Minor improvements for env_mirror.go

[Copilot]

Follow-up code quality improvements for environment variable mirroring added in #11980.

Changes

• Pre-sort at init: Sort MirroredEnvVars once in init() instead of on every call to GetMirroredEnvArgs() and GetMirroredEnvVarsList()
• Simplify test extraction: Replace manual character loop with strings.SplitN() for parsing KEY=${KEY} format
• Add PYENV_ROOT: Include Python environment variable for pyenv-based runner configurations

// Before: sorted on every call
func GetMirroredEnvArgs() []string {
    sortedVars := make([]string, len(MirroredEnvVars))
    copy(sortedVars, MirroredEnvVars)
    sort.Strings(sortedVars)
    // ...
}

// After: pre-sorted in init()
func init() {
    sort.Strings(MirroredEnvVars)
}

func GetMirroredEnvArgs() []string {
    // MirroredEnvVars is pre-sorted in init(), no need to sort here
    // ...
}

Original prompt

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This section details on the original issue you should resolve

<issue_title>Minor improvements for env_mirror.go</issue_title>
<issue_description>## Context

Follow-up from PR #11980 which added environment variable mirroring from runner to agent container.

Minor Improvements

1. Pre-sort MirroredEnvVars at initialization time

In pkg/workflow/env_mirror.go:108-110, the GetMirroredEnvArgs() function sorts the variable list on every call:

sortedVars := make([]string, len(MirroredEnvVars))
copy(sortedVars, MirroredEnvVars)
sort.Strings(sortedVars)

Suggestion: Either define MirroredEnvVars in sorted order in the source code, or sort once in an init() function. This is a minor optimization since the function is called once per workflow compilation.

2. Simplify test code variable extraction

In pkg/workflow/env_mirror_test.go:44-52, the variable name extraction could use strings.SplitN() for clarity:

// Current:
for j := 0; j < len(envAssignment); j++ {
    if envAssignment[j] == '=' {
        varSet[envAssignment[:j]] = true
        break
    }
}

// Simpler:
parts := strings.SplitN(envAssignment, "=", 2)
varSet[parts[0]] = true

3. Consider adding PYENV_ROOT

Python environment setup sometimes uses PYENV_ROOT on certain runner configurations. Consider adding it to the mirrored variables list if relevant for Python workflows.

Priority

Low - these are minor code quality improvements, not functional issues.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Minor improvements for env_mirror.go #12087

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[github-actions]

🔍 PR Triage Results

Category: refactor | Risk: medium | Priority: 37/100

Scores Breakdown

• Impact: 22/50 - Code quality improvement
• Urgency: 5/30 - Recent PR
• Quality: 10/20 - CI status unknown

📋 Recommended Action: batch_review

This PR contains minor code quality improvements to the env_mirror.go implementation:

Changes:

1. Pre-sort MirroredEnvVars in init() instead of on every call (performance optimization)
2. Simplify test code with strings.SplitN() (readability improvement)
3. Add PYENV_ROOT environment variable (completeness)

All improvements are low-risk refactoring with no functional changes. Touches 140 files due to workflow recompilation.

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Triaged by PR Triage Agent on 2026-01-28T00:34:49Z

AI generated by PR Triage Agent