fix(windows): unhandled exception thrown in std::_Xlen_string()

.github/workflows/build.yml

@@ -368,7 +368,7 @@ jobs:
     steps:
       - name: Set up MSBuild
         uses: microsoft/[email protected]
-      - name: Setup VSTest.console.exe
+      - name: Set up VSTest.console.exe
         uses: darenm/Setup-VSTest@v1
       - name: Set up Node.js
         uses: actions/setup-node@v1

example/windows/ReactTestAppTests/ManifestTests.cpp

@@ -8,6 +8,7 @@
 #include "pch.h"
 
 #include <CppUnitTest.h>
+#include <filesystem>
 #include <string>
 
 #include "Manifest.h"
@@ -17,6 +18,19 @@ using namespace Microsoft::VisualStudio::CppUnitTestFramework;
 using ReactTestApp::Component;
 using ReactTestApp::Manifest;
 
+std::string fixturePath(std::filesystem::path file)
+{
+    // Current working directory when running tests (with VSTest.Console.exe)
+    // changed between Visual Studio 16.8 and 16.9 and broke our pipelines. To
+    // prevent future build failures, we'll use the absolute path to this
+    // source file to build the path to the test fixtures.
+    //
+    // To ensure that `__FILE__` is a full path, we must also enable `/FC` in
+    // Properties > C/C++ > Advanced.
+    const auto p = std::filesystem::path(__FILE__).replace_filename("manifestTestFiles") / file;
+    return p.string();
+}
+
 // disable clang-format because it doesn't handle macros very well
 // clang-format off
 namespace ReactTestAppTests
@@ -26,7 +40,7 @@ namespace ReactTestAppTests
     public:
         TEST_METHOD(ParseManifestWithOneComponent)
         {
-            auto result = ReactTestApp::GetManifest("manifestTestFiles/simpleManifest.json");
+            auto result = ReactTestApp::GetManifest(fixturePath("simpleManifest.json"));
             if (!result.has_value()) {
                 Assert::Fail(L"Couldn't read manifest file");
             }
@@ -42,7 +56,7 @@ namespace ReactTestAppTests
 
         TEST_METHOD(ParseManifestWithMultipleComponents)
         {
-            auto result = ReactTestApp::GetManifest("manifestTestFiles/withMultipleComponents.json");
+            auto result = ReactTestApp::GetManifest(fixturePath("withMultipleComponents.json"));
             if (!result.has_value()) {
                 Assert::Fail(L"Couldn't read manifest file");
             }
@@ -67,7 +81,7 @@ namespace ReactTestAppTests
 
         TEST_METHOD(ParseManifestWithComplexInitialProperties)
         {
-            auto result = ReactTestApp::GetManifest("manifestTestFiles/withComplexInitialProperties.json");
+            auto result = ReactTestApp::GetManifest(fixturePath("withComplexInitialProperties.json"));
             if (!result.has_value()) {
                 Assert::Fail(L"Couldn't read manifest file");
             }

windows/ReactTestApp/Manifest.cpp

@@ -9,8 +9,7 @@
 
 #include "Manifest.h"
 
-#include <fstream>
-#include <iostream>
+#include <cstdio>
 
 #include <nlohmann/json.hpp>
 #include <winrt/Windows.Security.Cryptography.Core.h>
@@ -116,16 +115,18 @@ namespace ReactTestApp
 
     std::optional<std::pair<Manifest, std::string>> GetManifest(std::string const &filename)
     {
-        std::string json;
-        {
-            std::ifstream stream(filename);
+        std::FILE *stream = nullptr;
+        if (fopen_s(&stream, filename.c_str(), "rb") != 0) {
+            return std::nullopt;
+        }
 
-            stream.seekg(0, std::ios::end);
-            json.reserve(static_cast<size_t>(stream.tellg()));
+        std::string json;
+        std::fseek(stream, 0, SEEK_END);
+        json.resize(std::ftell(stream));
 
-            stream.seekg(0, std::ios::beg);
-            json.assign(std::istreambuf_iterator<char>(stream), {});
-        }
+        std::rewind(stream);
+        std::fread(json.data(), 1, json.size(), stream);
+        std::fclose(stream);
 
         auto j = nlohmann::json::parse(json, nullptr, false);
         if (j.is_discarded()) {