Fix SC2129 shellcheck errors: use brace group redirects

[thpierce]

Summary

This PR fixes all SC2129 shellcheck warnings by replacing multiple individual redirects with brace group redirects, following shellcheck best practices.

What Changed

Before (SC2129 violation):

echo "VAR1=value1" >> $GITHUB_ENV
echo "VAR2=value2" >> $GITHUB_ENV
echo "VAR3=value3" >> $GITHUB_ENV

After (SC2129 compliant):

{
  echo "VAR1=value1"
  echo "VAR2=value2"
  echo "VAR3=value3"
} >> $GITHUB_ENV

Files Modified

Configuration:

• .github/workflows/pr-build.yml: Removed SC2129 from ignore list and comment

Workflow Files (17 files):

1. .github/workflows/dotnet-ec2-adot-sigv4-test.yml (line 144-147)
2. .github/workflows/dotnet-ec2-asg-test.yml (line 193-197)
3. .github/workflows/dotnet-ec2-default-test.yml (line 183-186)
4. .github/workflows/dotnet-ec2-nuget-test.yml (line 165-168)
5. .github/workflows/dotnet-ec2-windows-test.yml (line 182-186)
6. .github/workflows/java-ec2-adaptive-sampling-test.yml (line 135-139)
7. .github/workflows/java-ec2-adot-sigv4-test.yml (line 166-169)
8. .github/workflows/java-ec2-asg-test.yml (line 213-217)
9. .github/workflows/java-ec2-default-test.yml (line 204-207)
10. .github/workflows/java-ec2-ubuntu-test.yml (line 176-179)
11. .github/workflows/node-ec2-adot-sigv4-test.yml (line 159-162)
12. .github/workflows/node-ec2-asg-test.yml (line 196-200)
13. .github/workflows/node-ec2-default-test.yml (line 197-200)
14. .github/workflows/python-ec2-adaptive-sampling-test.yml (line 142-146)
15. .github/workflows/python-ec2-asg-test.yml (line 216-220)
16. .github/workflows/python-ec2-default-test.yml (line 206-209)
17. .github/workflows/python-ec2-genesis-test.yml (line 71-79)

Why This Change is Safe

This is a code quality improvement with no functional impact:

1. Identical Behavior: Brace group redirects produce exactly the same output as multiple individual redirects
2. Same Exit Codes: Both patterns preserve command exit codes identically
3. Same File Operations: Both create/append to files in the same way
4. No Logic Changes: Only the redirect syntax changed; all commands remain identical

Testing

Actionlint Validation

Command used:

actionlint -color -ignore SC2086 -ignore SC2004 -ignore SC2016 -ignore SC2010 -ignore SC2015 -ignore SC2260 -ignore SC2046 -ignore SC2181 .github/workflows/*.yml

Result: ✅ Exit code 0 (all SC2129 errors resolved)

Behavioral Tests

All tests passed confirming identical behavior:

Test 1: Basic multiple redirects

• ✅ PASS: Basic redirects produce identical output

Test 2: Command substitution

• ✅ PASS: Command substitution works identically (e.g., terraform output)

Test 3: Mixed variables and command substitution

• ✅ PASS: Mixed variables work identically

Test 4: Exit code preservation on success

• ✅ PASS: Exit codes match on success (both 0)

Test 5: File creation behavior

• ✅ PASS: Both create files identically

Test 6: Append to existing file

• ✅ PASS: Append behavior identical

What Each Test Validates

1. Output Equivalence: Verifies byte-for-byte identical file content
2. Command Substitution: Tests $(terraform output ...) patterns used in workflows
3. Variable Expansion: Tests $var patterns used in workflows
4. Exit Codes: Confirms error handling behavior is preserved
5. File Operations: Validates append mode works identically
6. Edge Cases: Tests file creation when file doesn't exist

Impact Assessment

Category: Code Quality Improvement

Risk Level: Minimal

• No functional changes to workflow logic
• No changes to environment variable values
• No changes to command execution order
• Comprehensive testing confirms behavioral equivalence

Benefits:

• Cleaner, more maintainable code
• Follows shellcheck best practices
• Reduces technical debt
• One less ignored shellcheck rule

Additional Notes

• This change affects only the syntax of how environment variables are written to $GITHUB_ENV
• All workflow functionality remains unchanged
• The brace group pattern is more efficient (opens file once vs multiple times)
• This is part of the systematic effort to remove shellcheck suppressions (see TODO comment in pr-build.yml)