Create tests that roundtrip output through a conpty to a Terminal (#4213

)

## Summary of the Pull Request

This PR adds two tests:
* First, I started by writing a test where I could write output to the console  host and inspect what output came out of conpty. This is the `ConptyOutputTests` in the host unit tests.
* Then I got crazy and thought _"what if I could take that output and dump it straight into the `Terminal`"_? Hence, the `ConptyRoundtripTests` were born, into the TerminalCore unit tests.

## References

Done in pursuit of #4200, but I felt this warranted it's own atomic PR

## PR Checklist
* [x] Doesn't close anything on it's own.
* [x] I work here
* [x] you better believe this adds tests
* [n/a] Requires documentation to be updated

## Detailed Description of the Pull Request / Additional comments

From the comment in `ConptyRoundtripTests`:
> This test class creates an in-proc conpty host as well as a Terminal, to
> validate that strings written to the conpty create the same resopnse on the
> terminal end. Tests can be written that validate both the contents of the
> host buffer as well as the terminal buffer. Everytime that
> `renderer.PaintFrame()` is called, the tests will validate the expected
> output, and then flush the output of the VtEngine straight to th

Also, some other bits had to be updated:
* The renderer needed to be able to survive without a thread, so I hadded a simple check that it actually had a thread before calling `pThread->NotifyPaint`
* Bits in `CommonState` used `NTSTATUS_FROM_HRESULT` which did _not_ work outside the host project. Since the `NTSTATUS` didn't seem that important, I replaced that with a `HRESULT`
* `CommonState` likes to initialize the console to some _weird_ defaults. I added an optional param to let us just use the defaults.

src/cascadia/TerminalCore/Terminal.hpp

@@ -28,6 +28,11 @@ namespace Microsoft::Terminal::Core
     class Terminal;
 }
 
+// fwdecl unittest classes
+#ifdef UNIT_TESTING
+class ConptyRoundtripTests;
+#endif
+
 class Microsoft::Terminal::Core::Terminal final :
     public Microsoft::Terminal::Core::ITerminalApi,
     public Microsoft::Terminal::Core::ITerminalInput,
@@ -245,4 +250,8 @@ class Microsoft::Terminal::Core::Terminal final :
     SMALL_RECT _GetSelectionRow(const SHORT row, const COORD higherCoord, const COORD lowerCoord) const;
     void _ExpandSelectionRow(SMALL_RECT& selectionRow) const;
 #pragma endregion
+
+#ifdef UNIT_TESTING
+    friend class ::ConptyRoundtripTests;
+#endif
 };

src/cascadia/UnitTests_TerminalCore/ConptyRoundtripTests.cpp

@@ -0,0 +1,366 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+//
+// This test class creates an in-proc conpty host as well as a Terminal, to
+// validate that strings written to the conpty create the same resopnse on the
+// terminal end. Tests can be written that validate both the contents of the
+// host buffer as well as the terminal buffer. Everytime that
+// `renderer.PaintFrame()` is called, the tests will validate the expected
+// output, and then flush the output of the VtEngine straight to the Terminal.
+
+#include "precomp.h"
+#include <wextestclass.h>
+#include "../../inc/consoletaeftemplates.hpp"
+#include "../../types/inc/Viewport.hpp"
+#include "../../types/inc/convert.hpp"
+
+#include "../renderer/inc/DummyRenderTarget.hpp"
+#include "../../renderer/base/Renderer.hpp"
+#include "../../renderer/vt/Xterm256Engine.hpp"
+#include "../../renderer/vt/XtermEngine.hpp"
+#include "../../renderer/vt/WinTelnetEngine.hpp"
+
+class InputBuffer; // This for some reason needs to be fwd-decl'd
+#include "../host/inputBuffer.hpp"
+#include "../host/readDataCooked.hpp"
+#include "test/CommonState.hpp"
+
+#include "../cascadia/TerminalCore/Terminal.hpp"
+
+using namespace WEX::Common;
+using namespace WEX::Logging;
+using namespace WEX::TestExecution;
+using namespace Microsoft::Console::Types;
+using namespace Microsoft::Console::Interactivity;
+using namespace Microsoft::Console::VirtualTerminal;
+
+using namespace Microsoft::Console;
+using namespace Microsoft::Console::Render;
+using namespace Microsoft::Console::Types;
+
+using namespace Microsoft::Terminal::Core;
+
+class ConptyRoundtripTests
+{
+    TEST_CLASS(ConptyRoundtripTests);
+
+    TEST_CLASS_SETUP(ClassSetup)
+    {
+        m_state = std::make_unique<CommonState>();
+
+        m_state->InitEvents();
+        m_state->PrepareGlobalFont();
+        m_state->PrepareGlobalScreenBuffer();
+        m_state->PrepareGlobalInputBuffer();
+
+        return true;
+    }
+
+    TEST_CLASS_CLEANUP(ClassCleanup)
+    {
+        m_state->CleanupGlobalScreenBuffer();
+        m_state->CleanupGlobalFont();
+        m_state->CleanupGlobalInputBuffer();
+
+        m_state.release();
+
+        return true;
+    }
+
+    TEST_METHOD_SETUP(MethodSetup)
+    {
+        // STEP 1: Set up the Terminal
+        term = std::make_unique<Terminal>();
+        term->Create({ CommonState::s_csBufferWidth, CommonState::s_csBufferHeight }, 0, emptyRT);
+
+        // STEP 2: Set up the Conpty
+
+        // Set up some sane defaults
+        auto& g = ServiceLocator::LocateGlobals();
+        auto& gci = g.getConsoleInformation();
+        gci.SetDefaultForegroundColor(INVALID_COLOR);
+        gci.SetDefaultBackgroundColor(INVALID_COLOR);
+        gci.SetFillAttribute(0x07); // DARK_WHITE on DARK_BLACK
+
+        m_state->PrepareNewTextBufferInfo(true);
+        auto& currentBuffer = gci.GetActiveOutputBuffer();
+        // Make sure a test hasn't left us in the alt buffer on accident
+        VERIFY_IS_FALSE(currentBuffer._IsAltBuffer());
+        VERIFY_SUCCEEDED(currentBuffer.SetViewportOrigin(true, { 0, 0 }, true));
+        VERIFY_ARE_EQUAL(COORD({ 0, 0 }), currentBuffer.GetTextBuffer().GetCursor().GetPosition());
+
+        g.pRender = new Renderer(&gci.renderData, nullptr, 0, nullptr);
+
+        // Set up an xterm-256 renderer for conpty
+        wil::unique_hfile hFile = wil::unique_hfile(INVALID_HANDLE_VALUE);
+        Viewport initialViewport = currentBuffer.GetViewport();
+
+        _pVtRenderEngine = std::make_unique<Xterm256Engine>(std::move(hFile),
+                                                            gci,
+                                                            initialViewport,
+                                                            gci.GetColorTable(),
+                                                            static_cast<WORD>(gci.GetColorTableSize()));
+        auto pfn = std::bind(&ConptyRoundtripTests::_writeCallback, this, std::placeholders::_1, std::placeholders::_2);
+        _pVtRenderEngine->SetTestCallback(pfn);
+
+        g.pRender->AddRenderEngine(_pVtRenderEngine.get());
+        gci.GetActiveOutputBuffer().SetTerminalConnection(_pVtRenderEngine.get());
+
+        expectedOutput.clear();
+
+        return true;
+    }
+
+    TEST_METHOD_CLEANUP(MethodCleanup)
+    {
+        m_state->CleanupNewTextBufferInfo();
+
+        auto& g = ServiceLocator::LocateGlobals();
+        delete g.pRender;
+
+        VERIFY_ARE_EQUAL(0u, expectedOutput.size(), L"Tests should drain all the output they push into the expected output buffer.");
+
+        term = nullptr;
+
+        return true;
+    }
+
+    TEST_METHOD(ConptyOutputTestCanary);
+    TEST_METHOD(SimpleWriteOutputTest);
+    TEST_METHOD(WriteTwoLinesUsesNewline);
+    TEST_METHOD(WriteAFewSimpleLines);
+
+private:
+    bool _writeCallback(const char* const pch, size_t const cch);
+    void _flushFirstFrame();
+    std::deque<std::string> expectedOutput;
+    std::unique_ptr<Microsoft::Console::Render::VtEngine> _pVtRenderEngine;
+    std::unique_ptr<CommonState> m_state;
+
+    DummyRenderTarget emptyRT;
+    std::unique_ptr<Terminal> term;
+};
+
+bool ConptyRoundtripTests::_writeCallback(const char* const pch, size_t const cch)
+{
+    std::string actualString = std::string(pch, cch);
+    VERIFY_IS_GREATER_THAN(expectedOutput.size(),
+                           static_cast<size_t>(0),
+                           NoThrowString().Format(L"writing=\"%hs\", expecting %u strings", actualString.c_str(), expectedOutput.size()));
+
+    std::string first = expectedOutput.front();
+    expectedOutput.pop_front();
+
+    Log::Comment(NoThrowString().Format(L"Expected =\t\"%hs\"", first.c_str()));
+    Log::Comment(NoThrowString().Format(L"Actual =\t\"%hs\"", actualString.c_str()));
+
+    VERIFY_ARE_EQUAL(first.length(), cch);
+    VERIFY_ARE_EQUAL(first, actualString);
+
+    // Write the string back to our Terminal
+    const auto converted = ConvertToW(CP_UTF8, actualString);
+    term->Write(converted);
+
+    return true;
+}
+
+void ConptyRoundtripTests::_flushFirstFrame()
+{
+    auto& g = ServiceLocator::LocateGlobals();
+    auto& renderer = *g.pRender;
+
+    expectedOutput.push_back("\x1b[2J");
+    expectedOutput.push_back("\x1b[m");
+    expectedOutput.push_back("\x1b[H"); // Go Home
+    expectedOutput.push_back("\x1b[?25h");
+
+    VERIFY_SUCCEEDED(renderer.PaintFrame());
+}
+
+// Function Description:
+// - Helper function to validate that a number of characters in a row are all
+//   the same. Validates that the next end-start characters are all equal to the
+//   provided string. Will move the provided iterator as it validates. The
+//   caller should ensure that `iter` starts where they would like to validate.
+// Arguments:
+// - expectedChar: The character (or characters) we're expecting
+// - iter: a iterator pointing to the cell we'd like to start validating at.
+// - start: the first index in the range we'd like to validate
+// - end: the last index in the range we'd like to validate
+// Return Value:
+// - <none>
+void _verifySpanOfText(const wchar_t* const expectedChar,
+                       TextBufferCellIterator& iter,
+                       const int start,
+                       const int end)
+{
+    for (int x = start; x < end; x++)
+    {
+        SetVerifyOutput settings(VerifyOutputSettings::LogOnlyFailures);
+        if (iter->Chars() != expectedChar)
+        {
+            Log::Comment(NoThrowString().Format(L"character [%d] was mismatched", x));
+        }
+        VERIFY_ARE_EQUAL(expectedChar, (iter++)->Chars());
+    }
+    Log::Comment(NoThrowString().Format(
+        L"Successfully validated %d characters were '%s'", end - start, expectedChar));
+}
+
+// Function Description:
+// - Helper function to validate that the next characters pointed to by `iter`
+//   are the provided string. Will increment iter as it walks the provided
+//   string of characters. It will leave `iter` on the first character after the
+//   expectedString.
+// Arguments:
+// - expectedString: The characters we're expecting
+// - iter: a iterator pointing to the cell we'd like to start validating at.
+// Return Value:
+// - <none>
+void _verifyExpectedString(std::wstring_view expectedString,
+                           TextBufferCellIterator& iter)
+{
+    for (const auto wch : expectedString)
+    {
+        wchar_t buffer[]{ wch, L'\0' };
+        std::wstring_view view{ buffer, 1 };
+        VERIFY_IS_TRUE(iter, L"Ensure iterator is still valid");
+        VERIFY_ARE_EQUAL(view, (iter++)->Chars(), NoThrowString().Format(L"%s", view.data()));
+    }
+}
+
+// Function Description:
+// - Helper function to validate that the next characters in the buffer at the
+//   given location are the provided string. Will return an iterator on the
+//   first character after the expectedString.
+// Arguments:
+// - tb: the buffer who's content we should check
+// - expectedString: The characters we're expecting
+// - pos: the starting position in the buffer to check the contents of
+// Return Value:
+// - an iterator on the first character after the expectedString.
+TextBufferCellIterator _verifyExpectedString(const TextBuffer& tb,
+                                             std::wstring_view expectedString,
+                                             const COORD pos)
+{
+    auto iter = tb.GetCellDataAt(pos);
+    _verifyExpectedString(expectedString, iter);
+    return iter;
+}
+
+void ConptyRoundtripTests::ConptyOutputTestCanary()
+{
+    Log::Comment(NoThrowString().Format(
+        L"This is a simple test to make sure that everything is working as expected."));
+    VERIFY_IS_NOT_NULL(_pVtRenderEngine.get());
+
+    _flushFirstFrame();
+}
+
+void ConptyRoundtripTests::SimpleWriteOutputTest()
+{
+    Log::Comment(NoThrowString().Format(
+        L"Write some simple output, and make sure it gets rendered largely "
+        L"unmodified to the terminal"));
+    VERIFY_IS_NOT_NULL(_pVtRenderEngine.get());
+
+    auto& g = ServiceLocator::LocateGlobals();
+    auto& renderer = *g.pRender;
+    auto& gci = g.getConsoleInformation();
+    auto& si = gci.GetActiveOutputBuffer();
+    auto& hostSm = si.GetStateMachine();
+    auto& termTb = *term->_buffer;
+
+    _flushFirstFrame();
+
+    expectedOutput.push_back("Hello World");
+    hostSm.ProcessString(L"Hello World");
+
+    VERIFY_SUCCEEDED(renderer.PaintFrame());
+
+    _verifyExpectedString(termTb, L"Hello World ", { 0, 0 });
+}
+
+void ConptyRoundtripTests::WriteTwoLinesUsesNewline()
+{
+    Log::Comment(NoThrowString().Format(
+        L"Write two lines of output. We should use \r\n to move the cursor"));
+    VERIFY_IS_NOT_NULL(_pVtRenderEngine.get());
+
+    auto& g = ServiceLocator::LocateGlobals();
+    auto& renderer = *g.pRender;
+    auto& gci = g.getConsoleInformation();
+    auto& si = gci.GetActiveOutputBuffer();
+    auto& hostSm = si.GetStateMachine();
+    auto& hostTb = si.GetTextBuffer();
+    auto& termTb = *term->_buffer;
+
+    _flushFirstFrame();
+
+    hostSm.ProcessString(L"AAA");
+    hostSm.ProcessString(L"\x1b[2;1H");
+    hostSm.ProcessString(L"BBB");
+
+    auto verifyData = [](TextBuffer& tb) {
+        _verifyExpectedString(tb, L"AAA", { 0, 0 });
+        _verifyExpectedString(tb, L"BBB", { 0, 1 });
+    };
+
+    verifyData(hostTb);
+
+    expectedOutput.push_back("AAA");
+    expectedOutput.push_back("\r\n");
+    expectedOutput.push_back("BBB");
+
+    VERIFY_SUCCEEDED(renderer.PaintFrame());
+
+    verifyData(termTb);
+}
+
+void ConptyRoundtripTests::WriteAFewSimpleLines()
+{
+    Log::Comment(NoThrowString().Format(
+        L"Write more lines of outout. We should use \r\n to move the cursor"));
+    VERIFY_IS_NOT_NULL(_pVtRenderEngine.get());
+
+    auto& g = ServiceLocator::LocateGlobals();
+    auto& renderer = *g.pRender;
+    auto& gci = g.getConsoleInformation();
+    auto& si = gci.GetActiveOutputBuffer();
+    auto& hostSm = si.GetStateMachine();
+    auto& hostTb = si.GetTextBuffer();
+    auto& termTb = *term->_buffer;
+
+    _flushFirstFrame();
+
+    hostSm.ProcessString(L"AAA\n");
+    hostSm.ProcessString(L"BBB\n");
+    hostSm.ProcessString(L"\n");
+    hostSm.ProcessString(L"CCC");
+    auto verifyData = [](TextBuffer& tb) {
+        _verifyExpectedString(tb, L"AAA", { 0, 0 });
+        _verifyExpectedString(tb, L"BBB", { 0, 1 });
+        _verifyExpectedString(tb, L"   ", { 0, 2 });
+        _verifyExpectedString(tb, L"CCC", { 0, 3 });
+    };
+
+    verifyData(hostTb);
+
+    expectedOutput.push_back("AAA");
+    expectedOutput.push_back("\r\n");
+    expectedOutput.push_back("BBB");
+    expectedOutput.push_back("\r\n");
+    // Here, we're going to emit 3 spaces. The region that got invalidated was a
+    // rectangle from 0,0 to 3,3, so the vt renderer will try to render the
+    // region in between BBB and CCC as well, because it got included in the
+    // rectangle Or() operation.
+    // This behavior should not be seen as binding - if a future optimization
+    // breaks this test, it wouldn't be the worst.
+    expectedOutput.push_back("   ");
+    expectedOutput.push_back("\r\n");
+    expectedOutput.push_back("CCC");
+
+    VERIFY_SUCCEEDED(renderer.PaintFrame());
+
+    verifyData(termTb);
+}