Add noNullProps option

packages/babel-plugin-htm/README.md

@@ -159,6 +159,17 @@ html`<div id="foo">hello ${you}</div>`
 ] }
 ```
 
+### `noNullProps` _(experimental)_
+
+Setting `noNullProps` to `true` passes empty object literals rather than `null` literals when a tag has no props:
+
+```js
+// input:
+html`<div />`
+// output:
+h('div', {})
+```
+
 
 [htm]: https://github.com/developit/htm
 [Babel docs]: https://babeljs.io/docs/en/babel-plugin-transform-react-jsx#pragma

packages/babel-plugin-htm/index.mjs

@@ -10,12 +10,14 @@ import { build, treeify } from '../../src/build.mjs';
  * @param {boolean} [options.useBuiltIns=false]  Use the native Object.assign instead of trying to polyfill it.
  * @param {boolean} [options.useNativeSpread=false]  Use the native { ...a, ...b } syntax for prop spreads.
  * @param {boolean} [options.variableArity=true] If `false`, always passes exactly 3 arguments to the pragma function.
+ * @param {boolean} [options.noNullProps=false] If `true`, passes an empty object instead of null when there are no props.
  */
 export default function htmBabelPlugin({ types: t }, options = {}) {
 	const pragmaString = options.pragma===false ? false : options.pragma || 'h';
 	const pragma = pragmaString===false ? false : dottedIdentifier(pragmaString);
 	const useBuiltIns = options.useBuiltIns;
 	const useNativeSpread = options.useNativeSpread;
+	const noNullProps = options.noNullProps;
 	const inlineVNodes = options.monomorphic || pragma===false;
 	const importDeclaration = pragmaImport(options.import || false);
 
@@ -123,7 +125,7 @@ export default function htmBabelPlugin({ types: t }, options = {}) {
 
 	function spreadNode(args, state) {
 		if (args.length === 0) {
-			return t.nullLiteral();
+			return noNullProps ? t.objectExpression([]) : t.nullLiteral();
 		}
 		if (args.length > 0 && t.isNode(args[0])) {
 			args.unshift({});

test/babel.test.mjs

@@ -360,6 +360,21 @@ describe('htm/babel', () => {
 		});
 	});
 
+	describe('{noNullProps:true}', () => {
+		test('should use empty objects instead of null props', () => {
+			expect(
+				transform('html`<div  />`;', {
+					...options,
+					plugins: [
+						[htmBabelPlugin, {
+							noNullProps: true
+						}]
+					]
+				}).code
+			).toBe(`h("div",{});`);
+		});
+	});
+
 	describe('{import:Object}', () => {
 		test('should add import', () => {
 			expect(