test - poll for element instead of manual timeouts

1 files changed, 53 insertions, 0 deletions

diff --git a/test/lib/util.js b/test/lib/util.js
new file mode 100644
index 000000000..626280745
--- /dev/null
+++ b/test/lib/util.js
@@ -0,0 +1,53 @@
+module.exports = {
+  timeout,
+  queryAsync,
+  findAsync,
+  pollUntilTruthy,
+}
+
+function timeout (time) {
+  return new Promise((resolve, reject) => {
+    setTimeout(resolve, time || 1500)
+  })
+}
+
+async function findAsync(container, selector, opts) {
+  try {
+    return await pollUntilTruthy(() => {
+      const result = container.find(selector)
+      if (result.length > 0) return result
+    }, opts)
+  } catch (err) {
+    throw new Error(`Failed to find element within interval: "${selector}"`)
+  }
+}
+
+async function queryAsync(jQuery, selector, opts) {
+  try {
+    return await pollUntilTruthy(() => {
+      const result = jQuery(selector)
+      if (result.length > 0) return result
+    }, opts)
+  } catch (err) {
+    throw new Error(`Failed to find element within interval: "${selector}"`)
+  }
+}
+
+async function pollUntilTruthy(fn, opts = {}){
+  const pollingInterval = opts.pollingInterval || 100
+  const timeoutInterval = opts.timeoutInterval || 5000
+  const start = Date.now()
+  let result
+  while (!result) {
+    // check if timedout
+    const now = Date.now()
+    if ((now - start) > timeoutInterval) {
+      throw new Error(`pollUntilTruthy - failed to return truthy within interval`)
+    }
+    // check for result
+    result = fn()
+    // run again after timeout
+    await timeout(pollingInterval, timeoutInterval)
+  }
+  return result
+}