diff --git a/toolkit/components/search/tests/xpcshell/head_search.js b/toolkit/components/search/tests/xpcshell/head_search.js
index dc5522dd660a..4cb0a3fbbbe7 100644
--- a/toolkit/components/search/tests/xpcshell/head_search.js
+++ b/toolkit/components/search/tests/xpcshell/head_search.js
@@ -1,12 +1,17 @@
 /* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
 /* vim:set ts=2 sw=2 sts=2 et: */
 
-Components.utils.import("resource://gre/modules/Services.jsm");
-Components.utils.import("resource://gre/modules/NetUtil.jsm");
-Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
-Components.utils.import("resource://gre/modules/FileUtils.jsm");
-Components.utils.import("resource://gre/modules/Promise.jsm");
-Components.utils.import("resource://testing-common/AppInfo.jsm");
+const { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
+
+Cu.import("resource://gre/modules/FileUtils.jsm");
+Cu.import("resource://gre/modules/osfile.jsm");
+Cu.import("resource://gre/modules/NetUtil.jsm");
+Cu.import("resource://gre/modules/Promise.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/Task.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://testing-common/AppInfo.jsm");
+Cu.import("resource://testing-common/httpd.js");
 
 const BROWSER_SEARCH_PREF = "browser.search.";
 const NS_APP_SEARCH_DIR = "SrchPlugns";
@@ -42,6 +47,17 @@ function removeMetadata()
   }
 }
 
+function getSearchMetadata()
+{
+  // Check that search-metadata.json has been created
+  let metadata = gProfD.clone();
+  metadata.append("search-metadata.json");
+  do_check_true(metadata.exists());
+
+  do_print("Parsing metadata");
+  return readJSONFile(metadata);
+}
+
 function removeCacheFile()
 {
   let file = gProfD.clone();
@@ -138,3 +154,80 @@ function isSubObjectOf(expectedObj, actualObj) {
 // Expand the amount of information available in error logs
 Services.prefs.setBoolPref("browser.search.log", true);
 
+/**
+ * After useHttpServer() is called, this string contains the URL of the "data"
+ * directory, including the final slash.
+ */
+let gDataUrl;
+
+/**
+ * Initializes the HTTP server and ensures that it is terminated when tests end.
+ *
+ * @return The HttpServer object in case further customization is needed.
+ */
+function useHttpServer() {
+  let httpServer = new HttpServer();
+  httpServer.start(-1);
+  httpServer.registerDirectory("/", do_get_cwd());
+  gDataUrl = "http://localhost:" + httpServer.identity.primaryPort + "/data/";
+  do_register_cleanup(() => httpServer.stop(() => {}));
+  return httpServer;
+}
+
+/**
+ * Adds test engines and returns a promise resolved when they are installed.
+ *
+ * The engines are added in the given order.
+ *
+ * @param aItems
+ *        Array of objects with the following properties:
+ *        {
+ *          name: Engine name, used to wait for it to be loaded.
+ *          xmlFileName: Name of the XML file in the "data" folder.
+ *          srcFileName: Name of the SRC file in the "data" folder.
+ *          iconFileName: Name of the icon associated to the SRC file.
+ *          details: Array containing the parameters of addEngineWithDetails,
+ *                   except for the engine name.  Alternative to xmlFileName.
+ *        }
+ */
+let addTestEngines = Task.async(function* (aItems) {
+  if (!gDataUrl) {
+    do_throw("useHttpServer must be called before addTestEngines.");
+  }
+
+  let engines = [];
+
+  for (let item of aItems) {
+    do_print("Adding engine: " + item.name);
+    yield new Promise((resolve, reject) => {
+      Services.obs.addObserver(function obs(subject, topic, data) {
+        try {
+          let engine = subject.QueryInterface(Ci.nsISearchEngine);
+          do_print("Observed " + data + " for " + engine.name);
+          if (data != "engine-added" || engine.name != item.name) {
+            return;
+          }
+
+          Services.obs.removeObserver(obs, "browser-search-engine-modified");
+          engines.push(engine);
+          resolve();
+        } catch (ex) {
+          reject(ex);
+        }
+      }, "browser-search-engine-modified", false);
+
+      if (item.xmlFileName) {
+        Services.search.addEngine(gDataUrl + item.xmlFileName,
+                                  Ci.nsISearchEngine.DATA_XML, null, false);
+      } else if (item.srcFileName) {
+        Services.search.addEngine(gDataUrl + item.srcFileName,
+                                  Ci.nsISearchEngine.DATA_TEXT,
+                                  gDataUrl + item.iconFileName, false);
+      } else {
+        Services.search.addEngineWithDetails(item.name, ...item.details);
+      }
+    });
+  }
+
+  return engines;
+});
diff --git a/toolkit/components/search/tests/xpcshell/test_addEngine_callback.js b/toolkit/components/search/tests/xpcshell/test_addEngine_callback.js
index 22daf16d5f88..25538005813a 100644
--- a/toolkit/components/search/tests/xpcshell/test_addEngine_callback.js
+++ b/toolkit/components/search/tests/xpcshell/test_addEngine_callback.js
@@ -7,12 +7,6 @@
 
 "use strict";
 
-const Ci = Components.interfaces;
-let gHttpServer;
-let gBaseUrl;
-
-Components.utils.import("resource://testing-common/httpd.js");
-
 // Override the prompt service and nsIPrompt, since the search service currently
 // prompts in response to certain installation failures we test here
 // XXX this should disappear once bug 863474 is fixed
@@ -69,7 +63,7 @@ add_test(function simple_callback_test() {
       do_throw("search callback returned error: " + errorCode);
     }
   }
-  Services.search.addEngine(gBaseUrl + "/data/engine.xml",
+  Services.search.addEngine(gDataUrl + "engine.xml",
                             Ci.nsISearchEngine.DATA_XML,
                             null, false, searchCallback);
 });
@@ -87,7 +81,7 @@ add_test(function duplicate_failure_test() {
     }
   }
   // Re-add the same engine added in the previous test
-  Services.search.addEngine(gBaseUrl + "/data/engine.xml",
+  Services.search.addEngine(gDataUrl + "engine.xml",
                             Ci.nsISearchEngine.DATA_XML,
                             null, false, searchCallback);
 });
@@ -112,15 +106,7 @@ add_test(function load_failure_test() {
 
 function run_test() {
   updateAppInfo();
-
-  gHttpServer = new HttpServer();
-  gHttpServer.start(-1);
-  gHttpServer.registerDirectory("/", do_get_cwd());
-  gBaseUrl = "http://localhost:" + gHttpServer.identity.primaryPort;
-
-  do_register_cleanup(function cleanup() {
-    gHttpServer.stop(function() {});
-  });
+  useHttpServer();
 
   run_next_test();
 }
diff --git a/toolkit/components/search/tests/xpcshell/test_defaultEngine.js b/toolkit/components/search/tests/xpcshell/test_defaultEngine.js
index cb8cf7e84aa0..26645fec2642 100644
--- a/toolkit/components/search/tests/xpcshell/test_defaultEngine.js
+++ b/toolkit/components/search/tests/xpcshell/test_defaultEngine.js
@@ -8,40 +8,22 @@
 
 "use strict";
 
-const Ci = Components.interfaces;
+function run_test() {
+  removeMetadata();
+  updateAppInfo();
+  useHttpServer();
 
-Components.utils.import("resource://testing-common/httpd.js");
+  run_next_test();
+}
 
-let waitForEngines = {
-  "Test search engine": 1,
-  "A second test engine": 1
-};
-
-function search_observer(aSubject, aTopic, aData) {
-  let engine = aSubject.QueryInterface(Ci.nsISearchEngine);
-  do_print("Observer: " + aData + " for " + engine.name);
-
-  if (aData != "engine-added") {
-    return;
-  }
-
-  // If the engine is defined in `waitForEngines`, remove it from the list
-  if (waitForEngines[engine.name]) {
-    delete waitForEngines[engine.name];
-  } else {
-    // This engine is not one we're waiting for, so bail out early.
-    return;
-  }
-
-  // Only continue when both engines have been loaded.
-  if (Object.keys(waitForEngines).length)
-    return;
+add_task(function* test_defaultEngine() {
+  let [engine1, engine2] = yield addTestEngines([
+    { name: "Test search engine", xmlFileName: "engine.xml" },
+    { name: "A second test engine", xmlFileName: "engine2.xml" },
+  ]);
 
   let search = Services.search;
 
-  let engine1 = search.getEngineByName("Test search engine");
-  let engine2 = search.getEngineByName("A second test engine");
-
   search.defaultEngine = engine1;
   do_check_eq(search.defaultEngine, engine1);
   search.defaultEngine = engine2
@@ -68,32 +50,4 @@ function search_observer(aSubject, aTopic, aData) {
   do_check_eq(search.defaultEngine, engine1);
   engine2.hidden = false;
   do_check_eq(search.defaultEngine, engine2);
-
-  do_test_finished();
-}
-
-function run_test() {
-  removeMetadata();
-  updateAppInfo();
-
-  let httpServer = new HttpServer();
-  httpServer.start(-1);
-  httpServer.registerDirectory("/", do_get_cwd());
-  let baseUrl = "http://localhost:" + httpServer.identity.primaryPort;
-
-  do_register_cleanup(function cleanup() {
-    httpServer.stop(function() {});
-    Services.obs.removeObserver(search_observer, "browser-search-engine-modified");
-  });
-
-  do_test_pending();
-
-  Services.obs.addObserver(search_observer, "browser-search-engine-modified", false);
-
-  Services.search.addEngine(baseUrl + "/data/engine.xml",
-                            Ci.nsISearchEngine.DATA_XML,
-                            null, false);
-  Services.search.addEngine(baseUrl + "/data/engine2.xml",
-                            Ci.nsISearchEngine.DATA_XML,
-                            null, false);
-}
+});
diff --git a/toolkit/components/search/tests/xpcshell/test_identifiers.js b/toolkit/components/search/tests/xpcshell/test_identifiers.js
index c0d9a985d198..ca4d1e2dba15 100644
--- a/toolkit/components/search/tests/xpcshell/test_identifiers.js
+++ b/toolkit/components/search/tests/xpcshell/test_identifiers.js
@@ -7,7 +7,6 @@
 
 "use strict";
 
-const Ci = Components.interfaces;
 const SEARCH_APP_DIR = 1;
 
 function run_test() {
diff --git a/toolkit/components/search/tests/xpcshell/test_invalid_engine_from_dir.js b/toolkit/components/search/tests/xpcshell/test_invalid_engine_from_dir.js
index 26bd957ae07c..c6455735ac8a 100644
--- a/toolkit/components/search/tests/xpcshell/test_invalid_engine_from_dir.js
+++ b/toolkit/components/search/tests/xpcshell/test_invalid_engine_from_dir.js
@@ -1,8 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-const Ci = Components.interfaces;
-
 /*
  * Test that invalid engine files with xml extensions will not break
  * initialization. See Bug 940446.
diff --git a/toolkit/components/search/tests/xpcshell/test_json_cache.js b/toolkit/components/search/tests/xpcshell/test_json_cache.js
index 96c8067e7691..ea3457ae5642 100644
--- a/toolkit/components/search/tests/xpcshell/test_json_cache.js
+++ b/toolkit/components/search/tests/xpcshell/test_json_cache.js
@@ -7,9 +7,6 @@
 
 "use strict";
 
-const Cc = Components.classes;
-const Ci = Components.interfaces;
-
 // Metadata to write to search-metadata.json for the test.
 let gMetadata = {"[profile]/test-search-engine.xml":{"used":true}};
 
diff --git a/toolkit/components/search/tests/xpcshell/test_multipleIcons.js b/toolkit/components/search/tests/xpcshell/test_multipleIcons.js
index 253ea7f9d026..992a13aa253f 100644
--- a/toolkit/components/search/tests/xpcshell/test_multipleIcons.js
+++ b/toolkit/components/search/tests/xpcshell/test_multipleIcons.js
@@ -7,16 +7,18 @@
 
 "use strict";
 
-const Ci = Components.interfaces;
-const Cu = Components.utils;
+function run_test() {
+  removeMetadata();
+  updateAppInfo();
+  useHttpServer();
 
-Cu.import("resource://testing-common/httpd.js");
+  run_next_test();
+}
 
-  function test_multiIcon() {
-  let engine = Services.search.getEngineByName("IconsTest");
-  do_check_neq(engine, null);
-
-  do_print("Running tests on IconsTest engine");
+add_task(function* test_multipleIcons() {
+  let [engine] = yield addTestEngines([
+    { name: "IconsTest", xmlFileName: "engineImages.xml" },
+  ]);
 
   do_print("The default should be the 16x16 icon");
   do_check_true(engine.iconURI.spec.contains("ico16"));
@@ -44,35 +46,4 @@ Cu.import("resource://testing-common/httpd.js");
   }));
 
   do_test_finished();
-}
-
-function run_test() {
-  removeMetadata();
-  updateAppInfo();
-
-  let httpServer = new HttpServer();
-  httpServer.start(4444);
-  httpServer.registerDirectory("/", do_get_cwd());
-
-  do_register_cleanup(function cleanup() {
-    httpServer.stop(function() {});
-  });
-
-  do_test_pending();
-
-  let observer = function(aSubject, aTopic, aData) {
-    if (aData == "engine-loaded") {
-      test_multiIcon();
-    }
-  };
-
-  Services.obs.addObserver(observer, "browser-search-engine-modified", false);
-
-  do_print("Adding engine with multiple images");
-  Services.search.addEngine("http://localhost:4444/data/engineImages.xml",
-    Ci.nsISearchEngine.DATA_XML, null, false);
-
-  do_timeout(12000, function() {
-    do_throw("Timeout");
-  });
-}
+});
diff --git a/toolkit/components/search/tests/xpcshell/test_nocache.js b/toolkit/components/search/tests/xpcshell/test_nocache.js
index 0b8ce5c6869f..fcb0ee9362a2 100644
--- a/toolkit/components/search/tests/xpcshell/test_nocache.js
+++ b/toolkit/components/search/tests/xpcshell/test_nocache.js
@@ -1,13 +1,6 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
-let Cu = Components.utils;
-let Ci = Components.interfaces;
-
-Cu.import("resource://gre/modules/osfile.jsm");
-Cu.import("resource://gre/modules/Task.jsm");
-Cu.import("resource://testing-common/httpd.js");
-
 /*
  * test_nocache: Start search engine
  * - without search.json
@@ -17,21 +10,19 @@ Cu.import("resource://testing-common/httpd.js");
  * - search.json is created.
  */
 
-
 function run_test()
 {
   removeCache();
   updateAppInfo();
   do_load_manifest("data/chrome.manifest");
+  useHttpServer();
 
-  let httpServer = new HttpServer();
-  httpServer.start(-1);
-  httpServer.registerDirectory("/", do_get_cwd());
+  run_next_test();
+}
 
+add_task(function* test_nocache() {
   let search = Services.search;
 
-  do_test_pending();
-
   // Check that cache is created at startup
   afterCache(function cacheCreated() {
     // Check that search.json has been created.
@@ -39,63 +30,36 @@ function run_test()
     cache.append("search.json");
     do_check_true(cache.exists());
   });
+  yield new Promise((resolve, reject) => search.init(rv => {
+    Components.isSuccessCode(rv) ? resolve() : reject();
+  }));
 
-  // Perform initialization
-  search.init(function ss_initialized(rv) {
-    do_check_true(Components.isSuccessCode(rv));
+  // Add engine and wait for cache update
+  yield addTestEngines([
+    { name: "Test search engine", xmlFileName: "engine.xml" },
+  ]);
 
-    do_print("Setting up observer");
-    function observer(aSubject, aTopic, aData) {
-      do_print("Observing topic " + aTopic);
-      if ("engine-added" == aData) {
-        let engine = search.getEngineByName("Test search engine");
-        if (!engine) {
-          return;
-        }
-        Services.obs.removeObserver(observer, "browser-search-engine-modified");
-        do_print("Engine has been added, let's wait for the cache to be built");
-        afterCache(function() {
-          do_print("Success");
+  do_print("Engine has been added, let's wait for the cache to be built");
+  yield new Promise(resolve => afterCache(resolve));
 
-          Task.spawn(function task() {
-            do_print("Searching test engine in cache");
-            try {
-              let path = OS.Path.join(OS.Constants.Path.profileDir, "search.json");
-              let data = yield OS.File.read(path);
-              let text = new TextDecoder().decode(data);
-              let cache = JSON.parse(text);
-              let found = false;
-              for (let dirName in cache.directories) {
-                for (let engine of cache.directories[dirName].engines) {
-                  if (engine._id == "[app]/test-search-engine.xml") {
-                    found = true;
-                    break;
-                  }
-                }
-                if (found) {
-                  break;
-                }
-              }
-              do_check_true(found);
-            } catch (ex) {
-              do_throw(ex);
-            } finally {
-              removeCache();
-              httpServer.stop(function() {
-                // httpServer doesn't seem to stop cleanly if there is no callback
-              });
-              do_test_finished();
-            }
-          });
-        });
+  do_print("Searching test engine in cache");
+  let path = OS.Path.join(OS.Constants.Path.profileDir, "search.json");
+  let data = yield OS.File.read(path);
+  let text = new TextDecoder().decode(data);
+  let cache = JSON.parse(text);
+  let found = false;
+  for (let dirName in cache.directories) {
+    for (let engine of cache.directories[dirName].engines) {
+      if (engine._id == "[app]/test-search-engine.xml") {
+        found = true;
+        break;
       }
-    };
-    Services.obs.addObserver(observer, "browser-search-engine-modified", false);
+    }
+    if (found) {
+      break;
+    }
+  }
+  do_check_true(found);
 
-    // Add an engine, check if it appears in the cache
-    search.addEngine("http://localhost:" + httpServer.identity.primaryPort +
-                     "/data/engine.xml",
-                     Ci.nsISearchEngine.DATA_XML,
-                     null, false);
-  });
-}
+  removeCache();
+});
diff --git a/toolkit/components/search/tests/xpcshell/test_nodb_pluschanges.js b/toolkit/components/search/tests/xpcshell/test_nodb_pluschanges.js
index 9cccdb38acb6..10d08b22a28c 100644
--- a/toolkit/components/search/tests/xpcshell/test_nodb_pluschanges.js
+++ b/toolkit/components/search/tests/xpcshell/test_nodb_pluschanges.js
@@ -19,90 +19,43 @@
  * and configuration of Firefox.
  */
 
-const Cc = Components.classes;
-const Ci = Components.interfaces;
-const Cu = Components.utils;
-const Cr = Components.results;
-
-Cu.import("resource://testing-common/httpd.js");
-
-
-function run_test()
-{
-  do_print("Preparing test");
+function run_test() {
   removeMetadata();
   updateAppInfo();
   do_load_manifest("data/chrome.manifest");
+  useHttpServer();
 
-  let httpServer = new HttpServer();
-  httpServer.start(-1);
-  httpServer.registerDirectory("/", do_get_cwd());
-  let baseUrl = "http://localhost:" + httpServer.identity.primaryPort;
+  run_next_test();
+}
+
+add_task(function* test_nodb_pluschanges() {
+  let [engine1, engine2] = yield addTestEngines([
+    { name: "Test search engine", xmlFileName: "engine.xml" },
+    { name: "Sherlock test search engine", srcFileName: "engine.src",
+      iconFileName: "ico-size-16x16-png.ico" },
+  ]);
 
   let search = Services.search;
 
-  do_print("Setting up observer");
-  function observer(aSubject, aTopic, aData) {
-    do_print("Observing topic " + aTopic);
-    if ("engine-added" == aData) {
-      let engine1 = search.getEngineByName("Test search engine");
-      let engine2 = search.getEngineByName("Sherlock test search engine");
-      do_print("Currently, engine1 is " + engine1);
-      do_print("Currently, engine2 is " + engine2);
-      if(engine1 && engine2)
-      {
-        search.moveEngine(engine1, 0);
-        search.moveEngine(engine2, 1);
-        do_print("Next step is forcing flush");
-        do_timeout(0,
-                   function() {
-                     do_print("Forcing flush");
-                     // Force flush
-                     // Note: the timeout is needed, to avoid some reentrency
-                     // issues in nsSearchService.
-                     search.QueryInterface(Ci.nsIObserver).
-                       observe(observer, "quit-application", "<no verb>");
-                   });
-        afterCommit(
-          function()
-          {
-            do_print("Commit complete");
-            // Check that search-metadata.json has been created
-            let metadata = gProfD.clone();
-            metadata.append("search-metadata.json");
-            do_check_true(metadata.exists());
+  search.moveEngine(engine1, 0);
+  search.moveEngine(engine2, 1);
 
-            // Check that the entries are placed as specified correctly
-            let stream = NetUtil.newChannel(metadata).open();
-            do_print("Parsing metadata");
-            let json = parseJsonFromStream(stream);
-            do_check_eq(json["[app]/test-search-engine.xml"].order, 1);
-            do_check_eq(json["[profile]/sherlock-test-search-engine.xml"].order, 2);
+  // This is needed to avoid some reentrency issues in nsSearchService.
+  do_print("Next step is forcing flush");
+  yield new Promise(resolve => do_execute_soon(resolve));
 
-            do_print("Cleaning up");
-            httpServer.stop(function() {});
-            stream.close(); // Stream must be closed under Windows
-            removeMetadata();
-            do_test_finished();
-          }
-        );
-      }
-    }
-  };
-  Services.obs.addObserver(observer, "browser-search-engine-modified",
-                           false);
+  do_print("Forcing flush");
+  let promiseCommit = new Promise(resolve => afterCommit(resolve));
+  search.QueryInterface(Ci.nsIObserver)
+        .observe(null, "quit-application", "");
+  yield promiseCommit;
+  do_print("Commit complete");
 
-  do_test_pending();
+  // Check that the entries are placed as specified correctly
+  let json = getSearchMetadata();
+  do_check_eq(json["[app]/test-search-engine.xml"].order, 1);
+  do_check_eq(json["[profile]/sherlock-test-search-engine.xml"].order, 2);
 
-  search.addEngine(baseUrl + "/data/engine.xml",
-                   Ci.nsISearchEngine.DATA_XML,
-                   null, false);
-  search.addEngine(baseUrl + "/data/engine.src",
-                   Ci.nsISearchEngine.DATA_TEXT,
-                   baseUrl + "/data/ico-size-16x16-png.ico",
-                   false);
-
-  do_timeout(120000, function() {
-    do_throw("Timeout");
-  });
-}
+  do_print("Cleaning up");
+  removeMetadata();
+});
diff --git a/toolkit/components/search/tests/xpcshell/test_notifications.js b/toolkit/components/search/tests/xpcshell/test_notifications.js
index e5c18b4b67ad..93e23b43178e 100644
--- a/toolkit/components/search/tests/xpcshell/test_notifications.js
+++ b/toolkit/components/search/tests/xpcshell/test_notifications.js
@@ -3,10 +3,6 @@
 
 "use strict";
 
-const Ci = Components.interfaces;
-
-Components.utils.import("resource://testing-common/httpd.js");
-
 let gTestLog = [];
 
 /**
@@ -62,13 +58,9 @@ function search_observer(subject, topic, data) {
 function run_test() {
   removeMetadata();
   updateAppInfo();
-
-  let httpServer = new HttpServer();
-  httpServer.start(-1);
-  httpServer.registerDirectory("/", do_get_cwd());
+  useHttpServer();
 
   do_register_cleanup(function cleanup() {
-    httpServer.stop(function() {});
     Services.obs.removeObserver(search_observer, "browser-search-engine-modified");
   });
 
@@ -76,9 +68,7 @@ function run_test() {
 
   Services.obs.addObserver(search_observer, "browser-search-engine-modified", false);
 
-  Services.search.addEngine("http://localhost:" +
-                            httpServer.identity.primaryPort +
-                            "/data/engine.xml",
+  Services.search.addEngine(gDataUrl + "engine.xml",
                             Ci.nsISearchEngine.DATA_XML,
                             null, false);
 }
diff --git a/toolkit/components/search/tests/xpcshell/test_prefSync.js b/toolkit/components/search/tests/xpcshell/test_prefSync.js
index 29b4f5001d85..33dc5353a494 100644
--- a/toolkit/components/search/tests/xpcshell/test_prefSync.js
+++ b/toolkit/components/search/tests/xpcshell/test_prefSync.js
@@ -8,15 +8,6 @@
 
 "use strict";
 
-const { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
-
-Cu.import("resource://testing-common/httpd.js");
-
-let waitForEngines = {
-  "Test search engine": 1,
-  "A second test engine": 1
-};
-
 const PREF_BRANCH = "browser.search.";
 
 /**
@@ -35,47 +26,35 @@ function setLocalizedPref(aPrefName, aValue) {
   } catch (ex) {}
 }
 
-function search_observer(aSubject, aTopic, aData) {
-  let engine = aSubject.QueryInterface(Ci.nsISearchEngine);
-  do_print("Observer: " + aData + " for " + engine.name);
+function run_test() {
+  removeMetadata();
+  updateAppInfo();
+  useHttpServer();
 
-  if (aData != "engine-added") {
-    return;
-  }
+  run_next_test();
+}
 
-  // If the engine is defined in `waitForEngines`, remove it from the list
-  if (waitForEngines[engine.name]) {
-    delete waitForEngines[engine.name];
-  } else {
-    // This engine is not one we're waiting for, so bail out early.
-    return;
-  }
-
-  // Only continue when both engines have been loaded.
-  if (Object.keys(waitForEngines).length) {
-    return;
-  }
+add_task(function* test_prefSync() {
+  let [engine1, engine2] = yield addTestEngines([
+    { name: "Test search engine", xmlFileName: "engine.xml" },
+    { name: "A second test engine", xmlFileName: "engine2.xml" },
+  ]);
 
   let search = Services.search;
 
-  let engine1Name = "Test search engine";
-  let engine2Name = "A second test engine";
-  let engine1 = search.getEngineByName(engine1Name);
-  let engine2 = search.getEngineByName(engine2Name);
-
   // Initial sanity check:
   search.defaultEngine = engine1;
   do_check_eq(search.defaultEngine, engine1);
   search.currentEngine = engine1;
   do_check_eq(search.currentEngine, engine1);
 
-  setLocalizedPref("defaultenginename", engine2Name);
+  setLocalizedPref("defaultenginename", engine2.name);
   // Default engine should be synced with the pref
   do_check_eq(search.defaultEngine, engine2);
   // Current engine should've stayed the same
   do_check_eq(search.currentEngine, engine1);
   
-  setLocalizedPref("selectedEngine", engine2Name);
+  setLocalizedPref("selectedEngine", engine2.name);
   // Default engine should've stayed the same
   do_check_eq(search.defaultEngine, engine2);
   // Current engine should've been updated
@@ -86,7 +65,7 @@ function search_observer(aSubject, aTopic, aData) {
   // set the value of defaultenginename on the default branch.
   let defaultBranch = Services.prefs.getDefaultBranch("");
   let prefName = PREF_BRANCH + "defaultenginename";
-  let prefVal = "data:text/plain," + prefName + "=" + engine1Name;
+  let prefVal = "data:text/plain," + prefName + "=" + engine1.name;
   defaultBranch.setCharPref(prefName, prefVal, true);
   search.currentEngine = engine1;
   // Current engine should've been updated
@@ -99,32 +78,4 @@ function search_observer(aSubject, aTopic, aData) {
   search.defaultEngine = engine1;
   do_check_eq(search.defaultEngine, engine1);
   do_check_false(Services.prefs.prefHasUserValue("browser.search.defaultenginename"));
-
-  do_test_finished();
-}
-
-function run_test() {
-  removeMetadata();
-  updateAppInfo();
-
-  let httpServer = new HttpServer();
-  httpServer.start(-1);
-  httpServer.registerDirectory("/", do_get_cwd());
-  let baseUrl = "http://localhost:" + httpServer.identity.primaryPort;
-
-  do_register_cleanup(function cleanup() {
-    httpServer.stop(function() {});
-    Services.obs.removeObserver(search_observer, "browser-search-engine-modified");
-  });
-
-  do_test_pending();
-
-  Services.obs.addObserver(search_observer, "browser-search-engine-modified", false);
-
-  Services.search.addEngine(baseUrl + "/data/engine.xml",
-                   Ci.nsISearchEngine.DATA_XML,
-                   null, false);
-  Services.search.addEngine(baseUrl + "/data/engine2.xml",
-                   Ci.nsISearchEngine.DATA_XML,
-                   null, false);
-}
+});
diff --git a/toolkit/components/search/tests/xpcshell/test_purpose.js b/toolkit/components/search/tests/xpcshell/test_purpose.js
index 256ca21dae66..107e9fbb8127 100644
--- a/toolkit/components/search/tests/xpcshell/test_purpose.js
+++ b/toolkit/components/search/tests/xpcshell/test_purpose.js
@@ -8,19 +8,19 @@
 
 "use strict";
 
-const Ci = Components.interfaces;
+function run_test() {
+  removeMetadata();
+  updateAppInfo();
+  do_load_manifest("data/chrome.manifest");
+  useHttpServer();
 
-Components.utils.import("resource://testing-common/httpd.js");
+  run_next_test();
+}
 
-function search_observer(aSubject, aTopic, aData) {
-  let engine = aSubject.QueryInterface(Ci.nsISearchEngine);
-  do_print("Observer: " + aData + " for " + engine.name);
-
-  if (aData != "engine-added")
-    return;
-
-  if (engine.name != "Test search engine")
-    return;
+add_task(function* test_purpose() {
+  let [engine] = yield addTestEngines([
+    { name: "Test search engine", xmlFileName: "engine.xml" },
+  ]);
 
   function check_submission(aExpected, aSearchTerm, aType, aPurpose) {
     do_check_eq(engine.getSubmission(aSearchTerm, aType, aPurpose).uri.spec,
@@ -47,28 +47,4 @@ function search_observer(aSubject, aTopic, aData) {
   check_submission("",              "foo", "application/x-moz-default-purpose", "invalid");
 
   do_test_finished();
-};
-
-function run_test() {
-  removeMetadata();
-  updateAppInfo();
-  do_load_manifest("data/chrome.manifest");
-
-  let httpServer = new HttpServer();
-  httpServer.start(-1);
-  httpServer.registerDirectory("/", do_get_cwd());
-
-  do_register_cleanup(function cleanup() {
-    httpServer.stop(function() {});
-    Services.obs.removeObserver(search_observer, "browser-search-engine-modified");
-  });
-
-  do_test_pending();
-  Services.obs.addObserver(search_observer, "browser-search-engine-modified", false);
-
-  Services.search.addEngine("http://localhost:" +
-                            httpServer.identity.primaryPort +
-                            "/data/engine.xml",
-                            Ci.nsISearchEngine.DATA_XML,
-                            null, false);
-}
+});
diff --git a/toolkit/components/search/tests/xpcshell/test_rel_searchform.js b/toolkit/components/search/tests/xpcshell/test_rel_searchform.js
index c9918a320d54..e49ae47b1b05 100644
--- a/toolkit/components/search/tests/xpcshell/test_rel_searchform.js
+++ b/toolkit/components/search/tests/xpcshell/test_rel_searchform.js
@@ -7,60 +7,27 @@
 
 "use strict";
 
-const Ci = Components.interfaces;
+function run_test() {
+  removeMetadata();
+  updateAppInfo();
+  useHttpServer();
 
-Components.utils.import("resource://testing-common/httpd.js");
+  run_next_test();
+}
 
-let engines = [
-  "engine-rel-searchform.xml",
-  "engine-rel-searchform-post.xml",
-];
-
-function search_observer(aSubject, aTopic, aData) {
-  let engine = aSubject.QueryInterface(Ci.nsISearchEngine);
-  do_print("Observer: " + aData + " for " + engine.name);
-
-  if (aData != "engine-added")
-    return;
-
-  let idx = engines.indexOf(engine.name);
-  if (idx < 0)
-    // The engine is some other engine unrelated to the test, so ignore it.
-    return;
+add_task(function* test_rel_searchform() {
+  let engineNames = [
+    "engine-rel-searchform.xml",
+    "engine-rel-searchform-post.xml",
+  ];
 
   // The final searchForm of the engine should be a URL whose domain is the
   // <ShortName> in the engine's XML and that has a ?search parameter.  The
   // point of the ?search parameter is to avoid accidentally matching the value
   // returned as a last resort by Engine's searchForm getter, which is simply
   // the prePath of the engine's first HTML <Url>.
-  do_check_eq(engine.searchForm, "http://" + engine.name + "/?search");
-
-  engines.splice(idx, 1);
-  if (!engines.length)
-    do_test_finished();
-}
-
-function run_test() {
-  removeMetadata();
-  updateAppInfo();
-
-  let httpServer = new HttpServer();
-  httpServer.start(-1);
-  httpServer.registerDirectory("/", do_get_cwd());
-
-  do_register_cleanup(function cleanup() {
-    httpServer.stop(function() {});
-    Services.obs.removeObserver(search_observer, "browser-search-engine-modified");
-  });
-
-  do_test_pending();
-  Services.obs.addObserver(search_observer, "browser-search-engine-modified", false);
-
-  for (let basename of engines) {
-    Services.search.addEngine("http://localhost:" +
-                              httpServer.identity.primaryPort +
-                              "/data/" + basename,
-                              Ci.nsISearchEngine.DATA_XML,
-                              null, false);
+  let items = [for (e of engineNames) { name: e, xmlFileName: e }];
+  for (let engine of yield addTestEngines(items)) {
+    do_check_eq(engine.searchForm, "http://" + engine.name + "/?search");
   }
-}
+});
diff --git a/toolkit/components/search/tests/xpcshell/test_resultDomain.js b/toolkit/components/search/tests/xpcshell/test_resultDomain.js
index ff3a4fecac7c..d7458a923f6e 100644
--- a/toolkit/components/search/tests/xpcshell/test_resultDomain.js
+++ b/toolkit/components/search/tests/xpcshell/test_resultDomain.js
@@ -7,73 +7,27 @@
 
 "use strict";
 
-const Ci = Components.interfaces;
-
-Components.utils.import("resource://testing-common/httpd.js");
-
-let waitForEngines = new Set([ "Test search engine",
-                               "A second test engine",
-                               "bacon" ]);
-
-function promiseEnginesAdded() {
-  let deferred = Promise.defer();
-
-  let observe = function observe(aSubject, aTopic, aData) {
-    let engine = aSubject.QueryInterface(Ci.nsISearchEngine);
-    do_print("Observer: " + aData + " for " + engine.name);
-    if (aData != "engine-added") {
-      return;
-    }
-    waitForEngines.delete(engine.name);
-    if (waitForEngines.size > 0) {
-      return;
-    }
-
-    let engine1 = Services.search.getEngineByName("Test search engine");
-    do_check_eq(engine1.getResultDomain(), "google.com");
-    do_check_eq(engine1.getResultDomain("text/html"), "google.com");
-    do_check_eq(engine1.getResultDomain("application/x-moz-default-purpose"),
-                "purpose.google.com");
-    do_check_eq(engine1.getResultDomain("fake-response-type"), "");
-    let engine2 = Services.search.getEngineByName("A second test engine");
-    do_check_eq(engine2.getResultDomain(), "duckduckgo.com");
-    let engine3 = Services.search.getEngineByName("bacon");
-    do_check_eq(engine3.getResultDomain(), "bacon.moz");
-    deferred.resolve();
-  };
-
-  Services.obs.addObserver(observe, "browser-search-engine-modified", false);
-  do_register_cleanup(function cleanup() {
-    Services.obs.removeObserver(observe, "browser-search-engine-modified");
-  });
-
-  return deferred.promise;
-}
-
 function run_test() {
   removeMetadata();
   updateAppInfo();
+  useHttpServer();
 
   run_next_test();
 }
 
-add_task(function* check_resultDomain() {
-  let httpServer = new HttpServer();
-  httpServer.start(-1);
-  httpServer.registerDirectory("/", do_get_cwd());
-  let baseUrl = "http://localhost:" + httpServer.identity.primaryPort;
-  do_register_cleanup(function cleanup() {
-    httpServer.stop(function() {});
-  });
+add_task(function* test_resultDomain() {
+  let [engine1, engine2, engine3] = yield addTestEngines([
+    { name: "Test search engine", xmlFileName: "engine.xml" },
+    { name: "A second test engine", xmlFileName: "engine2.xml" },
+    { name: "bacon", details: ["", "bacon", "Search Bacon", "GET",
+                               "http://www.bacon.moz/?search={searchTerms}"] },
+  ]);
 
-  let promise = promiseEnginesAdded();
-  Services.search.addEngine(baseUrl + "/data/engine.xml",
-                            Ci.nsISearchEngine.DATA_XML,
-                            null, false);
-  Services.search.addEngine(baseUrl + "/data/engine2.xml",
-                            Ci.nsISearchEngine.DATA_XML,
-                            null, false);
-  Services.search.addEngineWithDetails("bacon", "", "bacon", "Search Bacon",
-                                       "GET", "http://www.bacon.moz/?search={searchTerms}");
-  yield promise;
+  do_check_eq(engine1.getResultDomain(), "google.com");
+  do_check_eq(engine1.getResultDomain("text/html"), "google.com");
+  do_check_eq(engine1.getResultDomain("application/x-moz-default-purpose"),
+              "purpose.google.com");
+  do_check_eq(engine1.getResultDomain("fake-response-type"), "");
+  do_check_eq(engine2.getResultDomain(), "duckduckgo.com");
+  do_check_eq(engine3.getResultDomain(), "bacon.moz");
 });
diff --git a/toolkit/components/search/tests/xpcshell/test_save_sorted_engines.js b/toolkit/components/search/tests/xpcshell/test_save_sorted_engines.js
index cd2ee8e8a261..05149cd73194 100644
--- a/toolkit/components/search/tests/xpcshell/test_save_sorted_engines.js
+++ b/toolkit/components/search/tests/xpcshell/test_save_sorted_engines.js
@@ -17,108 +17,55 @@
  * and configuration of Firefox.
  */
 
-const Cc = Components.classes;
-const Ci = Components.interfaces;
-const Cu = Components.utils;
-const Cr = Components.results;
-
-Cu.import("resource://testing-common/httpd.js");
-
 function run_test() {
-  do_print("Preparing test");
   removeMetadata();
   updateAppInfo();
+  useHttpServer();
 
-  let httpServer = new HttpServer();
-  httpServer.start(-1);
-  httpServer.registerDirectory("/", do_get_cwd());
-  let baseUrl = "http://localhost:" + httpServer.identity.primaryPort;
+  run_next_test();
+}
 
-  function getSearchMetadata() {
-    // Check that search-metadata.json has been created
-    let metadata = gProfD.clone();
-    metadata.append("search-metadata.json");
-    do_check_true(metadata.exists());
-
-    let stream = NetUtil.newChannel(metadata).open();
-    do_print("Parsing metadata");
-    let json = parseJsonFromStream(stream);
-    stream.close(); // Stream must be closed under Windows
-
-    return json;
-  }
+add_task(function* test_save_sorted_engines() {
+  let [engine1, engine2] = yield addTestEngines([
+    { name: "Test search engine", xmlFileName: "engine.xml" },
+    { name: "Sherlock test search engine", srcFileName: "engine.src",
+      iconFileName: "ico-size-16x16-png.ico" },
+  ]);
 
   let search = Services.search;
 
-  do_print("Setting up observer");
-  function observer(aSubject, aTopic, aData) {
-    do_print("Observing topic " + aTopic);
-    if ("engine-added" != aData) {
-      return;
-    }
+  // Test moving the engines
+  search.moveEngine(engine1, 0);
+  search.moveEngine(engine2, 1);
 
-    let engine1 = search.getEngineByName("Test search engine");
-    let engine2 = search.getEngineByName("Sherlock test search engine");
-    do_print("Currently, engine1 is " + engine1);
-    do_print("Currently, engine2 is " + engine2);
-    if (!engine1 || !engine2) {
-      return;
-    }
+  // Changes should be commited immediately
+  yield new Promise(resolve => afterCommit(resolve));
+  do_print("Commit complete after moveEngine");
 
-    // Test moving the engines
-    search.moveEngine(engine1, 0);
-    search.moveEngine(engine2, 1);
+  // Check that the entries are placed as specified correctly
+  let json = getSearchMetadata();
+  do_check_eq(json["[app]/test-search-engine.xml"].order, 1);
+  do_check_eq(json["[profile]/sherlock-test-search-engine.xml"].order, 2);
 
-    // Changes should be commited immediately
-    afterCommit(function() {
-      do_print("Commit complete after moveEngine");
+  // Test removing an engine
+  search.removeEngine(engine1);
+  yield new Promise(resolve => afterCommit(resolve));
+  do_print("Commit complete after removeEngine");
 
-      // Check that the entries are placed as specified correctly
-      let json = getSearchMetadata();
-      do_check_eq(json["[app]/test-search-engine.xml"].order, 1);
-      do_check_eq(json["[profile]/sherlock-test-search-engine.xml"].order, 2);
+  // Check that the order of the remaining engine was updated correctly
+  json = getSearchMetadata();
+  do_check_eq(json["[profile]/sherlock-test-search-engine.xml"].order, 1);
 
-      // Test removing an engine
-      search.removeEngine(engine1);
-      afterCommit(function() {
-        do_print("Commit complete after removeEngine");
+  // Test adding a new engine
+  search.addEngineWithDetails("foo", "", "foo", "", "GET",
+                              "http://searchget/?search={searchTerms}");
+  yield new Promise(resolve => afterCommit(resolve));
+  do_print("Commit complete after addEngineWithDetails");
 
-        // Check that the order of the remaining engine was updated correctly
-        let json = getSearchMetadata();
-        do_check_eq(json["[profile]/sherlock-test-search-engine.xml"].order, 1);
+  json = getSearchMetadata();
+  do_check_eq(json["[profile]/foo.xml"].alias, "foo");
+  do_check_true(json["[profile]/foo.xml"].order > 0);
 
-        // Test adding a new engine
-        search.addEngineWithDetails("foo", "", "foo", "", "GET", "http://searchget/?search={searchTerms}");
-        afterCommit(function() {
-          do_print("Commit complete after addEngineWithDetails");
-
-          // Check that engine was added to the list of sorted engines
-          let json = getSearchMetadata();
-          do_check_eq(json["[profile]/foo.xml"].alias, "foo");
-          do_check_true(json["[profile]/foo.xml"].order > 0);
-
-          do_print("Cleaning up");
-          Services.obs.removeObserver(observer, "browser-search-engine-modified");
-          httpServer.stop(function() {});
-          removeMetadata();
-          do_test_finished();
-        });
-      });
-    });
-  };
-  Services.obs.addObserver(observer, "browser-search-engine-modified", false);
-
-  do_test_pending();
-
-  search.addEngine(baseUrl + "/data/engine.xml",
-                   Ci.nsISearchEngine.DATA_XML,
-                   null, false);
-  search.addEngine(baseUrl + "/data/engine.src",
-                   Ci.nsISearchEngine.DATA_TEXT,
-                   baseUrl + "/data/ico-size-16x16-png.ico",
-                   false);
-
-  do_timeout(120000, function() {
-    do_throw("Timeout");
-  });
-}
+  do_print("Cleaning up");
+  removeMetadata();
+});
diff --git a/toolkit/components/search/tests/xpcshell/test_serialize_file.js b/toolkit/components/search/tests/xpcshell/test_serialize_file.js
index 84cf289be1ad..e999bfcdca06 100644
--- a/toolkit/components/search/tests/xpcshell/test_serialize_file.js
+++ b/toolkit/components/search/tests/xpcshell/test_serialize_file.js
@@ -10,38 +10,27 @@
  * - lazySerializeTask updates the file.
  */
 
-const Ci = Components.interfaces;
-const Cu = Components.utils;
+function run_test() {
+  updateAppInfo();
+  useHttpServer();
 
-Cu.import("resource://testing-common/httpd.js");
-Cu.import("resource://gre/modules/NetUtil.jsm");
+  run_next_test();
+}
 
-add_test(function test_batchTask() {
-  let observer = function(aSubject, aTopic, aData) {
-    if (aTopic == "browser-search-engine-modified" && aData == "engine-loaded") {
-      let engine1 = Services.search.getEngineByName("Test search engine");
-      let engine2 = Services.search.getEngineByName("Sherlock test search engine");
-      if (engine1 && engine2) {
-        Services.obs.removeObserver(observer, aTopic);
-        // Test that files are written correctly.
-        let engineFile1 = engine1.wrappedJSObject._file;
-        let engineFile2 = engine2.wrappedJSObject._file;
-        do_check_true(engineFile1.exists());
-        do_check_true(engineFile2.exists());
-        do_check_neq(engineFile1.fileSize, 0);
-        do_check_neq(engineFile2.fileSize, 0);
-        run_next_test();
-      }
-    }
-  }
+add_task(function test_batchTask() {
+  let [engine1, engine2] = yield addTestEngines([
+    { name: "Test search engine", xmlFileName: "engine.xml" },
+    { name: "Sherlock test search engine", srcFileName: "engine.src",
+      iconFileName: "ico-size-16x16-png.ico" },
+  ]);
 
-  Services.obs.addObserver(observer, "browser-search-engine-modified", false);
-  Services.search.addEngine("http://localhost:4444/data/engine.xml",
-                            Ci.nsISearchEngine.DATA_XML, null, false);
-  Services.search.addEngine("http://localhost:4444/data/engine.src",
-                            Ci.nsISearchEngine.DATA_TEXT,
-                            "http://localhost:4444/data/ico-size-16x16-png.ico",
-                            false);
+  // Test that files are written correctly.
+  let engineFile1 = engine1.wrappedJSObject._file;
+  let engineFile2 = engine2.wrappedJSObject._file;
+  do_check_true(engineFile1.exists());
+  do_check_true(engineFile2.exists());
+  do_check_neq(engineFile1.fileSize, 0);
+  do_check_neq(engineFile2.fileSize, 0);
 });
 
 add_test(function test_addParam() {
@@ -76,17 +65,3 @@ add_test(function test_addParam() {
   }
   Services.obs.addObserver(observer, "browser-search-service", false);
 });
-
-function run_test() {
-  updateAppInfo();
-
-  let httpServer = new HttpServer();
-  httpServer.start(4444);
-  httpServer.registerDirectory("/", do_get_cwd());
-
-  do_register_cleanup(function cleanup() {
-    httpServer.stop(function() {});
-  });
-
-  run_next_test();
-}