1 files changed, 161 insertions, 0 deletions
diff --git a/devtools/client/shared/test/browser_browserloader_mocks.js b/devtools/client/shared/test/browser_browserloader_mocks.js
new file mode 100644
index 0000000000..2ed67eb144
--- /dev/null
+++ b/devtools/client/shared/test/browser_browserloader_mocks.js
@@ -0,0 +1,161 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { BrowserLoader } = ChromeUtils.import(
+  "resource://devtools/shared/loader/browser-loader.js"
+);
+
+const {
+  getMockedModule,
+  setMockedModule,
+  removeMockedModule,
+} = require("resource://devtools/shared/loader/browser-loader-mocks.js");
+const { require: browserRequire } = BrowserLoader({
+  baseURI: "resource://devtools/client/shared/",
+  window,
+});
+
+// Check that modules can be mocked in the browser loader.
+// Test with a custom test module under the chrome:// scheme.
+function testWithChromeScheme() {
+  // Full chrome URI for the test module.
+  const CHROME_URI = CHROME_URL_ROOT + "test-mocked-module.js";
+  const ORIGINAL_VALUE = "Original value";
+  const MOCKED_VALUE_1 = "Mocked value 1";
+  const MOCKED_VALUE_2 = "Mocked value 2";
+
+  const m1 = browserRequire(CHROME_URI);
+  ok(m1, "Regular module can be required");
+  is(m1.methodToMock(), ORIGINAL_VALUE, "Method returns the expected value");
+  is(m1.someProperty, "someProperty", "Property has the expected value");
+
+  info("Create a simple mocked version of the test module");
+  const mockedModule = {
+    methodToMock: () => MOCKED_VALUE_1,
+    someProperty: "somePropertyMocked",
+  };
+  setMockedModule(mockedModule, CHROME_URI);
+  ok(!!getMockedModule(CHROME_URI), "Has an entry for the chrome URI.");
+
+  const m2 = browserRequire(CHROME_URI);
+  ok(m2, "Mocked module can be required via chrome URI");
+  is(
+    m2.methodToMock(),
+    MOCKED_VALUE_1,
+    "Mocked method returns the expected value"
+  );
+  is(
+    m2.someProperty,
+    "somePropertyMocked",
+    "Mocked property has the expected value"
+  );
+
+  const { methodToMock: requiredMethod } = browserRequire(CHROME_URI);
+  ok(
+    requiredMethod() === MOCKED_VALUE_1,
+    "Mocked method returns the expected value when imported with destructuring"
+  );
+
+  info("Update the mocked method to return a different value");
+  mockedModule.methodToMock = () => MOCKED_VALUE_2;
+  is(
+    requiredMethod(),
+    MOCKED_VALUE_2,
+    "Mocked method returns the updated value  when imported with destructuring"
+  );
+
+  info("Remove the mock for the test module");
+  removeMockedModule(CHROME_URI);
+  ok(!getMockedModule(CHROME_URI), "Has no entry for the chrome URI.");
+
+  const m3 = browserRequire(CHROME_URI);
+  ok(m3, "Regular module can be required after removing the mock");
+  is(
+    m3.methodToMock(),
+    ORIGINAL_VALUE,
+    "Method on module returns the expected value"
+  );
+}
+
+// Similar tests as in testWithChromeScheme, but this time with a devtools module
+// available under the resource:// scheme.
+function testWithRegularDevtoolsModule() {
+  // Testing with devtools/shared/path because it is a simple module, that can be imported
+  // with destructuring. Any other module would do.
+  const DEVTOOLS_MODULE_PATH = "devtools/shared/path";
+  const DEVTOOLS_MODULE_URI = "resource://devtools/shared/path.js";
+
+  const m1 = browserRequire(DEVTOOLS_MODULE_PATH);
+  is(
+    m1.joinURI("https://a", "b"),
+    "https://a/b",
+    "Original module was required"
+  );
+
+  info(
+    "Set a mock for a sub-part of the path, which should not match require calls"
+  );
+  setMockedModule({ joinURI: () => "WRONG_PATH" }, "shared/path");
+
+  ok(
+    !getMockedModule(DEVTOOLS_MODULE_URI),
+    "Has no mock entry for the full URI"
+  );
+  const m2 = browserRequire(DEVTOOLS_MODULE_PATH);
+  is(
+    m2.joinURI("https://a", "b"),
+    "https://a/b",
+    "Original module is still required"
+  );
+
+  info(
+    "Set a mock for the complete path, which should now match require calls"
+  );
+  const mockedModule = {
+    joinURI: () => "MOCKED VALUE",
+  };
+  setMockedModule(mockedModule, DEVTOOLS_MODULE_PATH);
+  ok(
+    !!getMockedModule(DEVTOOLS_MODULE_URI),
+    "Has a mock entry for the full URI."
+  );
+
+  const m3 = browserRequire(DEVTOOLS_MODULE_PATH);
+  is(
+    m3.joinURI("https://a", "b"),
+    "MOCKED VALUE",
+    "The mocked module has been returned"
+  );
+
+  info(
+    "Check that the mocked methods can be updated after a destructuring import"
+  );
+  const { joinURI } = browserRequire(DEVTOOLS_MODULE_PATH);
+  mockedModule.joinURI = () => "UPDATED VALUE";
+  is(
+    joinURI("https://a", "b"),
+    "UPDATED VALUE",
+    "Mocked method was correctly updated"
+  );
+
+  removeMockedModule(DEVTOOLS_MODULE_PATH);
+  ok(
+    !getMockedModule(DEVTOOLS_MODULE_URI),
+    "Has no mock entry for the full URI"
+  );
+  const m4 = browserRequire(DEVTOOLS_MODULE_PATH);
+  is(
+    m4.joinURI("https://a", "b"),
+    "https://a/b",
+    "Original module can be required again"
+  );
+}
+
+function test() {
+  testWithChromeScheme();
+  testWithRegularDevtoolsModule();
+  delete window.getBrowserLoaderForWindow;
+  finish();
+}