fix(checkver): Prevent variable values from carrying over between iterations

[z-Fng]

Description

Motivation and Context

Closes

• [Bug] Incorrect Version Returned Due to Uninitialized Variable in Checkver #6425

When running checkver.ps1 for multiple apps, if the checkver is script and throws, it may return an incorrect version due to variables leakage from the previous iteration.

Changes

This PR makes the following changes:

• fix(checkver): Prevent variable values from carrying over between iterations.

Testcase

$testcases = @(
    @{
        app   = "QTCreater"
        url   = "https://www.qt.io/offline-installers"
        regex = "Qt Creator\s+([\d.]+)\s+for Windows"
    }
    @{
        app    = "QQ"
        script = @(
            "`$url = 'https://im.qq.com/pcqq/index.shtml'",
            "`$resp = Invoke-WebRequest -Uri `$url",
            "`$cont = `$resp.Content",
            "`$pattern = 'https://qq-web.cdn-go.cn.*windowsDownloadUrl.js'",
            "`$jsUrl = [regex]::Match(`$cont, `$pattern).Value",
            "Invoke-WebRequest -Uri `$jsUrl"
        )
        regex  = "PCQQ([\d\.]+)/QQ([\d\.]+).exe"
    }
)

foreach ($testcase in $testcases) {
    $app = $testcase.app
    $re = New-Object System.Text.RegularExpressions.Regex($testcase.regex)

    # Prevent variable leakage from previous iteration
    # $page, $match = $null

    Write-Host "$app | ErrorActionPreference: $ErrorActionPreference"

    if ($testcase.script) {
        $page = Invoke-Command ([scriptblock]::Create($script -join "`r`n"))

        Write-Host "$app | Using script, page length $($page.Length)"
    } else {        
        $page = (Invoke-WebRequest -Uri $testcase.url -UseBasicParsing).Content

        Write-Host "$app | Using URL, page length $($page.Length)"
    }

    $match = $re.Matches($page) | Select-Object -First 1

    Write-Host "$app | Found: $match `r`n"
}

Checklist:

• I have read the Contributing Guide.
• I have ensured that I am targeting the develop branch.
• I have updated the documentation accordingly.
• I have updated the tests accordingly.
• I have added an entry in the CHANGELOG.

Summary by CodeRabbit

• Bug Fixes

  • Prevented intermittent cross-iteration leakage during asynchronous checks that could cause incorrect parsing or version detection; each iteration now processes results independently for more reliable multi-URL operations.

• Chores

  • Minor internal cleanup and clarifying comment to reduce stale state risk; no user-facing behavior or configuration changes.

[coderabbitai]

Walkthrough

Resets per-iteration state variables ($page, $match, and $matchesHashtable) to $null in bin/checkver.ps1’s asynchronous download loop immediately after assigning $ver from $Version; adds a descriptive comment. No control-flow, error-handling, or API/signature changes.

Changes

Cohort / File(s)	Summary of Changes
Async loop state cleanup bin/checkver.ps1	Added explicit resets of $page, $match, and $matchesHashtable to $null within the async download loop (performed immediately after assigning $ver from $Version) and added a descriptive comment. No control-flow or API changes.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

I’m a rabbit in the loop, I hop and I clear,
Wiping old traces so each run is near;
Page and matches vanish, tidy and bright,
Fresh parsing awaits with each new byte. 🐇✨

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changes. Docstring coverage check skipped.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title Check	✅ Passed	The title succinctly identifies the primary change—preventing variable leakage in checkver—and directly matches the PR description and code summary (resetting $page, $match, and $matchesHashtable in bin/checkver.ps1). It is specific, concise, and clear for a reviewer scanning history.

✨ Finishing touches

• 📝 Generate Docstrings

🧪 Generate unit tests

• Create PR with unit tests
• Post copyable unit tests in a comment

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[coderabbitai]

Actionable comments posted: 1

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 04b7ce7 and 795673a.

📒 Files selected for processing (1)

• bin/checkver.ps1 (1 hunks)

🔇 Additional comments (2)

bin/checkver.ps1 (2)

288-290: Good fix: clearing per-iteration state to prevent stale $page/$match.

This directly addresses the leakage described and ensures regex work on the intended payload each iteration.

---

409-415: No change needed — Invoke-AutoUpdate tolerates $null and empty @{ }

Get-VersionSubstitution in lib/autoupdate.ps1 checks $CustomMatches before calling GetEnumerator, so passing either $null or an empty hashtable is safe.