1 files changed, 72 insertions, 0 deletions
diff --git a/devtools/client/performance/test/helpers/prefs.js b/devtools/client/performance/test/helpers/prefs.js
new file mode 100644
index 000000000..4d17afe12
--- /dev/null
+++ b/devtools/client/performance/test/helpers/prefs.js
@@ -0,0 +1,72 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+const Services = require("Services");
+const { Preferences } = require("resource://gre/modules/Preferences.jsm");
+
+// Prefs to revert to default once tests finish. Keep these in sync with
+// all the preferences defined in devtools/client/preferences/devtools.js.
+exports.MEMORY_SAMPLE_PROB_PREF = "devtools.performance.memory.sample-probability";
+exports.MEMORY_MAX_LOG_LEN_PREF = "devtools.performance.memory.max-log-length";
+exports.PROFILER_BUFFER_SIZE_PREF = "devtools.performance.profiler.buffer-size";
+exports.PROFILER_SAMPLE_RATE_PREF = "devtools.performance.profiler.sample-frequency-khz";
+
+exports.UI_EXPERIMENTAL_PREF = "devtools.performance.ui.experimental";
+exports.UI_INVERT_CALL_TREE_PREF = "devtools.performance.ui.invert-call-tree";
+exports.UI_INVERT_FLAME_PREF = "devtools.performance.ui.invert-flame-graph";
+exports.UI_FLATTEN_RECURSION_PREF = "devtools.performance.ui.flatten-tree-recursion";
+exports.UI_SHOW_PLATFORM_DATA_PREF = "devtools.performance.ui.show-platform-data";
+exports.UI_SHOW_IDLE_BLOCKS_PREF = "devtools.performance.ui.show-idle-blocks";
+exports.UI_ENABLE_FRAMERATE_PREF = "devtools.performance.ui.enable-framerate";
+exports.UI_ENABLE_MEMORY_PREF = "devtools.performance.ui.enable-memory";
+exports.UI_ENABLE_ALLOCATIONS_PREF = "devtools.performance.ui.enable-allocations";
+exports.UI_ENABLE_MEMORY_FLAME_CHART = "devtools.performance.ui.enable-memory-flame";
+
+exports.DEFAULT_PREF_VALUES = [
+  "devtools.debugger.log",
+  "devtools.performance.enabled",
+  "devtools.performance.timeline.hidden-markers",
+  exports.MEMORY_SAMPLE_PROB_PREF,
+  exports.MEMORY_MAX_LOG_LEN_PREF,
+  exports.PROFILER_BUFFER_SIZE_PREF,
+  exports.PROFILER_SAMPLE_RATE_PREF,
+  exports.UI_EXPERIMENTAL_PREF,
+  exports.UI_INVERT_CALL_TREE_PREF,
+  exports.UI_INVERT_FLAME_PREF,
+  exports.UI_FLATTEN_RECURSION_PREF,
+  exports.UI_SHOW_PLATFORM_DATA_PREF,
+  exports.UI_SHOW_IDLE_BLOCKS_PREF,
+  exports.UI_ENABLE_FRAMERATE_PREF,
+  exports.UI_ENABLE_MEMORY_PREF,
+  exports.UI_ENABLE_ALLOCATIONS_PREF,
+  exports.UI_ENABLE_MEMORY_FLAME_CHART,
+  "devtools.performance.ui.show-jit-optimizations",
+  "devtools.performance.ui.show-triggers-for-gc-types",
+].reduce((prefValues, prefName) => {
+  prefValues[prefName] = Preferences.get(prefName);
+  return prefValues;
+}, {});
+
+/**
+ * Invokes callback when a pref which is not in the `DEFAULT_PREF_VALUES` store
+ * is changed. Returns a cleanup function.
+ */
+exports.whenUnknownPrefChanged = function (branch, callback) {
+  function onObserve(subject, topic, data) {
+    if (!(data in exports.DEFAULT_PREF_VALUES)) {
+      callback(data);
+    }
+  }
+  Services.prefs.addObserver(branch, onObserve, false);
+  return () => Services.prefs.removeObserver(branch, onObserve);
+};
+
+/**
+ * Reverts all known preferences to their default values.
+ */
+exports.rollbackPrefsToDefault = function () {
+  for (let prefName of Object.keys(exports.DEFAULT_PREF_VALUES)) {
+    Preferences.set(prefName, exports.DEFAULT_PREF_VALUES[prefName]);
+  }
+};