pouchdb

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15 units • 5 levels

Change Guide

Welcome to pouchdb

Your guide to understanding the codebase

5 levels

15 learning units

Orchestration & APIs

  • Pipelines, workflows, public interfaces • 3 units

Document Operations & Data Model

  • API·7

PouchDB Core Architecture

  • Architecture·2

Essential Patterns & Utilities

  • Patterns·4

Core Logic & Data

  • Business rules, schemas, models • 3 units

Changes Feed & Query System

  • API·7

Integration Layer

  • Integration·12

Replication & Sync Protocol

  • Workflow·6

Interaction & Integration

  • UI components, external connectors • 2 units

Comprehensive Test Architecture

  • Testing·5

Storage & Migration Systems

  • Testing·7

Cross-Cutting Concerns

  • Auth, logging, config, testing • 2 units

Advanced Concurrency & Documentation

  • Concurrency·27

Performance & Reliability Testing

  • Testing·15

Edge Cases & Resilience

  • Error handling, fault tolerance • 2 units

Additional Data Model Patterns

  • Data Model·2

Additional Error Handling Patterns

  • Error Handling

Test Your Knowledge

24 questions across all levels

Progress 0/24 answered

Levels

  • Level 1: 6
  • Level 2: 6
  • Level 3: 6
  • Level 4: 6

Hands-On Assignment

2-3 hours

Your Challenge

Implement a document versioning plugin that maintains a complete history of document changes in a separate collection. When a document is updated or deleted, your plugin should automatically store the previous version in a {dbname}_history database with metadata about the change (timestamp, operation type, revision). This will allow developers to query historical versions and potentially restore previous states.

Starting Points

  • CONTRIBUTING.md:1-72 Understand the project structure and how to set up your development environment for building and testing plugins

  • bin/build-module.js:1-66 Study how PouchDB modules are built and packaged - your plugin will follow similar patterns

  • bin/build-node.sh:1-7 See how the build process works for Node.js modules

Success Criteria

  • Plugin successfully intercepts put, post, and remove operations without breaking existing functionality
  • Previous document versions are stored in a separate {dbname}_history database with proper metadata
  • A getHistory(docId) method returns all historical versions of a document in chronological order
  • A restoreVersion(docId, timestamp) method can restore a document to a previous state
  • The plugin can be built using the existing build system (npm run build works)
  • History entries include: original document content, revision, timestamp, and operation type
  • Plugin handles edge cases: first document creation, missing history db, and deleted documents

Hints

  • Hint 1: Understanding PouchDB's plugin architecture conceptually
  • Hint 2: Accessing document state before changes implementation
  • Hint 3: Managing the history database implementation
  • Hint 4: Plugin structure and API code location
  • Hint 5: Handling edge cases conceptually

Prerequisites

  • JavaScript promises and async/await
  • PouchDB basic operations (put, get, remove)
  • Plugin architecture patterns
  • Document revision system basics

pouchdb - Learning Path