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⚡ Bolt: [Performance optimization] WslPathResolver allocation reduction #144

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⚡ Bolt: [Performance optimization] WslPathResolver allocation reduction #144

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⚡ Bolt: [Performance optimization] Avoid string array and string allo…
google-labs-jules[bot] Jul 31, 2026
598759b
fix: apply CodeRabbit auto-fixes
coderabbitai[bot] Jul 31, 2026
c1e8a80
⚡ Bolt: [Performance optimization] Avoid string array and string allo…
google-labs-jules[bot] Jul 31, 2026
ca30e4d
Merge branch 'master' into bolt-wslpathresolver-split-106113106063795…
tonythethompson Jul 31, 2026
e7bf692
Potential fix for pull request finding
tonythethompson Jul 31, 2026
421b1b2
⚡ Bolt: [Performance optimization] Avoid string array and string allo…
google-labs-jules[bot] Jul 31, 2026
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3 changes: 3 additions & 0 deletions .jules/bolt.md
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Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
## 2024-05-24 - WslPathResolver string splitting
**Learning:** `WslPathResolver.TryParseUncRemainder` used `string.Split()`, `string.Join()`, and `Enumerable.Skip()` which leads to unnecessary GC pressure and multiple string/array allocations for hot path code.
**Action:** Replace `string.Split` with `ReadOnlySpan<char>.Split` and use `StringBuilder` to append portions sequentially when parsing and reconstructing path parts. This saves multiple array/string allocations and makes parsing faster.
Comment on lines +1 to +3

@coderabbitai coderabbitai Bot Jul 31, 2026

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📐 Maintainability & Code Quality | 🟡 Minor | ⚡ Quick win

Fix the Markdown heading structure.

markdownlint reports MD041 because the file starts with an h2 heading. It also reports MD022 because the heading has no blank line after it. Change the first heading to h1 and add a blank line.

Proposed fix 
-## 2024-05-24 - WslPathResolver string splitting
+# 2024-05-24 - WslPathResolver string splitting
+
 **Learning:** `WslPathResolver.TryParseUncRemainder` used `string.Split()`, `string.Join()`, and `Enumerable.Skip()` which leads to unnecessary GC pressure and multiple string/array allocations for hot path code.
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
## 2024-05-24 - WslPathResolver string splitting
**Learning:** `WslPathResolver.TryParseUncRemainder` used `string.Split()`, `string.Join()`, and `Enumerable.Skip()` which leads to unnecessary GC pressure and multiple string/array allocations for hot path code.
**Action:** Replace `string.Split` with `ReadOnlySpan<char>.Split` and use `StringBuilder` to append portions sequentially when parsing and reconstructing path parts. This saves multiple array/string allocations and makes parsing faster.
# 2024-05-24 - WslPathResolver string splitting
**Learning:** `WslPathResolver.TryParseUncRemainder` used `string.Split()`, `string.Join()`, and `Enumerable.Skip()` which leads to unnecessary GC pressure and multiple string/array allocations for hot path code.
**Action:** Replace `string.Split` with `ReadOnlySpan<char>.Split` and use `StringBuilder` to append portions sequentially when parsing and reconstructing path parts. This saves multiple array/string allocations and makes parsing faster.
🧰 Tools
🪛 LanguageTool

[style] ~3-~3: Consider using a different verb to strengthen your wording.
Context: ...s multiple array/string allocations and makes parsing faster.

(MAKE_XXX_FASTER)

🪛 markdownlint-cli2 (0.23.1)

[warning] 1-1: Headings should be surrounded by blank lines
Expected: 1; Actual: 0; Below

(MD022, blanks-around-headings)

[warning] 1-1: First line in a file should be a top-level heading

(MD041, first-line-heading, first-line-h1)

🤖 Prompt for AI Agents 
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In @.jules/bolt.md around lines 1 - 3, Update the first heading in the
WslPathResolver learning entry from h2 to h1, then add a blank line immediately
after it so the document satisfies MD041 and MD022.

Source: Linters/SAST tools

31 changes: 27 additions & 4 deletions QuickShell.Core/Services/WslPathResolver.cs
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Expand Up @@ -142,16 +142,39 @@
private static bool TryParseUncRemainder(string remainder, string fullUnc, out WslLocation location)
{
location = null!;
var parts = remainder.Split('\\', StringSplitOptions.RemoveEmptyEntries);
if (parts.Length < 2)
// Bolt: Performance optimization - avoid string.Split(), Linq Skip(), and string.Join() allocations.
var span = remainder.AsSpan();
string? distro = null;
var linuxPathBuilder = new System.Text.StringBuilder(span.Length);

foreach (var range in span.Split('\\'))
{
var part = span[range];
if (part.IsEmpty)
{
continue;
}

if (distro is null)
{
distro = part.ToString();
}
else
{
linuxPathBuilder.Append('/');
linuxPathBuilder.Append(part);
}
}

if (linuxPathBuilder.Length == 0 || distro is null)
{
return false;
}

location = new WslLocation
{
Distro = parts[0],
LinuxPath = "/" + string.Join('/', parts.Skip(1)),
Distro = distro,
LinuxPath = linuxPathBuilder.ToString(),
Comment on lines +150 to +177

@coderabbitai coderabbitai Bot Jul 31, 2026

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📐 Maintainability & Code Quality | 🔵 Trivial | ⚡ Quick win

Add direct tests for UNC remainder parsing.

WslPathResolverTests.cs does not directly exercise this parser. Add cases for both \\wsl$\ and \\wsl.localhost\, repeated separators, trailing separators, a missing distro, and a missing Linux path. Assert Distro, LinuxPath, UncPath, and rejected inputs. This protects the span iteration and validation contract.

🧰 Tools
🪛 GitHub Check: CodeQL

[warning] 150-150: Useless assignment to local variable
This assignment to range is useless, since its value is never read.

🤖 Prompt for AI Agents 
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@QuickShell.Core/Services/WslPathResolver.cs` around lines 150 - 177, Add
direct tests in WslPathResolverTests for UNC remainder parsing, covering both
\\wsl$\ and \\wsl.localhost\ prefixes, repeated and trailing separators, missing
distro, and missing Linux path. Assert the resulting Distro, LinuxPath, and
UncPath values for valid inputs, and verify invalid inputs are rejected,
targeting the parser behavior implemented around the span iteration and
validation checks.

Source: MCP tools

UncPath = fullUnc,
};

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