EasyConverter

Client-side file conversion PWA. All conversions run entirely in the browser — no server, no uploads, fully offline-capable.

Features

• 16 formats supported: TXT, MD, HTML, RTF, CSV, JSON, XLSX, ODS, YAML, XML, Base64, PDF, PNG, JPEG, WEBP, EPUB
• 85+ conversion combinations with reliability classification and preflight warnings
• 100% client-side — your files never leave the browser
• Offline-first — installable PWA with Service Worker caching
• Bilingual — English and Italian with runtime language switching
• Mobile-first responsive design with Ionic components
• Pre-conversion preview for text and image files
• Quality feedback — reliability indicators and post-conversion summary

Supported Conversions

Source	Targets
TXT	MD, HTML, PDF, CSV, Base64
MD	TXT, HTML, PDF, Base64, EPUB
HTML	TXT, MD, PDF, CSV, XLSX, RTF, Base64, EPUB
RTF	TXT, HTML, MD, PDF, Base64
CSV	JSON, XLSX, TXT, MD, HTML, PDF, Base64, ODS, XML
JSON	CSV, XLSX, HTML, TXT, YAML, XML, Base64
XLSX	CSV, JSON, TXT, MD, HTML, PDF, Base64, ODS, XML
YAML	JSON, XML
XML	JSON, YAML, CSV, XLSX, HTML, TXT
Base64	TXT
PDF	TXT, MD, HTML, PNG, JPEG, WEBP
PNG	JPEG, WEBP, PDF, Base64
JPEG	PNG, WEBP, PDF, Base64
WEBP	PNG, JPEG, PDF, Base64
EPUB	TXT, HTML, MD, PDF, RTF, Base64

Conversions are classified by reliability: lossless, structured, text-only, best-effort, table-only, requires-uniform-data. Preflight checks warn users about potential data loss before converting.

Tech Stack

Layer	Technology
Framework	Angular 21 (NgModule)
UI	Ionic 8
Native bridge	Capacitor 8
Language	TypeScript 5.9 (strict)
PWA	Angular Service Worker
i18n	@ngx-translate/core
Testing	Karma + Jasmine (unit), Playwright (E2E)
Linting	ESLint 9 + Prettier
Deployment	Cloudflare Pages

Key Libraries

Library	Purpose
xlsx (SheetJS)	XLSX/ODS read/write via Web Worker
papaparse	CSV parsing with delimiter detection
marked	Markdown to HTML
turndown	HTML to Markdown
pdfjs-dist	PDF text extraction
pdf-lib	PDF creation
jszip	EPUB/ZIP handling
yaml	YAML parsing/serialization
fast-xml-parser	XML parsing/serialization
dompurify	HTML sanitization (XSS prevention)
juice	CSS inlining for HTML export
piexifjs	EXIF metadata handling

All heavy libraries are lazy-loaded on first use to keep the initial bundle small (~185 KB transfer).

Getting Started

Prerequisites

• Node.js 22+
• npm 10+

Install

git clone https://github.com/Spe1977/EasyConverterPWA.git
cd EasyConverterPWA
npm install

Development

npm start          # Dev server on http://localhost:4200

Build

npm run build      # Production build → www/

Test

npm test           # Unit tests (193 specs, Karma + Jasmine)
npm run lint       # ESLint
npm run format:check  # Prettier check

E2E Tests

npm run build                # Build first
npm run e2e:offline          # Playwright tests (Chromium, Firefox, WebKit)
npm run e2e:offline:ui       # Playwright with UI

E2E suite: 12 real conversion tests + 10 offline conversion tests across Chromium, Firefox, and WebKit.

Project Structure

src/
  app/
    core/
      models/           # ConversionFormat, ConversionResult
      services/         # ConverterService (orchestrator), format-specific services
    shared/
      components/       # FilePicker, FormatSelector, ProgressIndicator,
                        # LanguageSwitcher, UpdateNotification
    home/               # HomePage (main UI, lazy-loaded)
    app.module.ts       # Root module with i18n and SW config
  assets/
    i18n/               # en.json, it.json translation files
    _headers            # Cloudflare Pages security headers
    _redirects          # SPA routing for Cloudflare Pages
  environments/         # Dev/prod config with file size limits and timeouts
  theme/                # Ionic theme variables
playwright/             # E2E test specs

Architecture

• Single-page app with one lazy-loaded feature module (HomePage)
• Shared components are standalone, imported directly into the feature module
• State management via Angular signals (signal()) — no external state library
• Conversion pipeline — ConverterService orchestrates all conversions, delegating to format-specific services. Multi-step pipelines (e.g. RTF -> HTML -> PDF) are composed internally
• Web Worker for XLSX processing (off main thread) with synchronous fallback
• Preflight validation checks file content, warns about lossy conversions, blocks impossible ones
• Security — DOMPurify sanitization on HTML flows, formula injection mitigation in CSV/XLSX exports, CSP headers, 0 npm audit vulnerabilities

File Size Limits

Category	Limit
PDF	25 MB
Images	15 MB
Spreadsheets	15 MB
Text & structured data	20 MB
EPUB	20 MB
Base64	10 MB

Deployment

Configured for Cloudflare Pages with:

• Build command: npm run build
• Output directory: www
• Security headers (CSP, X-Frame-Options, HSTS-ready) via _headers
• SPA routing via _redirects
• Immutable caching for hashed assets, no-cache for Service Worker and index.html

License

MIT