test: add tests for keepOutputType option

src/render/emitter.ts

@@ -9,7 +9,11 @@ export class Emitter {
   }
 
   public write (html: any) {
-    if (this.keepOutputType && typeof html !== 'string') {
+    // This will only preserve the type if the value is isolated.
+    // I.E:
+    // {{ my-port }} -> 42
+    // {{ my-host }}:{{ my-port }} -> 'host:42'
+    if (this.keepOutputType === true && typeof html !== 'string' && this.html === '') {
       this.html = html
     } else {
       this.html += html as string