Generate UMD build. Fixes #27.

rollup.config.js

@@ -0,0 +1,42 @@
+import { nodeResolve } from '@rollup/plugin-node-resolve';
+import commonjs from '@rollup/plugin-commonjs';
+import babel from '@rollup/plugin-babel';
+export default [
+    {
+        input: 'src/index.js',
+        output: [
+            {
+                file: 'dist/index.js',
+                format: 'umd', // UMD version for browser, and for Node (for Jest testing)
+                name: 'U',
+            },
+            {
+                file: 'commonjs/index.js',
+                format: 'cjs', // CommonJS version for node? Not even sure this is required.
+            },
+            {
+                file: 'dist/index.esm.js',
+                format: 'esm', // ES2015 modules version so consumers can tree-shake
+            },
+        ],
+        plugins: [
+            commonjs(),
+            nodeResolve(),
+            babel({ babelHelpers: 'bundled' }),
+        ],
+    },
+    {
+        input: 'src/index.test.js',
+        output: [
+            {
+                file: 'commonjs/index.test.js',
+                format: 'cjs',
+            },
+        ],
+        plugins: [
+            commonjs(),
+            nodeResolve(),
+            babel({ babelHelpers: 'bundled' }),
+        ],
+    },
+];

src/index.js

@@ -1,6 +1,6 @@
-const kebabCase = require('kebab-case');
-const allProps = require('./keys.json');
-const jamSession = require('@mapbox/expression-jamsession');
+import kebabCase from 'kebab-case';
+// const allProps = require('./keys.json');
+import * as allProps from './keys';
 
 function isPaintProp(prop) {
     return allProps.paints.indexOf(prop) >= 0;
@@ -20,15 +20,6 @@ function whichProp(prop) {
     return 'other';
 }
 
-// this is the deprecated U`foo == blah` jam-session syntax.
-// function utils(...args) {
-//     if (args[0] && Array.isArray(args[0]) && args[0].raw) {
-//         // We're being used as a tagged template
-//         return jamSession.formulaToExpression(args[0].raw[0]);
-//     } else
-//         throw 'Mapbox-gl-utils unexpectedly called as a function. Use .init(map)';
-// }
-
 function parseSource(source) {
     if (
         String(source).match(/\.(geo)?json/) ||
@@ -737,6 +728,4 @@ function initClass(U) {
 const U = Utils.prototype;
 initClass(U);
 
-// Hmm. Using ES2015 export seems to play nicer with Webpack. But then testing within Node doesn't work. Sigh.
-// module.exports = Utils;
 export default Utils;

updateKeys.js

@@ -5,10 +5,11 @@ Should be run when new properties are added to that spec.
 
 const styleSpec = require('@mapbox/mapbox-gl-style-spec/reference/v8.json');
 const fs = require('fs');
-const styleSpecVersion = require('./node_modules/@mapbox/mapbox-gl-style-spec/package.json').version;
+const styleSpecVersion = require('./node_modules/@mapbox/mapbox-gl-style-spec/package.json')
+    .version;
 const out = {
     paints: [],
-    layouts: []
+    layouts: [],
 };
 Object.keys(styleSpec)
     .filter(x => /^paint_/.test(x))
@@ -17,10 +18,15 @@ Object.keys(styleSpec)
 Object.keys(styleSpec)
     .filter(x => /^layout_/.test(x))
     .forEach(key => out.layouts.push(...Object.keys(styleSpec[key])));
-    
+
 out.paints = Array.from(new Set(out.paints));
 out.layouts = Array.from(new Set(out.layouts));
 const outFile = 'dist/keys.json';
 fs.writeFileSync(outFile, JSON.stringify(out));
 
-console.log(`Wrote updated ${outFile} based on Mapbox-GL style spec ${styleSpecVersion}.`);
+const outFileJS = 'src/keys.js';
+fs.writeFileSync(outFileJS, 'module.exports = ' + JSON.stringify(out));
+
+console.log(
+    `Wrote updated ${outFile} based on Mapbox-GL style spec ${styleSpecVersion}.`
+);