fix tests

src/utils/test-helpers.js

@@ -0,0 +1,30 @@
+function checkFunc(dom, selector) {
+  if (typeof dom.update === 'function') {
+    const el = dom.update().find(selector);
+    if (el.exists()) {
+      return el;
+    }
+    return null;
+  }
+  const els = dom.querySelectorAll(selector);
+  if (els.length !== 0) {
+    return els;
+  }
+  return null;
+}
+
+
+export async function waitForSelection(dom, selector) {
+  let numSleep = 0;
+  for (;;) {
+    const el = checkFunc(dom, selector);
+    if (el) {
+      return el;
+    }
+    if (numSleep > 2) {
+      throw new Error(`could not find ${selector}`);
+    }
+    await new Promise(resolve => setTimeout(resolve, 250));
+    numSleep += 1;
+  }
+}