Allow disabling Blob Cxx module (#11979)

* Define FetchTest

* Implement fetch test

* Allow disabling Blob Cxx module

* Change files

* Format FetchTest.js

* yarn lint

change/react-native-windows-8d9e88e3-ce8b-46b7-a11e-af04d9f3d59d.json

@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "Allow disabling Blob Cxx module",
+  "packageName": "react-native-windows",
+  "email": "julio.rocha@microsoft.com",
+  "dependentChangeType": "patch"
+}

vnext/Desktop.IntegrationTests/RNTesterIntegrationTests.cpp

@@ -223,5 +223,12 @@ TEST_CLASS (RNTesterIntegrationTests) {
     Assert::AreEqual(TestStatus::Passed, result.Status, result.Message.c_str());
   }
 
+  BEGIN_TEST_METHOD_ATTRIBUTE(Fetch)
+  END_TEST_METHOD_ATTRIBUTE()
+  TEST_METHOD(Fetch) {
+    auto result = m_runner.RunTest("IntegrationTests/FetchTest", "FetchTest");
+    Assert::AreEqual(TestStatus::Passed, result.Status, result.Message.c_str());
+  }
+
 #pragma endregion Extended Tests
 };

vnext/Shared/OInstance.cpp

@@ -554,17 +554,20 @@ std::vector<std::unique_ptr<NativeModule>> InstanceImpl::GetDefaultNativeModules
       },
       nativeQueue));
 
-  modules.push_back(std::make_unique<CxxNativeModule>(
-      m_innerInstance,
-      Microsoft::React::GetBlobModuleName(),
-      [transitionalProps]() { return Microsoft::React::CreateBlobModule(transitionalProps); },
-      nativeQueue));
+  // Use in case the host app provides its a non-Blob-compatilbe HTTP module.
+  if (!Microsoft::React::GetRuntimeOptionBool("Blob.DisableModule")) {
+    modules.push_back(std::make_unique<CxxNativeModule>(
+        m_innerInstance,
+        Microsoft::React::GetBlobModuleName(),
+        [transitionalProps]() { return Microsoft::React::CreateBlobModule(transitionalProps); },
+        nativeQueue));
 
-  modules.push_back(std::make_unique<CxxNativeModule>(
-      m_innerInstance,
-      Microsoft::React::GetFileReaderModuleName(),
-      [transitionalProps]() { return Microsoft::React::CreateFileReaderModule(transitionalProps); },
-      nativeQueue));
+    modules.push_back(std::make_unique<CxxNativeModule>(
+        m_innerInstance,
+        Microsoft::React::GetFileReaderModuleName(),
+        [transitionalProps]() { return Microsoft::React::CreateFileReaderModule(transitionalProps); },
+        nativeQueue));
+  }
 
   modules.push_back(std::make_unique<CxxNativeModule>(
       m_innerInstance,

vnext/overrides.json

@@ -156,6 +156,10 @@
       "type": "platform",
       "file": "src/IntegrationTests/DummyTest.js"
     },
+    {
+      "type": "platform",
+      "file": "src/IntegrationTests/FetchTest.js"
+    },
     {
       "type": "platform",
       "file": "src/IntegrationTests/LoggingTest.js"

vnext/src/IntegrationTests/FetchTest.js

@@ -0,0 +1,53 @@
+/**
+ * Copyright (c) Microsoft Corporation.
+ * Licensed under the MIT License.
+ * @format
+ * @flow
+ */
+
+'use strict';
+
+const React = require('react');
+const ReactNative = require('react-native');
+
+const {AppRegistry, View} = ReactNative;
+
+const {TestModule} = ReactNative.NativeModules;
+
+const uri =
+  'https://raw.githubusercontent.com/microsoft/react-native-windows/main/.yarnrc.yml';
+const expectedContent = 'enableScripts: false';
+
+type State = {
+  uri: string,
+  expected: string,
+  content: string,
+};
+
+class FetchTest extends React.Component<{...}, State> {
+  state: State = {
+    uri: 'https://raw.githubusercontent.com/microsoft/react-native-windows/main/.yarnrc.yml',
+    expected: 'enableScripts: false',
+    content: '',
+  };
+
+  async componentDidMount() {
+    const response = await fetch(uri);
+    const text = await response.text();
+    this.setState({content: text});
+
+    if (this.state.content === expectedContent) {
+      TestModule.markTestPassed(true);
+    } else {
+      TestModule.markTestPassed(false);
+    }
+  }
+
+  render(): React.Node {
+    return <View />;
+  }
+}
+
+AppRegistry.registerComponent('FetchTest', () => FetchTest);
+
+module.exports = FetchTest;