erode playground

Demo project for erode — a tool that detects architecture erosion in PRs by comparing code changes against an architecture model.

Architecture

frontend → api-gateway → user-service    → database
                       → product-service  → database

• frontend — Express server serving pages, fetches from api-gateway via HTTP
• api-gateway — Express server proxying to user-service and product-service via HTTP
• user-service — Express server managing users, imports database directly
• product-service — Express server managing products, imports database directly
• database — In-memory Map store (library, no server)

Setup

npm install
npm run build

Verifying with erode CLI

Test that the model is set up correctly before opening a PR.

LikeC4

# Parse and validate the LikeC4 model
npx likec4 export json -o /tmp/model.json likec4/

# List all components erode finds in the model
npx erode components /tmp/model.json

# Dry-run drift analysis on the current branch
npx erode analyze --model /tmp/model.json --diff "$(git diff main)"

Structurizr

The structurizr/ directory contains the same architecture in Structurizr format. workspace.dsl is the human-readable source; workspace.json is the pre-exported JSON that erode loads directly (no Java/Docker needed).

# Validate the Structurizr model
npx erode validate structurizr/workspace.json --model-format structurizr

# List all components
npx erode components structurizr/workspace.json --model-format structurizr

Architecture drift examples

These are the kinds of violations erode should catch:

• frontend adds fetch("http://user-service:3001/users") — bypasses api-gateway
• api-gateway adds import { findAll } from "@playground/database" — bypasses services
• product-service adds fetch("http://user-service:3001/users") — no relationship in model