add a closing delimiter to the internal template syntax (#36)

otherwise ${...}1 would come out as dyn-$01, breaking
the index matching in /dyn-\$(\d+)/

src/html.js

···
 	}
 }
 
-const DYNAMIC_WHOLE = /^dyn-\$(\d+)$/i
-const DYNAMIC_GLOBAL = /dyn-\$(\d+)/gi
+const DYNAMIC_WHOLE = /^dyn-\$(\d+)\$$/i
+const DYNAMIC_GLOBAL = /dyn-\$(\d+)\$/gi
 
 /** @type {Map<TemplateStringsArray, CompiledTemplate>} */
 const templates = new Map()
···
 	if (cached) return cached
 
 	const templateElement = document.createElement('template')
-	templateElement.innerHTML = statics.reduce((a, v, i) => a + v + (i === statics.length - 1 ? '' : `dyn-$${i}`), '')
+	templateElement.innerHTML = statics.reduce((a, v, i) => a + v + (i === statics.length - 1 ? '' : `dyn-$${i}$`), '')
 
 	let nextPart = 0
 	/** @type {CompiledTemplate} */

test/basic.test.ts

···
 		const { root, el } = setup()
 
 		root.render(html`<!-- ${'text'} -->`)
-		expect(el.innerHTML).toMatchInlineSnapshot(`"<!-- dyn-$0 -->"`)
+		expect(el.innerHTML).toMatchInlineSnapshot(`"<!-- dyn-$0$ -->"`)
+	})
+
+	it('throws when manually specifying internal template syntax', { skip: import.meta.env.PROD }, () => {
+		const { root, el } = setup()
+
+		expect(() => {
+			root.render(html`${1} dyn-$0$`)
+		}).toThrowErrorMatchingInlineSnapshot(`[Error: got more parts than expected]`)
+
+		expect(el.innerHTML).toMatchInlineSnapshot(`""`)
+	})
+
+	it('does not throw when syntax is close but not exact', () => {
+		const { root, el } = setup()
+
+		root.render(html`dyn-$${0}1$`)
+
+		expect(el.innerHTML).toMatchInlineSnapshot(`"dyn-$01$"`)
 	})
 })