History Analysis Reference

Advanced features, caching behavior, and best practices.

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Cache Behavior

When Cache is Used

# Default: Use cache if exists and fresh
/sourceatlas:history

# Check logic:
if [ -f ".sourceatlas/history.md" ]; then
  age_days=$(calculate_age_in_days)
  if [ $age_days -eq 0 ]; then
    echo "📁 Loading from cache (today)"
  elif [ $age_days -eq 1 ]; then
    echo "📁 Loading from cache (1 day ago)"
  else
    echo "📁 Loading from cache ($age_days days ago)"
  fi
  # If >30 days, warn user
  if [ $age_days -gt 30 ]; then
    echo "⚠️ Cache is older than 30 days, recommend re-analysis"
  fi
  # Output cached content
  exit 0
fi

When Cache is Skipped

# Force flag: Always skip cache
/sourceatlas:history --force
# → Executes full analysis even if cache exists

# No cache: First time analysis
# → .sourceatlas/history.md doesn't exist yet

Cache File Naming

Unlike other commands, history has fixed cache path:

# Always the same
.sourceatlas/history.md

Rationale: History analysis is repository-wide, doesn't vary by target.

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Auto-Save Behavior

File Structure

.sourceatlas/
└── history.md              # Fixed filename

Save Timing

Auto-save occurs immediately after Step V4 verification:

# After verification passes
verification_summary:
  confidence_level: "high"

# Then auto-save
💾 Saved to .sourceatlas/history.md

What Gets Saved

Complete Markdown output including:

• Header with analysis period and counts
• Hotspots table (top 10)
• Temporal coupling table
• Recent contributors knowledge map
• Risk summary
• Recommendations
• Verification summary

Format: Full Markdown as specified in output-template.md

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Handoffs: When to Suggest Next Commands

After Hotspot Identification

If high-risk hotspots found (complexity >10,000):

Suggest:

| # | Command | Purpose |
|---|---------|---------|
| 1 | `/sourceatlas:impact "src/core/processor.ts"` | processor.ts changed 45 times, need to understand dependencies |

After Suspicious Coupling Found

If cross-module coupling detected (degree >0.6):

Suggest:

| # | Command | Purpose |
|---|---------|---------|
| 1 | `/sourceatlas:flow "src/orders/checkout"` | Suspicious coupling with payments, trace execution flow |

After Bus Factor Risk Found

If single-contributor modules identified:

Suggest:

| # | Command | Purpose |
|---|---------|---------|
| 1 | `/sourceatlas:pattern "legacy patterns"` | Bus factor risk in legacy/, need to understand patterns before knowledge transfer |

When to Stop (No Recommendations)

• History too short: <50 commits or <3 months
• No significant patterns: All coupling <0.5, all hotspots <10 revisions
• Analysis depth sufficient: User already ran 4+ commands

Output instead:

⚠️ **Insufficient Data Warning**
- Commits: 38 (recommend ≥50)
- Period: 67 days (recommend ≥90 days)

Recommend analyzing temporal patterns again in 3-6 months

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code-maat Installation

Default Installation Location

$HOME/.sourceatlas/bin/code-maat-1.0.4-standalone.jar

Environment Variable

export CODEMAAT_JAR="$HOME/.sourceatlas/bin/code-maat-1.0.4-standalone.jar"

Installation Script

./scripts/install-codemaat.sh

What it does:

1. Creates ~/.sourceatlas/bin/
2. Downloads code-maat JAR from GitHub releases
3. Sets executable permissions
4. Verifies installation

Manual Installation

If automatic installation fails:

# 1. Download from GitHub
wget https://github.com/adamtornhill/code-maat/releases/download/v1.0.4/code-maat-1.0.4-standalone.jar

# 2. Create directory
mkdir -p ~/.sourceatlas/bin/

# 3. Move JAR
mv code-maat-1.0.4-standalone.jar ~/.sourceatlas/bin/

# 4. Set environment variable
export CODEMAAT_JAR="$HOME/.sourceatlas/bin/code-maat-1.0.4-standalone.jar"

Prerequisites

Java 8+ required:

# Check Java version
java -version

# Install if missing (macOS)
brew install openjdk@11

# Install if missing (Ubuntu)
sudo apt-get install openjdk-11-jdk

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Analysis Parameters

Time Range

Default: Last 12 months

git log --after="$(date -v-12m +%Y-%m-%d)" ...

Custom time range:

# Last 6 months
/sourceatlas:history "last 6 months"

# Last 18 months
/sourceatlas:history "last 18 months"

Parsing logic:

# Extract number from arguments
MONTHS=$(echo "$ARGUMENTS" | grep -o '[0-9]\+')
if [ -z "$MONTHS" ]; then
  MONTHS=12  # Default
fi

Scope Filtering

Default: Entire repository

Custom scope:

# Specific directory
/sourceatlas:history "src/"

# Multiple directories (future enhancement)
/sourceatlas:history "src/ lib/"

Implementation:

if [ -n "$SCOPE" ]; then
  git log --all --numstat ... -- "$SCOPE" > /tmp/git-history.log
else
  git log --all --numstat ... > /tmp/git-history.log
fi

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Interpretation Guidelines

Hotspots

Not always bad:

• Core logic files naturally change often
• Configuration files updated for environments
• Test files should mirror production changes

Red flags:

• High complexity score (>10,000)
• Hotspot without corresponding test changes
• Frequent changes without documentation updates

Temporal Coupling

Expected (normal):

• Model ↔ Service (same domain)
• Route ↔ Controller (MVC pattern)
• Component ↔ Component styles
• Test ↔ Production code

Suspicious (review needed):

• Cross-layer: API ↔ Database
• Cross-module: User ↔ Payment
• Backend ↔ Frontend (if separated)

Contributors

Healthy distribution:

• 2-3 active contributors per module
• Regular activity (monthly commits)
• Knowledge overlap between contributors

Bus factor risks:

• Single contributor (especially if inactive >6 months)
• Primary contributor left team
• No knowledge overlap in critical modules

---

Performance Optimization

For Large Repositories (>10K commits)

# Limit analysis to recent history
git log --all --numstat --date=short \
    --pretty=format:'--%h--%ad--%aN' \
    --after="$(date -v-6m +%Y-%m-%d)" \
    --max-count=1000 \
    > /tmp/git-history.log

For Monorepos

# Analyze specific package only
git log --all --numstat --date=short \
    --pretty=format:'--%h--%ad--%aN' \
    -- "packages/app/" \
    > /tmp/git-history.log

# Or analyze multiple related packages
git log --all --numstat --date=short \
    --pretty=format:'--%h--%ad--%aN' \
    -- "packages/app/" "packages/shared/" \
    > /tmp/git-history.log

For Slow code-maat Execution

# Use faster analysis types
# revisions: Fast (seconds)
# coupling: Moderate (seconds to minutes)
# entity-ownership: Slow (minutes)

# Skip entity-ownership if too slow
# Focus on revisions + coupling

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Edge Cases

Case 1: No Git History

# Check if git repository
if ! git rev-parse --git-dir > /dev/null 2>&1; then
    echo "❌ Not a git repository"
    echo "History analysis requires git version control"
    exit 1
fi

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Case 2: Very Short History (<50 commits)

output:
  message: |
    ⚠️ Only 38 commits found in analysis period

    Temporal analysis works best with >50 commits.

    Consider:
    - Extending time range (e.g., --after="2 years ago")
    - Analyzing entire repository history (omit --after)
    - Waiting for more development activity

---

Case 3: Monolithic Commits

If commits are very large (>100 files per commit):

warning: |
  Large, infrequent commits detected.

  This may affect coupling analysis accuracy:
  - Many files change together in single commit
  - Hard to distinguish real vs coincidental coupling

  Recommend:
  - Smaller, atomic commits going forward
  - Focus on hotspot analysis (more reliable)

---

Case 4: Multiple Contributors with Same Name

# If "Alice" appears as:
# - Alice Smith <alice@company.com>
# - Alice Johnson <alice@contractor.com>

# code-maat uses author name only, may merge stats
# Verify in git log:
git log --format='%aN <%aE>' | sort -u | grep -i alice

Action: If ambiguous, note in output:

Note: Multiple contributors with name "Alice" found.
Stats may be aggregated.

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Constitutional Compliance

Article I: Evidence-Based Analysis

• ✅ Every hotspot must have actual revision count
• ✅ Coupling degrees from code-maat output
• ✅ Contributor names from git log

Article II: Directory Exclusions

• ✅ Git log naturally excludes untracked files
• ✅ code-maat processes committed files only

Article III: Verification Required

• ✅ Execute verification-guide.md before output
• ✅ Re-verify after corrections

Article IV: Evidence Format

• ✅ Use file:line for hotspots
• ✅ Reference commit hashes where relevant
• ✅ Include coupling degrees in output

Article V: Transparency

• ✅ Show cache age: "Loading from cache (2 days ago)"
• ✅ Show analysis period explicitly
• ✅ Note if history insufficient

Article VI: Scale Awareness

• ✅ Limit analysis to 12 months by default
• ✅ Cap hotspot list to top 10
• ✅ Filter coupling to degree ≥0.5

Article VII: User Empowerment

• ✅ Provide actionable recommendations
• ✅ Suggest next commands based on findings
• ✅ Include priority actions in risk summary

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Related Commands

After history analysis, consider:

• /sourceatlas:impact "[hotspot]" - Understand dependencies of frequently changed files
• /sourceatlas:pattern "[pattern]" - Learn patterns used in hotspots before refactoring
• /sourceatlas:flow "[entry point]" - Trace execution through coupled modules
• /sourceatlas:overview - Get broader context if history reveals complexity

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Troubleshooting

Issue: code-maat Not Found

Symptom: CODEMAAT_JAR not set or file not found

Debug:

# Check environment
echo $CODEMAAT_JAR

# Check default location
ls -la ~/.sourceatlas/bin/code-maat-*.jar

# Verify Java
java -version

Fix: Run installation script or set environment variable

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Issue: Empty Git Log

Symptom: 0 commits found

Debug:

# Check git repository
git log --oneline | head -5

# Check date filter
date -v-12m +%Y-%m-%d  # macOS
date -d '12 months ago' +%Y-%m-%d  # Linux

Fix: Adjust date range or check if repository has history

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Issue: code-maat Fails

Symptom: Exception in thread "main" or Java errors

Debug:

# Test code-maat directly
java -jar "$CODEMAAT_JAR" -h

# Check git log format
head -20 /tmp/git-history.log

Fix:

• Verify Java version (need 8+)
• Regenerate git log with correct format
• Re-download code-maat JAR if corrupted

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Issue: No Significant Patterns

Symptom: All couplings <0.3, all hotspots <5 revisions

Possible causes:

1. Very stable codebase (good!)
2. Short history period
3. Large, infrequent commits hiding patterns

Action:

✅ No significant temporal patterns detected.

This could mean:
- Clean architecture with good separation
- Young codebase with limited history
- Stable, mature codebase

Consider re-analyzing after more development activity.

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Best Practices

1. Run quarterly - Temporal patterns evolve over time
2. Compare with previous runs - Track if hotspots are growing
3. Act on bus factor risks - Document before knowledge is lost
4. Review coupling trends - Monitor if architecture is degrading
5. Cross-reference with static analysis - Combine history + impact for complete picture