links being incorrectly merged into subsequent markup blocks.
zhuman Apr 16, 2026
6313989
Add tests around link markup rules, including specifically links embe…
zhuman Apr 16, 2026
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19 changes: 11 additions & 8 deletions src/Spectre.Console.Ansi/AnsiMarkup.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -54,7 +54,8 @@ public static IEnumerable<AnsiMarkupSegment> Parse(string markup, Style? style =
using var tokenizer = new MarkupTokenizer(markup);

var result = new List<AnsiMarkupSegment>();
var stack = new Stack<Style>();
var styleStack = new Stack<Style>();
var linkStack = new Stack<Link?>();
var link = default(Link?);

while (tokenizer.MoveNext())
Expand All @@ -64,25 +65,27 @@ public static IEnumerable<AnsiMarkupSegment> Parse(string markup, Style? style =
if (token.Kind == MarkupTokenKind.Open)
{
var parsed = AnsiMarkupTagParser.Parse(token.Value);
link ??= parsed.Link;
stack.Push(style.Value);
linkStack.Push(link);
link = parsed.Link ?? link;
styleStack.Push(style.Value);
style = style.Value.Combine(parsed.Style);
}
else if (token.Kind == MarkupTokenKind.Close)
{
if (stack.Count == 0)
if (styleStack.Count == 0)
{
throw new InvalidOperationException(
$"Encountered closing tag when none was expected near position {token.Position}.");
}

style = stack.Pop();
style = styleStack.Pop();
link = linkStack.Pop();
}
else if (token.Kind == MarkupTokenKind.Text)
{
if (result.Count > 0 && result[^1].Style.Equals(style))
if (result.Count > 0 && result[^1].Style.Equals(style) && Equals(result[^1].Link, link))
{
// Merge segments
// Merge segments with same style and link
result[^1].Text += token.Value;
}
else
Expand All @@ -98,7 +101,7 @@ public static IEnumerable<AnsiMarkupSegment> Parse(string markup, Style? style =
}
}

if (stack.Count > 0)
if (styleStack.Count > 0)
{
throw new InvalidOperationException("Unbalanced markup stack. Did you forget to close a tag?");
}
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36 changes: 36 additions & 0 deletions src/Spectre.Console.Tests/Unit/AnsiConsoleTests.Markup.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -223,5 +223,41 @@ public void Should_Preserve_Links_Over_Line_Breaks_When_Multiple_Segments_Are_Me
"\e]8;id=[0-9]*;https:\\/\\/example\\.com\\/readme.md\e\\\\Foo and \e]8;;\e\\\\\n" +
" \e]8;id=[0-9]*;https:\\/\\/example\\.com\\/readme.md\e\\\\Bar\e]8;;\e\\\\ ");
}

[Fact]
public void Should_Not_Apply_Link_To_Text_After_Link_Close_Tag()
{
// Given
var console = new TestConsole()
.EmitAnsiSequences();

// When - text after the [/] closing tag should NOT have the link
console.Markup("Before [link=https://example.com]LINK[/] After");

// Then
// The link should only wrap "LINK", not " After"
var output = console.Output;
output.ShouldMatch(@"Before \e\]8;id=\d+;https://example\.com\e\\LINK\e\]8;;\e\\ After");
}

[Fact]
public void Should_Properly_Handle_Nested_Link_With_Styles()
{
// Given
var console = new TestConsole()
.EmitAnsiSequences();

// When - link with styled text inside
console.Markup("[link=https://example.com][bold]Bold Link[/][/] Plain");

// Then
// The link should only wrap "Bold Link", not " Plain"
var output = console.Output;

// Check that "Plain" is NOT inside a link
var linkEndIndex = output.LastIndexOf("\u001b]8;;\u001b\\");
var plainIndex = output.IndexOf("Plain");
plainIndex.ShouldBeGreaterThan(linkEndIndex, "Plain should appear after the link ends");
}
}
}
215 changes: 215 additions & 0 deletions src/Spectre.Console.Tests/Unit/Prompts/SelectionPromptTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,221 @@ public sealed class SelectionPromptTests
{
private const string ESC = "\u001b";

[Fact]
public void Should_Not_Apply_Link_To_Text_After_Link_Close_Tag()
{
// Given
var console = new TestConsole()
.SupportsAnsi(true)
.EmitAnsiSequences();

// When - text after the [/] closing tag should NOT have the link
console.Markup("Before [link=https://example.com]LINK[/] After");

// Then
var output = console.Output;

// Link pattern: \e]8;id=xxx;url\e\\ text \e]8;;\e\\
// "Before " should not be in a link
// "LINK" should be in a link
// " After" should not be in a link

// The output should have exactly one link start and one link end
var linkStartRegex = new System.Text.RegularExpressions.Regex(@"\x1b\]8;id=\d+;[^\x1b]+\x1b\\");
var linkEndRegex = new System.Text.RegularExpressions.Regex(@"\x1b\]8;;\x1b\\");

var linkStarts = linkStartRegex.Matches(output);
var linkEnds = linkEndRegex.Matches(output);

linkStarts.Count.ShouldBe(1, $"Expected 1 link start. Output:\n{output.Replace(ESC, "\\e")}");
linkEnds.Count.ShouldBe(1, $"Expected 1 link end. Output:\n{output.Replace(ESC, "\\e")}");

// Verify " After" appears AFTER the link end
var linkEndIndex = linkEnds[0].Index;
var afterIndex = output.IndexOf(" After");

afterIndex.ShouldBeGreaterThan(linkEndIndex, $"' After' should appear after link end. Output:\n{output.Replace(ESC, "\\e")}");
}

[Fact]
public void Should_Properly_Close_Links_In_Selection_Items()
{
// Given
var console = new TestConsole();
console.Profile.Capabilities.Interactive = true;
console.Profile.Capabilities.Links = true;
console.EmitAnsiSequences();
// Navigate down to second item and then select it
console.Input.PushKey(ConsoleKey.DownArrow);
console.Input.PushKey(ConsoleKey.Enter);

// When
var prompt = new SelectionPrompt<string>()
.Title("Select one")
.AddChoices(
"[link=https://example.com]Link 1[/]",
"[link=https://example.org]Link 2[/]");
prompt.Show(console);

// Then
// Each link should be properly closed with the OSC 8 terminator (ESC]8;;ESC\)
// Count occurrences of link starts vs link ends
var output = console.Output;
var linkStartPattern = $"{ESC}]8;id=";
var linkEndPattern = $"{ESC}]8;;{ESC}\\";

var linkStarts = System.Text.RegularExpressions.Regex.Matches(output, System.Text.RegularExpressions.Regex.Escape(linkStartPattern)).Count;
var linkEnds = System.Text.RegularExpressions.Regex.Matches(output, System.Text.RegularExpressions.Regex.Escape(linkEndPattern)).Count;

// Every link start should have a corresponding link end
linkStarts.ShouldBe(linkEnds, $"Link starts ({linkStarts}) should equal link ends ({linkEnds}). Output:\n{output.Replace(ESC, "\\e")}");
}

[Fact]
public void Should_Close_Links_Before_Line_Clear_Operations()
{
// Given
var console = new TestConsole();
console.Profile.Capabilities.Interactive = true;
console.Profile.Capabilities.Links = true;
console.EmitAnsiSequences();
// Navigate down to second item and then select it
console.Input.PushKey(ConsoleKey.DownArrow);
console.Input.PushKey(ConsoleKey.Enter);

// When
var prompt = new SelectionPrompt<string>()
.Title("Select one")
.AddChoices(
"[link=https://example.com]Link 1[/]",
"[link=https://example.org]Link 2[/]");
prompt.Show(console);

// Then
// The output should never have a link start followed by erase-in-line (CSI K) without
// first closing the link. This pattern causes the link to "bleed" into erased content.
var output = console.Output;

// Pattern: link start ... erase-in-line without intervening link end
// Link start: ESC]8;id=...;url ESC\
// Erase in line: ESC[K or ESC[0K or ESC[1K or ESC[2K
// Link end: ESC]8;;ESC\
var linkStartRegex = new System.Text.RegularExpressions.Regex($@"\x1b\]8;id=\d+;[^\x1b]+\x1b\\");
var linkEndRegex = new System.Text.RegularExpressions.Regex($@"\x1b\]8;;\x1b\\");
var eraseInLineRegex = new System.Text.RegularExpressions.Regex($@"\x1b\[\d?K");

var allMatches = new List<(int Index, string Type, string Value)>();
foreach (System.Text.RegularExpressions.Match m in linkStartRegex.Matches(output))
{
allMatches.Add((m.Index, "START", m.Value));
}

foreach (System.Text.RegularExpressions.Match m in linkEndRegex.Matches(output))
{
allMatches.Add((m.Index, "END", m.Value));
}

foreach (System.Text.RegularExpressions.Match m in eraseInLineRegex.Matches(output))
{
allMatches.Add((m.Index, "ERASE", m.Value));
}

allMatches.Sort((a, b) => a.Index.CompareTo(b.Index));

// Check that no ERASE comes after START without END in between
var linkOpen = false;
foreach (var (index, type, value) in allMatches)
{
if (type == "START")
{
linkOpen = true;
}
else if (type == "END")
{
linkOpen = false;
}
else if (type == "ERASE" && linkOpen)
{
Assert.Fail($"Found erase-in-line operation while link was still open at index {index}. " +
$"This can cause links to 'bleed' into subsequent content.\n" +
$"Output (escaped): {output.Replace(ESC, "\\e")}");
}
}
}

[Fact]
public void Should_Terminate_Links_At_End_Of_Line()
{
// Given
var console = new TestConsole();
console.Profile.Capabilities.Interactive = true;
console.Profile.Capabilities.Links = true;
console.EmitAnsiSequences();
console.Input.PushKey(ConsoleKey.Enter);

// When
var prompt = new SelectionPrompt<string>()
.Title("Select one")
.AddChoices(
"[link=https://example.com]Link 1[/]",
"[link=https://example.org]Link 2[/]");
prompt.Show(console);

// Then
// Verify that links don't cross line boundaries - each line's link should be
// closed before the newline or before any cursor movement
var output = console.Output;

// Find all link sequences and line terminators
var linkStartRegex = new System.Text.RegularExpressions.Regex($@"\x1b\]8;id=\d+;[^\x1b]+\x1b\\");
var linkEndRegex = new System.Text.RegularExpressions.Regex($@"\x1b\]8;;\x1b\\");
var newlineRegex = new System.Text.RegularExpressions.Regex($@"\r?\n");
var cursorUpRegex = new System.Text.RegularExpressions.Regex($@"\x1b\[\d*A");

var allMatches = new List<(int Index, string Type, string Value)>();
foreach (System.Text.RegularExpressions.Match m in linkStartRegex.Matches(output))
{
allMatches.Add((m.Index, "START", m.Value));
}

foreach (System.Text.RegularExpressions.Match m in linkEndRegex.Matches(output))
{
allMatches.Add((m.Index, "END", m.Value));
}

foreach (System.Text.RegularExpressions.Match m in newlineRegex.Matches(output))
{
allMatches.Add((m.Index, "NEWLINE", m.Value));
}

foreach (System.Text.RegularExpressions.Match m in cursorUpRegex.Matches(output))
{
allMatches.Add((m.Index, "CURSOR_UP", m.Value));
}

allMatches.Sort((a, b) => a.Index.CompareTo(b.Index));

// Check that no NEWLINE or CURSOR_UP comes after START without END in between
var linkOpen = false;
foreach (var (index, type, value) in allMatches)
{
if (type == "START")
{
linkOpen = true;
}
else if (type == "END")
{
linkOpen = false;
}
else if ((type == "NEWLINE" || type == "CURSOR_UP") && linkOpen)
{
Assert.Fail($"Found {type} while link was still open at index {index}. " +
$"Links should be closed before line/cursor changes.\n" +
$"Output (escaped): {output.Replace(ESC, "\\e")}");
}
}
}

[Fact]
public void Should_Not_Throw_When_Selecting_An_Item_With_Escaped_Markup()
{
Expand Down