diff --git a/dom/indexedDB/test/unit/xpcshell-head-parent-process.js b/dom/indexedDB/test/unit/xpcshell-head-parent-process.js
index 17e2913ceb4a..8b4df69cb03a 100644
--- a/dom/indexedDB/test/unit/xpcshell-head-parent-process.js
+++ b/dom/indexedDB/test/unit/xpcshell-head-parent-process.js
@@ -542,16 +542,27 @@ function getPrincipal(url) {
   return Services.scriptSecurityManager.createContentPrincipal(uri, {});
 }
 
-function requestFinished(request) {
-  return new Promise(function(resolve, reject) {
-    request.callback = function(req) {
-      if (req.resultCode == Cr.NS_OK) {
-        resolve(req.result);
-      } else {
-        reject(req.resultCode);
-      }
+class RequestError extends Error {
+  constructor(resultCode, resultName) {
+    super(`Request failed (code: ${resultCode}, name: ${resultName})`);
+    this.name = "RequestError";
+    this.resultCode = resultCode;
+    this.resultName = resultName;
+  }
+}
+
+async function requestFinished(request) {
+  await new Promise(function(resolve) {
+    request.callback = function() {
+      resolve();
     };
   });
+
+  if (request.resultCode !== Cr.NS_OK) {
+    throw new RequestError(request.resultCode, request.resultName);
+  }
+
+  return request.result;
 }
 
 // TODO: Rename to openDBRequestSucceeded ?
diff --git a/dom/localstorage/test/helpers.js b/dom/localstorage/test/helpers.js
index ca3d383a2b82..69281b09df9c 100644
--- a/dom/localstorage/test/helpers.js
+++ b/dom/localstorage/test/helpers.js
@@ -62,14 +62,25 @@ function getLocalStorage() {
   return localStorage;
 }
 
-function requestFinished(request) {
-  return new Promise(function(resolve, reject) {
-    request.callback = SpecialPowers.wrapCallback(function(requestInner) {
-      if (requestInner.resultCode === SpecialPowers.Cr.NS_OK) {
-        resolve(requestInner.result);
-      } else {
-        reject(requestInner.resultCode);
-      }
+class RequestError extends Error {
+  constructor(resultCode, resultName) {
+    super(`Request failed (code: ${resultCode}, name: ${resultName})`);
+    this.name = "RequestError";
+    this.resultCode = resultCode;
+    this.resultName = resultName;
+  }
+}
+
+async function requestFinished(request) {
+  await new Promise(function(resolve) {
+    request.callback = SpecialPowers.wrapCallback(function() {
+      resolve();
     });
   });
+
+  if (request.resultCode !== SpecialPowers.Cr.NS_OK) {
+    throw new RequestError(request.resultCode, request.resultName);
+  }
+
+  return request.result;
 }
diff --git a/dom/localstorage/test/unit/head.js b/dom/localstorage/test/unit/head.js
index 0556c7b234df..234fbbb8452e 100644
--- a/dom/localstorage/test/unit/head.js
+++ b/dom/localstorage/test/unit/head.js
@@ -289,16 +289,27 @@ function getLocalStorage(principal) {
   );
 }
 
-function requestFinished(request) {
-  return new Promise(function(resolve, reject) {
-    request.callback = function(requestInner) {
-      if (requestInner.resultCode == Cr.NS_OK) {
-        resolve(requestInner.result);
-      } else {
-        reject(requestInner.resultCode);
-      }
+class RequestError extends Error {
+  constructor(resultCode, resultName) {
+    super(`Request failed (code: ${resultCode}, name: ${resultName})`);
+    this.name = "RequestError";
+    this.resultCode = resultCode;
+    this.resultName = resultName;
+  }
+}
+
+async function requestFinished(request) {
+  await new Promise(function(resolve) {
+    request.callback = function() {
+      resolve();
     };
   });
+
+  if (request.resultCode !== Cr.NS_OK) {
+    throw new RequestError(request.resultCode, request.resultName);
+  }
+
+  return request.result;
 }
 
 function loadSubscript(path) {
diff --git a/dom/quota/QuotaRequests.cpp b/dom/quota/QuotaRequests.cpp
index d03d7131334d..8f4c86bc25ed 100644
--- a/dom/quota/QuotaRequests.cpp
+++ b/dom/quota/QuotaRequests.cpp
@@ -74,6 +74,18 @@ RequestBase::GetResultCode(nsresult* aResultCode) {
   return NS_OK;
 }
 
+NS_IMETHODIMP
+RequestBase::GetResultName(nsACString& aResultName) {
+  AssertIsOnOwningThread();
+
+  if (!mHaveResultOrErrorCode) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mozilla::GetErrorName(mResultCode, aResultName);
+  return NS_OK;
+}
+
 UsageRequest::UsageRequest(nsIQuotaUsageCallback* aCallback)
     : mCallback(aCallback), mBackgroundActor(nullptr), mCanceled(false) {
   AssertIsOnOwningThread();
diff --git a/dom/quota/nsIQuotaRequests.idl b/dom/quota/nsIQuotaRequests.idl
index 0a8f606ffc6c..8b05717e834d 100644
--- a/dom/quota/nsIQuotaRequests.idl
+++ b/dom/quota/nsIQuotaRequests.idl
@@ -17,6 +17,8 @@ interface nsIQuotaRequestBase : nsISupports
   readonly attribute nsIPrincipal principal;
 
   [must_use] readonly attribute nsresult resultCode;
+
+  [must_use] readonly attribute ACString resultName;
 };
 
 [scriptable, uuid(166e28e6-cf6d-4927-a6d7-b51bca9d3469)]
diff --git a/dom/quota/test/common/content.js b/dom/quota/test/common/content.js
index 229a272aa2bd..d3927d649a00 100644
--- a/dom/quota/test/common/content.js
+++ b/dom/quota/test/common/content.js
@@ -47,14 +47,16 @@ function getSimpleDatabase() {
   return connection;
 }
 
-function requestFinished(request) {
-  return new Promise(function(resolve, reject) {
-    request.callback = SpecialPowers.wrapCallback(function(req) {
-      if (req.resultCode === SpecialPowers.Cr.NS_OK) {
-        resolve(req.result);
-      } else {
-        reject(req.resultCode);
-      }
+async function requestFinished(request) {
+  await new Promise(function(resolve) {
+    request.callback = SpecialPowers.wrapCallback(function() {
+      resolve();
     });
   });
+
+  if (request.resultCode != SpecialPowers.Cr.NS_OK) {
+    throw new RequestError(request.resultCode, request.resultName);
+  }
+
+  return request.result;
 }
diff --git a/dom/quota/test/common/global.js b/dom/quota/test/common/global.js
index 35bae1a1f3c9..ad73ce1d8bd1 100644
--- a/dom/quota/test/common/global.js
+++ b/dom/quota/test/common/global.js
@@ -3,6 +3,15 @@
  * http://creativecommons.org/publicdomain/zero/1.0/
  */
 
+class RequestError extends Error {
+  constructor(resultCode, resultName) {
+    super(`Request failed (code: ${resultCode}, name: ${resultName})`);
+    this.name = "RequestError";
+    this.resultCode = resultCode;
+    this.resultName = resultName;
+  }
+}
+
 function openDBRequestUpgradeNeeded(request) {
   return new Promise(function(resolve, reject) {
     request.onerror = function(event) {
diff --git a/dom/quota/test/common/system.js b/dom/quota/test/common/system.js
index 801ea81fdad5..36130725c56a 100644
--- a/dom/quota/test/common/system.js
+++ b/dom/quota/test/common/system.js
@@ -57,14 +57,16 @@ function getSimpleDatabase(principal, persistence) {
   return connection;
 }
 
-function requestFinished(request) {
-  return new Promise(function(resolve, reject) {
-    request.callback = function(req) {
-      if (req.resultCode == Cr.NS_OK) {
-        resolve(req.result);
-      } else {
-        reject(req.resultCode);
-      }
+async function requestFinished(request) {
+  await new Promise(function(resolve) {
+    request.callback = function() {
+      resolve();
     };
   });
+
+  if (request.resultCode !== Cr.NS_OK) {
+    throw new RequestError(request.resultCode, request.resultName);
+  }
+
+  return request.result;
 }
diff --git a/dom/quota/test/xpcshell/test_persist_globalLimit.js b/dom/quota/test/xpcshell/test_persist_globalLimit.js
index 56d875eba30a..8b15c26eaeb3 100644
--- a/dom/quota/test/xpcshell/test_persist_globalLimit.js
+++ b/dom/quota/test/xpcshell/test_persist_globalLimit.js
@@ -56,9 +56,12 @@ async function testSteps() {
       await requestFinished(request);
 
       ok(false, "Should have thrown");
-    } catch (ex) {
+    } catch (e) {
       ok(true, "Should have thrown");
-      ok(ex === NS_ERROR_FILE_NO_DEVICE_SPACE, "Threw right code");
+      ok(
+        e.resultCode === NS_ERROR_FILE_NO_DEVICE_SPACE,
+        "Threw right result code"
+      );
     }
 
     info("Closing the database and clearing");
diff --git a/dom/quota/test/xpcshell/test_persist_groupLimit.js b/dom/quota/test/xpcshell/test_persist_groupLimit.js
index d0cc86e04574..202726299f04 100644
--- a/dom/quota/test/xpcshell/test_persist_groupLimit.js
+++ b/dom/quota/test/xpcshell/test_persist_groupLimit.js
@@ -67,9 +67,12 @@ async function testSteps() {
       request = databases[index].write(new ArrayBuffer(1));
       await requestFinished(request);
       ok(false, "Should have thrown");
-    } catch (ex) {
+    } catch (e) {
       ok(true, "Should have thrown");
-      ok(ex == NS_ERROR_FILE_NO_DEVICE_SPACE, "Threw right code");
+      ok(
+        e.resultCode == NS_ERROR_FILE_NO_DEVICE_SPACE,
+        "Threw right result code"
+      );
     }
   }
 
diff --git a/dom/quota/test/xpcshell/test_storagePressure.js b/dom/quota/test/xpcshell/test_storagePressure.js
index 9a1f1c9706b3..2e95b2d749f5 100644
--- a/dom/quota/test/xpcshell/test_storagePressure.js
+++ b/dom/quota/test/xpcshell/test_storagePressure.js
@@ -84,9 +84,12 @@ async function testSteps() {
     await requestFinished(request);
 
     ok(false, "Should have thrown");
-  } catch (ex) {
+  } catch (e) {
     ok(true, "Should have thrown");
-    ok(ex === NS_ERROR_FILE_NO_DEVICE_SPACE, "Threw right code");
+    ok(
+      e.resultCode === NS_ERROR_FILE_NO_DEVICE_SPACE,
+      "Threw right result code"
+    );
   }
 
   info("Checking the storage pressure event");