skills/docs/worklogs/2026-01-02-agent-update-tests-and-bug-fix.md

title	date	keywords	commits	compression_status
Agent File Update Tests and Section Ordering Bug Fix	2026-01-02	testing bash agent-context bug-fix state-machine specify	1	uncompressed

Session Summary

Date: 2026-01-02 Focus Area: Add comprehensive tests for agent file update logic and fix discovered bug

Accomplishments

• Created test-agent-update.sh with 33 test cases
• Discovered and fixed bug in update-agent-context.sh section ordering
• Tests cover: basic functionality, missing sections, timestamps, idempotency, change limits, DB entries, placement, edge cases
• Closed skills-hgm (Add tests for agent file update logic)
• Previous session: Completed skills-x33 (branch name tests - 27 tests)

Key Decisions

Decision 1: Test extraction approach using awk instead of sed

• Context: Need to extract functions from update-agent-context.sh for isolated testing
• Options considered:
  1. sed -n '/^function()/,/^}$/p' - Original approach
  2. awk '/^function\(\)/,/^}$/ {print; if (/^}$/) exit}' - More precise
  3. Source entire script with mocked dependencies
• Rationale: awk with explicit exit on closing brace is more reliable for multi-function scripts
• Impact: Clean function extraction without pulling in adjacent functions

Decision 2: Fix the bug rather than document as expected behavior

• Context: Found that Recent Changes section was silently skipped when preceded by Active Technologies
• Rationale: This was clearly unintended behavior - the code was supposed to update both sections
• Impact: Agent context files now correctly receive change entries regardless of section ordering

Problems & Solutions

Problem	Solution	Learning
eval/sed extraction didn't work correctly for update_existing_agent_file	Used awk with explicit exit on ^}$ pattern	awk is more precise for function boundary detection
Tests failing: change entries not added to existing Recent Changes	Traced through code, found ## Recent Changes caught by generic "close tech section on any ##" logic	State machine section handlers must check specific headers before generic patterns
Idempotency test counting wrong pattern	Pattern "Python + Django" appeared in both tech and change sections	Use anchored regex ^- pattern$ for specific line matching

Technical Details

Code Changes

• Total files modified: 2
• Key files changed:
  • .specify/scripts/bash/update-agent-context.sh - Fixed section ordering in while loop
  • .specify/scripts/bash/tests/test-agent-update.sh - New test file (33 tests)

The Bug

The update_existing_agent_file function processes files line-by-line with a state machine. When in the Active Technologies section (in_tech_section=true), encountering any ## header would:

1. Add pending tech entries
2. Echo the header line
3. Set in_tech_section=false
4. Continue to next iteration ← Bug here!

This meant ## Recent Changes was echoed but the change entry addition code (which checks if [[ "$line" == "## Recent Changes" ]]) was never reached.

Fix: Check for ## Recent Changes BEFORE the generic "any ## closes tech section" logic:

# Handle Recent Changes section FIRST (before generic ## handling)
if [[ "$line" == "## Recent Changes" ]]; then
    # Close tech section if we were in it
    if [[ $in_tech_section == true ]]; then
        if [[ $tech_entries_added == false ]] && [[ ${#new_tech_entries[@]} -gt 0 ]]; then
            printf '%s\n' "${new_tech_entries[@]}" >> "$temp_file"
            tech_entries_added=true
        fi
        in_tech_section=false
    fi
    echo "$line" >> "$temp_file"
    # Add new change entry right after the heading
    if [[ -n "$new_change_entry" ]]; then
        echo "$new_change_entry" >> "$temp_file"
    fi
    ...
fi

Test Categories

1. Basic Functionality (4 tests) - Tech/change entries added, existing content preserved
2. Missing Sections (6 tests) - Creates sections when absent
3. Timestamp Updates (2 tests) - Updates **Last updated**: dates
4. Idempotency (1 test) - No duplicates when re-running
5. Change Entry Limits (5 tests) - Max 2 existing changes kept
6. Database Entries (3 tests) - DB-only additions work
7. Tech Entry Placement (3 tests) - Entries at correct position
8. Edge Cases (5 tests) - Empty, NEEDS CLARIFICATION, EOF handling
9. format_technology_stack (4 tests) - Helper function unit tests

Commands Used

# Run the tests
bash .specify/scripts/bash/tests/test-agent-update.sh

# Debug function extraction
eval "$(awk '/^update_existing_agent_file\(\)/,/^}$/ {print; if (/^}$/) exit}' script.sh)"

# Trace execution
bash -x -c '...'

Process and Workflow

What Worked Well

• Test-first debugging: Writing tests exposed the bug immediately
• Incremental tracing: Adding debug output to narrow down the issue
• Hypothesis testing: Created minimal test cases to verify the bug cause

What Was Challenging

• Function extraction: eval/sed patterns are finicky with nested braces
• Understanding state machine flow: Had to trace through manually to find where continue was short-circuiting

Learning and Insights

Technical Insights

• Bash state machines need careful ordering: specific cases before generic patterns
• continue in while loops can silently skip subsequent handlers
• Test fixtures with setup_test_file() using heredocs are clean for bash testing
• grep patterns for line counting need anchoring to avoid false positives

Process Insights

• When tests fail unexpectedly, the code might be buggy (not just the tests)
• Adding debug output (echo "DEBUG: ..." >&2) is fast way to trace bash

Context for Future Work

Open Questions

• Should we add more tests for create_new_agent_file function?
• Consider shellcheck/shfmt for the test files?

Next Steps

• skills-s92: Add tests for deploy-skill.sh (continues testing theme)
• skills-7bu: Add atomic file operations (related to file update code)
• Rebuild home-manager to deploy updated script

Related Work

• 2026-01-01-ops-review-phase-3-and-worklog-migration.md - Previous session
• skills-x33: Branch name tests (27 tests, completed in prior session)

Raw Notes

• The deployed worklog skill still uses .org format; repo has .md
• Network issue prevented bd sync (192.168.1.108:3000 unreachable)
• Total test count across both test files: 60 tests (27 branch + 33 agent)

Session Metrics

• Commits made: 1
• Files touched: 2
• Lines added/removed: +536/-13
• Tests added: 33
• Tests passing: 33/33