Justfile Advanced Patterns

Advanced Patterns (Level 3)

Production systems. Git-aware testing, deployment integration, migrations, observability.

Commands

test-smart

Git-aware test execution. Conditional expensive tests based on changed files.

# Smart test execution (conditional component tests based on git changes)
test-smart mode="default":
    @scripts/test-smart.sh {{mode}}

Implementation (scripts/test-smart.sh):

#!/usr/bin/env bash
set -euo pipefail

MODE="${1:-default}"

# Always run fast unit tests
echo "🧪 Unit tests (always)..."
pnpm vitest run --project unit --reporter=verbose

# Determine if component tests needed
NEED_COMPONENT=false

case "$MODE" in
  staged)   CHANGED=$(git diff --cached --name-only --diff-filter=ACMR || echo "") ;;
  push)     CHANGED=$(git diff --name-only origin/main...HEAD || echo "") ;;
  *)        CHANGED=$(git diff --name-only HEAD || echo "")
            CHANGED+=$'\n'$(git diff --cached --name-only --diff-filter=ACMR || echo "") ;;
esac

# Check if component-related files changed
if echo "$CHANGED" | grep -qE "src/(components|design-system|pages)/.*\.tsx?$"; then
  NEED_COMPONENT=true
fi

# Run component tests if needed
if [ "$NEED_COMPONENT" = true ]; then
  echo "🎨 Component changes detected..."
  pnpm vitest run --project component --reporter=verbose
else
  echo "⏭️  No component changes"
fi

Usage:

just test-smart         # Default (working + staged)
just test-smart staged  # Pre-commit hook
just test-smart push    # Pre-push hook

deploy

Deploy to environment. Cloud provider integration.

# Deploy to environment (default: dev)
deploy environment="dev":
    @scripts/deploy/check-auth.sh {{environment}}
    @scripts/deploy/full.sh {{environment}}

Auth check (scripts/deploy/check-auth.sh):

#!/usr/bin/env bash
set -euo pipefail

ENV="${1:-dev}"

# Check gcloud auth
if ! gcloud auth list --filter=status:ACTIVE >/dev/null 2>&1; then
  echo "❌ Not authenticated"
  exit 1
fi

# Check project
EXPECTED="myproject-$ENV"
CURRENT=$(gcloud config get-value project 2>/dev/null)

if [ "$CURRENT" != "$EXPECTED" ]; then
  echo "❌ Wrong project"
  echo "   Expected: $EXPECTED"
  echo "   Current:  $CURRENT"
  exit 1
fi

echo "✅ Authenticated: $(gcloud auth list --filter=status:ACTIVE --format='value(account)')"

Partial deploys:

deploy-api environment="dev":
    @scripts/deploy/api.sh {{environment}}

deploy-web environment="dev":
    @scripts/deploy/web.sh {{environment}}

migrate

Database migrations. Apply, rollback, create, history.

# Apply database migrations
migrate:
    <apply all pending migrations>

# Rollback last migration
migrate-down:
    <rollback one migration>

# Create new migration
migrate-create message:
    <generate migration with description>

# View migration history
migrate-history:
    <show applied migrations timeline>

Python (Alembic):

migrate:
    uv run alembic upgrade head

migrate-down:
    uv run alembic downgrade -1

migrate-create message:
    uv run alembic revision --autogenerate -m "{{message}}"

migrate-history:
    uv run alembic history --verbose

Migration testing:

test-migration:
    uv run pytest -v -m "migration" --durations=10

logs

Service logs. Tail cloud logs.

# View service logs
logs service="api" environment="dev":
    @scripts/gcp/logs.sh {{service}} {{environment}}

Implementation:

#!/usr/bin/env bash
SERVICE="${1:-api}"
ENV="${2:-dev}"

gcloud logging tail \
  "resource.type=cloud_run_revision AND resource.labels.service_name=$ENV-$SERVICE" \
  --project="myproject-$ENV" \
  --format="table(timestamp, textPayload)"

status

Deployment health check.

# Check deployment status
status environment="dev":
    @scripts/gcp/status.sh {{environment}}

Implementation:

#!/usr/bin/env bash
ENV="${1:-dev}"

echo "Services:"
gcloud run services list \
  --project="myproject-$ENV" \
  --format="table(SERVICE,URL,LAST_DEPLOYED)"

Pattern: Git-Aware Testing

Problem: Full test suite slow (unit 3s, component 18s). Running all tests every commit slows development.

Solution: Conditionally run expensive tests based on git diff.

Modes:

• default: Working directory + staged
• staged: Staged files only (pre-commit)
• push: Commits since origin/main (pre-push)

Benefits:

• Fast feedback (3s typical)
• Comprehensive when needed (21s UI changes)
• Safe (always runs unit tests)

Pattern: Deployment Integration

Deployment as first-class justfile command. No context switching to console/scripts.

Commands:

• deploy - Full deployment
• deploy-api, deploy-web - Partial (fast iteration)
• logs - Debugging
• status - Health check

Safety:

• Auth checking before deploy
• Default to dev environment
• Explicit production deploys
• Tag images with git SHA

Pattern: Migration Management

Migrations alongside tests/builds. First-class development operation.

Workflow:

1. Create migration: just migrate-create "add users table"
2. Apply locally: just migrate
3. Test: just test-migration
4. Deploy with migrations: deployment script runs migrate

Testing:

@pytest.mark.migration
def test_upgrade_downgrade_cycle():
    downgrade(config, "base")
    upgrade(config, "head")
    downgrade(config, "-1")
    upgrade(config, "head")

When to Add Level 3

Add when:

• Deploying to production
• Database-backed application
• Slow test suites (need optimization)
• Cloud-native systems

Skip when:

• No deployment workflows
• No database
• Fast test suites already
• Static sites/libraries

Cloud Provider Examples

GCP (Cloud Run): Examples above

AWS (ECS):

deploy environment="dev":
    aws ecs update-service --cluster {{environment}} --service api --force-new-deployment

Azure (Container Apps):

deploy environment="dev":
    az containerapp update --name api --resource-group {{environment}} --image {{image}}

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