Modernize codebase: drop cross-fetch, require Node 18+, update tooling

.github/workflows/ci.yml

@@ -0,0 +1,26 @@
+name: CI
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        node-version: [18.x, 20.x, 22.x]
+    steps:
+      - uses: actions/checkout@v4
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: npm
+      - run: npm ci
+      - run: npm run format:check
+      - run: npm run typecheck
+      - run: npm run build
+      - run: npm test

README.md

@@ -2,24 +2,26 @@ QuickChart for Javascript
 ---
 [![npm](https://img.shields.io/npm/v/quickchart-js)](https://www.npmjs.com/package/quickchart-js)
 [![npm](https://img.shields.io/npm/dt/quickchart-js)](https://www.npmjs.com/package/quickchart-js)
-[![Build Status](https://travis-ci.com/typpo/quickchart-js.svg?branch=master)](https://travis-ci.com/typpo/quickchart-js)
+[![CI](https://github.com/typpo/quickchart-js/actions/workflows/ci.yml/badge.svg)](https://github.com/typpo/quickchart-js/actions/workflows/ci.yml)
 
 This is a Javascript client for [quickchart.io](https://quickchart.io), a web service for generating static charts.  View the main QuickChart repository [here](https://github.com/typpo/quickchart).
 
 # Installation
 
-If you are using npm:
-
 ```
 npm install quickchart-js
 ```
 
+Requires Node.js 18 or newer (the library uses the built-in `fetch`, so there are no runtime HTTP dependencies). It ships with CommonJS, ES module, and browser builds, plus TypeScript type definitions.
+
 # Usage
 
-This library provides a **QuickChart** object.  Import it, instantiate it, and set your [Chart.js](https://www.chartjs.org) config:
+This library provides a **QuickChart** object.  Import it, instantiate it, and set your [Chart.js](https://www.chartjs.org) config.
+
+Using ES modules or TypeScript:
 
 ```js
-const QuickChart = require('quickchart-js');
+import QuickChart from 'quickchart-js';
 
 const myChart = new QuickChart();
 myChart.setConfig({
@@ -28,6 +30,12 @@ myChart.setConfig({
 });
 ```
 
+Or using CommonJS:
+
+```js
+const QuickChart = require('quickchart-js');
+```
+
 Use `getUrl()` on your quickchart object to get the encoded URL that renders your chart:
 
 ```js
@@ -225,22 +233,28 @@ qc.setConfig({
 
 # Building the library
 
+Install dependencies:
+
+```
+npm install
+```
+
 To build this library locally, run:
 
 ```
-yarn build
+npm run build
 ```
 
 To run tests:
 
 ```
-yarn test
+npm test
 ```
 
 If you're editing the library and running examples, you may want to continuously build the library in the background:
 
 ```
-yarn build:watch
+npm run build:watch
 
 # ...