1 files changed, 240 insertions, 0 deletions
diff --git a/toolkit/modules/tests/xpcshell/test_Integration.js b/toolkit/modules/tests/xpcshell/test_Integration.js
new file mode 100644
index 0000000000..8213e32592
--- /dev/null
+++ b/toolkit/modules/tests/xpcshell/test_Integration.js
@@ -0,0 +1,240 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/*
+ * Tests the Integration.sys.mjs module.
+ */
+
+"use strict";
+const { Integration } = ChromeUtils.importESModule(
+  "resource://gre/modules/Integration.sys.mjs"
+);
+
+const TestIntegration = {
+  value: "value",
+
+  get valueFromThis() {
+    return this.value;
+  },
+
+  get property() {
+    return this._property;
+  },
+
+  set property(value) {
+    this._property = value;
+  },
+
+  method(argument) {
+    this.methodArgument = argument;
+    return "method" + argument;
+  },
+
+  async asyncMethod(argument) {
+    this.asyncMethodArgument = argument;
+    return "asyncMethod" + argument;
+  },
+};
+
+let overrideFn = base => ({
+  value: "overridden-value",
+
+  get property() {
+    return "overridden-" + base.__lookupGetter__("property").call(this);
+  },
+
+  set property(value) {
+    base.__lookupSetter__("property").call(this, "overridden-" + value);
+  },
+
+  method() {
+    return "overridden-" + base.method.apply(this, arguments);
+  },
+
+  async asyncMethod() {
+    return "overridden-" + (await base.asyncMethod.apply(this, arguments));
+  },
+});
+
+let superOverrideFn = base => {
+  let nextLevel = {
+    value: "overridden-value",
+
+    get property() {
+      return "overridden-" + super.property;
+    },
+
+    set property(value) {
+      super.property = "overridden-" + value;
+    },
+
+    method() {
+      return "overridden-" + super.method(...arguments);
+    },
+
+    async asyncMethod() {
+      // We cannot use the "super" keyword in methods defined using "Task.async".
+      return "overridden-" + (await base.asyncMethod.apply(this, arguments));
+    },
+  };
+  Object.setPrototypeOf(nextLevel, base);
+  return nextLevel;
+};
+
+/**
+ * Fails the test if the results of method invocations on the combined object
+ * don't match the expected results based on how many overrides are registered.
+ *
+ * @param combined
+ *        The combined object based on the TestIntegration root.
+ * @param overridesCount
+ *        Zero if the root object is not overridden, or a higher value to test
+ *        the presence of one or more integration overrides.
+ */
+async function assertCombinedResults(combined, overridesCount) {
+  let expectedValue = overridesCount > 0 ? "overridden-value" : "value";
+  let prefix = "overridden-".repeat(overridesCount);
+
+  Assert.equal(combined.value, expectedValue);
+  Assert.equal(combined.valueFromThis, expectedValue);
+
+  combined.property = "property";
+  Assert.equal(combined.property, prefix.repeat(2) + "property");
+
+  combined.methodArgument = "";
+  Assert.equal(combined.method("-argument"), prefix + "method-argument");
+  Assert.equal(combined.methodArgument, "-argument");
+
+  combined.asyncMethodArgument = "";
+  Assert.equal(
+    await combined.asyncMethod("-argument"),
+    prefix + "asyncMethod-argument"
+  );
+  Assert.equal(combined.asyncMethodArgument, "-argument");
+}
+
+/**
+ * Fails the test if the results of method invocations on the combined object
+ * for the "testModule" integration point don't match the expected results based
+ * on how many overrides are registered.
+ *
+ * @param overridesCount
+ *        Zero if the root object is not overridden, or a higher value to test
+ *        the presence of one or more integration overrides.
+ */
+async function assertCurrentCombinedResults(overridesCount) {
+  let combined = Integration.testModule.getCombined(TestIntegration);
+  await assertCombinedResults(combined, overridesCount);
+}
+
+/**
+ * Checks the initial state with no integration override functions registered.
+ */
+add_task(async function test_base() {
+  await assertCurrentCombinedResults(0);
+});
+
+/**
+ * Registers and unregisters an integration override function.
+ */
+add_task(async function test_override() {
+  Integration.testModule.register(overrideFn);
+  await assertCurrentCombinedResults(1);
+
+  // Registering the same function more than once has no effect.
+  Integration.testModule.register(overrideFn);
+  await assertCurrentCombinedResults(1);
+
+  Integration.testModule.unregister(overrideFn);
+  await assertCurrentCombinedResults(0);
+});
+
+/**
+ * Registers and unregisters more than one integration override function, of
+ * which one uses the prototype and the "super" keyword to access the base.
+ */
+add_task(async function test_override_super_multiple() {
+  Integration.testModule.register(overrideFn);
+  Integration.testModule.register(superOverrideFn);
+  await assertCurrentCombinedResults(2);
+
+  Integration.testModule.unregister(overrideFn);
+  await assertCurrentCombinedResults(1);
+
+  Integration.testModule.unregister(superOverrideFn);
+  await assertCurrentCombinedResults(0);
+});
+
+/**
+ * Registers an integration override function that throws an exception, and
+ * ensures that this does not block other functions from being registered.
+ */
+add_task(async function test_override_error() {
+  let errorOverrideFn = base => {
+    throw new Error("Expected error.");
+  };
+
+  Integration.testModule.register(errorOverrideFn);
+  Integration.testModule.register(overrideFn);
+  await assertCurrentCombinedResults(1);
+
+  Integration.testModule.unregister(errorOverrideFn);
+  Integration.testModule.unregister(overrideFn);
+  await assertCurrentCombinedResults(0);
+});
+
+/**
+ * Checks that state saved using the "this" reference is preserved as a shallow
+ * copy when registering new integration override functions.
+ */
+add_task(async function test_state_preserved() {
+  let valueObject = { toString: () => "toString" };
+
+  let combined = Integration.testModule.getCombined(TestIntegration);
+  combined.property = valueObject;
+  Assert.ok(combined.property === valueObject);
+
+  Integration.testModule.register(overrideFn);
+  combined = Integration.testModule.getCombined(TestIntegration);
+  Assert.equal(combined.property, "overridden-toString");
+
+  Integration.testModule.unregister(overrideFn);
+  combined = Integration.testModule.getCombined(TestIntegration);
+  Assert.ok(combined.property === valueObject);
+});
+
+/**
+ * Checks that the combined integration objects cannot be used with XPCOM.
+ *
+ * This is limited by the fact that interfaces with the "[function]" annotation,
+ * for example nsIObserver, do not call the QueryInterface implementation.
+ */
+add_task(async function test_xpcom_throws() {
+  let combined = Integration.testModule.getCombined(TestIntegration);
+
+  // This calls QueryInterface because it looks for nsISupportsWeakReference.
+  Assert.throws(
+    () => Services.obs.addObserver(combined, "test-topic", true),
+    /NS_NOINTERFACE/
+  );
+});
+
+/**
+ * Checks that getters defined by defineESModuleGetter are able to retrieve the
+ * latest version of the combined integration object.
+ */
+add_task(async function test_defineESModuleGetter() {
+  let objectForGetters = {};
+
+  Integration.testModule.defineESModuleGetter(
+    objectForGetters,
+    "TestIntegration",
+    "resource://testing-common/TestIntegration.sys.mjs"
+  );
+
+  Integration.testModule.register(overrideFn);
+  await assertCombinedResults(objectForGetters.TestIntegration, 1);
+
+  Integration.testModule.unregister(overrideFn);
+  await assertCombinedResults(objectForGetters.TestIntegration, 0);
+});