JSON-RPC test server (#2026)

* #include an absolute path didn't work - because paths were taken to always be relative.

* Use 'Process' to communicate with an command line tool.

* Remove slang-win-stream

* Tidy up windows ProcessUtil.

* First version of BufferedReadStream.

* Windows working IPC for steams.

* Test proxy count option.

* Split Process/ProcessUtil. Process is platform dependant. ProcessUtil are functions that are platform independent.

* First implementation of Unix Process interface.

* Unix process compiles on cygwin.

* Fix typo in unix process.

* Separate unix pipe stream error of invalid access, from pipe availability.

* Fix in standard line extraction.

* Make fd non blocking.

* Fix issues with Windows Process streams.

* Added UnixPipe.

* Some fixes around UnixPipeStream.

* Make a unix stream closed explicit.

* Hack to debug linux process/stream.

* Revert to old linux pipe handling.

* Pass executable path for unit tests.
Split out CommandLine into own source.

* Small improvements in process/command line.

* Check process behavior with crash.

* Make stderr and stdout unbuffered for crash testing.

* Only turn disable buffering in crash test.

* Disable crash test on CI.

* Fix crash on clang/linux.

* Enable crash test.
Remove _appendBuffer as can use StreamUtil functionality.

* Added inital processing for http headers.

* Small improvements to HttpHeader.

* First pass HTTPPacketConnection working on windows.

* Enable other Process communication tests.

* Update comments.

* WIP JSON RPC.

* Add terminate to Process.
Made JSONRPC a Util.

* Small tidy up around HTTPPacketConnection.

* Improve process termination options.

* WIP for test-server.

* Add diagnostics error handling to test-server.

* Improved JSON support.
Parsing/creating JSON-RPC messages.

* WIP JSONRPC parsing.

* First pass RttiInfo support.

* WIP converting between JSON/native types.

* Project files.

* Split out RttiUtil.
Made RttiInfo constuction thread safe.

* WIP RTTI<->JSON.

* Add diagnostics to JSON<->native conversions.

* Make RttiInfo for structs globals. Avoids problem around derived types (like pointers), being able to cause an abort.

* Add pointer support to RTTI.
Fixed some compilation issues on linux.

* Add fixed array support.

* Added Rtti unit test.

* Add rtti unit test.

* Split out quoted/unquoted key handling.
Fix bugs in JSON value/container.
Added JSON native test.

* Make default array allocator use malloc/free.
Remove the new[] handler (doesn't work on visuals studio).

* Fix for linux warning.

* Remove some test code.

* Fix issues on x86 win.

* Fix warning on aarch64.

* Fix some bugs in JSON parsing/handling.
Make Rtti work copy/dtor/ctor struct types.

* Testing JSON<->native with fixed array.
Make makeArrayView explicit if it's just a single value.
Added array type.

* Fix getting arrayView.

* Improve JSON diagnostic name.

* First pass refactor using Rtti for JSON RPC.

* First pass of test server using RTTI/JSON-RPC.

* Added JSONRPCConnection.

* Fix some naming issues.

* First pass of test-server working.

* Added unit test support for JSON-RPC test server.

* Fix compilation issues on linux around template handling.

* Typo fix.

* Fix a bug around SourceLoc lookup with JSONContainer.

* Set the console type to console for ISlangWriters.

* Small improvements to test-server.

* Small improvements in test-server.

* Small fix.

13 files changed, 727 insertions, 416 deletions

diff --git a/source/compiler-core/slang-json-diagnostic-defs.h b/source/compiler-core/slang-json-diagnostic-defs.h
index 4733a3291..576f14beb 100644
--- a/source/compiler-core/slang-json-diagnostic-defs.h
+++ b/source/compiler-core/slang-json-diagnostic-defs.h
@@ -42,4 +42,11 @@ DIAGNOSTIC(20011, Error, fieldNotDefinedOnType, "field '$0' not defined on type
 DIAGNOSTIC(20011, Error, fieldRequiredOnType, "field '$0' required on '$1'")
 DIAGNOSTIC(20012, Error, tooManyElementsForArray, "too many elements ($0) for array array. Max allowed is $1")
 
+//
+// 3xxxx JSON-RPC
+//
+
+DIAGNOSTIC(30000, Error, argsAreInvalid, "Args for '%0' are invalid")
+
+
 #undef DIAGNOSTIC
diff --git a/source/compiler-core/slang-json-native.h b/source/compiler-core/slang-json-native.h
index 66f20aafb..f9ec93119 100644
--- a/source/compiler-core/slang-json-native.h
+++ b/source/compiler-core/slang-json-native.h
@@ -12,6 +12,8 @@ namespace Slang {
 struct JSONToNativeConverter
 {
     SlangResult convert(const JSONValue& value, const RttiInfo* rttiInfo, void* out);
+    template <typename T>
+    SlangResult convert(const JSONValue& value, T* in) { return convert(value, GetRttiInfo<T>::get(), (void*)in); }
 
     JSONToNativeConverter(JSONContainer* container, DiagnosticSink* sink):
         m_container(container),
@@ -32,6 +34,9 @@ struct NativeToJSONConverter
 {
     SlangResult convert(const RttiInfo* rttiInfo, const void* in, JSONValue& out);
 
+    template <typename T>
+    SlangResult convert(T* in, JSONValue& out) { return convert(GetRttiInfo<T>::get(), (const void*)in, out); }
+
     NativeToJSONConverter(JSONContainer* container, DiagnosticSink* sink) :
         m_container(container),
         m_sink(sink)
diff --git a/source/compiler-core/slang-json-rpc-connection.cpp b/source/compiler-core/slang-json-rpc-connection.cpp
new file mode 100644
index 000000000..20283070b
--- /dev/null
+++ b/source/compiler-core/slang-json-rpc-connection.cpp
@@ -0,0 +1,286 @@
+// slang-json-rpc-connection.cpp
+#include "slang-json-rpc-connection.h"
+
+#include "../core/slang-string-util.h"
+#include "../core/slang-process-util.h"
+
+#include "slang-json-rpc.h"
+#include "slang-json-native.h"
+
+namespace Slang {
+
+SlangResult JSONRPCConnection::init(HTTPPacketConnection* connection, Process* process)
+{
+    m_connection = connection;
+    m_process = process;
+
+    m_sourceManager.initialize(nullptr, nullptr);
+    m_diagnosticSink.init(&m_sourceManager, &JSONLexer::calcLexemeLocation);
+    m_container.setSourceManager(&m_sourceManager);
+
+    return SLANG_OK;
+}
+
+SlangResult JSONRPCConnection::initWithStdStreams(Process* process)
+{
+    RefPtr<Stream> stdinStream, stdoutStream;
+
+    Process::getStdStream(Process::StreamType::StdIn, stdinStream);
+    Process::getStdStream(Process::StreamType::StdOut, stdoutStream);
+
+    RefPtr<BufferedReadStream> readStream(new BufferedReadStream(stdinStream));
+
+    RefPtr<HTTPPacketConnection> connection = new HTTPPacketConnection(readStream, stdoutStream);
+    return init(connection, process);
+}
+
+void JSONRPCConnection::clearBuffers()
+{
+    m_sourceManager.reset();
+    m_diagnosticSink.reset();
+    m_container.reset();
+    m_jsonRoot.reset();
+}
+
+bool JSONRPCConnection::isActive()
+{
+    return m_connection->isActive() && (m_process == nullptr || !m_process->isTerminated());
+}
+
+JSONValue JSONRPCConnection::getMessageId()
+{
+    SLANG_ASSERT(hasMessage());
+    return JSONRPCUtil::getId(&m_container, m_jsonRoot);
+}
+
+void JSONRPCConnection::disconnect()
+{
+    if (m_process)
+    {
+        if (!m_process->isTerminated())
+        {
+            if (m_connection)
+            {
+                // Send. If succeeded, wait 
+                if (SLANG_SUCCEEDED(sendCall(UnownedStringSlice::fromLiteral("quit"))))
+                {
+                    // Wait for termination
+                    m_process->waitForTermination(m_terminationTimeOutInMs);
+                }
+            }
+
+            if (!m_process->isTerminated())
+            {
+                // Okay, just try terminating
+                m_process->waitForTermination(m_terminationTimeOutInMs);
+            }
+
+            // Okay just kill it then
+            if (!m_process->isTerminated())
+            {
+                m_process->kill(-1);
+            }
+        }
+        m_process.setNull();
+    }
+
+    m_connection.setNull();
+}
+
+SlangResult JSONRPCConnection::sendRPC(const RttiInfo* rttiInfo, const void* data)
+{
+    // Convert to JSON
+    NativeToJSONConverter converter(&m_container, &m_diagnosticSink);
+    JSONValue value;
+
+    SLANG_RETURN_ON_FAIL(converter.convert(rttiInfo, data, value));
+
+    // Convert to text
+    JSONWriter writer(JSONWriter::IndentationStyle::Allman);
+
+    m_container.traverseRecursively(value, &writer);
+    const StringBuilder& builder = writer.getBuilder();
+    return m_connection->write(builder.getBuffer(), builder.getLength());
+}
+
+SlangResult JSONRPCConnection::sendError(JSONRPC::ErrorCode code)
+{
+    return sendError(code, m_diagnosticSink.outputBuffer.getUnownedSlice());
+}
+
+SlangResult JSONRPCConnection::sendError(JSONRPC::ErrorCode errorCode, const UnownedStringSlice& msg)
+{
+    JSONRPCErrorResponse errorResponse;
+    errorResponse.error.code = Int(errorCode);
+    errorResponse.error.message = msg;
+
+    // TODO(JS):
+    // This is only appropriate if the sendError is for the current input message.
+    // We might want to add function that the client uses, which take the id as a parameter.
+
+    if (m_jsonRoot.isValid())
+    {
+        errorResponse.id = JSONRPCUtil::getId(&m_container, m_jsonRoot);
+    }
+    else
+    {
+        // If we don't have valid json, we set the id to be null per the spec
+        errorResponse.id = JSONValue::makeNull();
+    }
+
+    return sendRPC(&errorResponse);
+}
+
+SlangResult JSONRPCConnection::toNativeOrSendError(const JSONValue& value, const RttiInfo* info, void* dst)
+{
+    m_diagnosticSink.outputBuffer.Clear();
+    if (SLANG_FAILED(JSONRPCUtil::convertToNative(&m_container, value, &m_diagnosticSink, info, dst)))
+    {
+        return sendError(JSONRPC::ErrorCode::InvalidRequest);
+    }
+    return SLANG_OK;
+}
+
+SlangResult JSONRPCConnection::sendCall(const UnownedStringSlice& method, const JSONValue& id)
+{
+    JSONRPCCall call;
+    call.id = id;
+    call.method = method;
+
+    SLANG_RETURN_ON_FAIL(sendRPC(&call));
+    return SLANG_OK;
+}
+
+SlangResult JSONRPCConnection::sendResult(const RttiInfo* rttiInfo, const void* result, const JSONValue& id)
+{
+    JSONResultResponse response;
+    response.id = id;
+
+    NativeToJSONConverter converter(&m_container, &m_diagnosticSink);
+    SLANG_RETURN_ON_FAIL(converter.convert(rttiInfo, result, response.result));
+
+    // Send the RPC
+    SLANG_RETURN_ON_FAIL(sendRPC(&response));
+    return SLANG_OK;
+}
+
+SlangResult JSONRPCConnection::sendCall(const UnownedStringSlice& method, const RttiInfo* argsRttiInfo, const void* args, const JSONValue& id)
+{
+    JSONRPCCall call;
+    call.id = id;
+    call.method = method;
+
+    // Convert the args/params
+    NativeToJSONConverter converter(&m_container, &m_diagnosticSink);
+    SLANG_RETURN_ON_FAIL(converter.convert(argsRttiInfo, args, call.params));
+
+    // Send the RPC
+    SLANG_RETURN_ON_FAIL(sendRPC(&call));
+    return SLANG_OK;
+}
+
+SlangResult JSONRPCConnection::waitForResult(Int timeOutInMs)
+{
+    SLANG_RETURN_ON_FAIL(m_connection->waitForResult(timeOutInMs));
+    return tryReadMessage();
+}
+
+SlangResult JSONRPCConnection::tryReadMessage()
+{
+    m_jsonRoot.reset();
+
+    SLANG_RETURN_ON_FAIL(m_connection->update());
+    if (!m_connection->hasContent())
+    {
+        return SLANG_OK;
+    }
+
+    auto content = m_connection->getContent();
+    UnownedStringSlice slice((const char*)content.begin(), content.getCount());
+
+    clearBuffers();
+
+    {
+        const SlangResult res = JSONRPCUtil::parseJSON(slice, &m_container, &m_diagnosticSink, m_jsonRoot);
+
+        // Consume that content/packet
+        m_connection->consumeContent();
+        if (SLANG_FAILED(res))
+        {
+            return sendError(JSONRPC::ErrorCode::ParseError);
+        }
+    }
+
+    return SLANG_OK;
+}
+
+JSONRPCMessageType JSONRPCConnection::getMessageType()
+{
+    return JSONRPCUtil::getMessageType(&m_container, m_jsonRoot);
+}
+
+SlangResult JSONRPCConnection::getMessage(const RttiInfo* rttiInfo, void* out)
+{
+    if (!hasMessage())
+    {
+        return SLANG_FAIL;
+    }
+
+    m_diagnosticSink.outputBuffer.Clear();
+    JSONToNativeConverter converter(&m_container, &m_diagnosticSink);
+
+    // Get the RPC response
+    JSONResultResponse resultResponse;
+    SLANG_RETURN_ON_FAIL(converter.convert(m_jsonRoot, &resultResponse));
+
+    // Convert the result in the response
+    SLANG_RETURN_ON_FAIL(converter.convert(resultResponse.result, rttiInfo, out));
+    return SLANG_OK;
+}
+
+SlangResult JSONRPCConnection::getMessageOrSendError(const RttiInfo* rttiInfo, void* out)
+{
+    if (!hasMessage())
+    {
+        return SLANG_FAIL;
+    }
+
+    const auto res = getMessage(rttiInfo, out);
+    if (SLANG_FAILED(res))
+    {
+        return sendError(JSONRPC::ErrorCode::ParseError);
+    }
+    return res;
+}
+
+SlangResult JSONRPCConnection::getRPC(const RttiInfo* rttiInfo, void* out)
+{
+    if (!hasMessage())
+    {
+        return SLANG_FAIL;
+    }
+
+    m_diagnosticSink.outputBuffer.Clear();
+    JSONToNativeConverter converter(&m_container, &m_diagnosticSink);
+
+    // Convert the result in the response
+    SLANG_RETURN_ON_FAIL(converter.convert(m_jsonRoot, rttiInfo, out));
+    return SLANG_OK;
+}
+
+SlangResult JSONRPCConnection::getRPCOrSendError(const RttiInfo* rttiInfo, void* out)
+{
+    if (!hasMessage())
+    {
+        return SLANG_FAIL;
+    }
+
+    const auto res = getRPC(rttiInfo, out);
+    if (SLANG_FAILED(res))
+    {
+        return sendError(JSONRPC::ErrorCode::ParseError);
+    }
+    return res;
+}
+
+} // namespcae Slang
diff --git a/source/compiler-core/slang-json-rpc-connection.h b/source/compiler-core/slang-json-rpc-connection.h
new file mode 100644
index 000000000..730635493
--- /dev/null
+++ b/source/compiler-core/slang-json-rpc-connection.h
@@ -0,0 +1,161 @@
+#ifndef SLANG_COMPILER_CORE_JSON_RPC_CONNECTION_H
+#define SLANG_COMPILER_CORE_JSON_RPC_CONNECTION_H
+
+#include "../../source/core/slang-http.h"
+#include "../../source/core/slang-process.h"
+
+#include "slang-diagnostic-sink.h"
+#include "slang-source-loc.h"
+#include "slang-json-value.h"
+#include "slang-json-rpc.h"
+
+#include "slang-json-diagnostics.h"
+
+#include "slang-test-server-protocol.h"
+
+namespace Slang {
+
+/* TODO(JS):
+
+It's not really clear here, how to handle id handling. If a server can receive multiple messages, and then later send responses we need
+a way to queue up ids. This is complicated by JSONValue is only valid whilst the backing JSONContainer holds it.
+
+We probably want to create some kind of Variant that can hold all of these values that can hold state independently.
+*/
+class JSONRPCConnection : public RefObject
+{
+public:
+
+        /// An init function must be called before use
+        /// If a process is implementing the server it should be passed in if the process needs to shut down if the connection does
+    SlangResult init(HTTPPacketConnection* connection, Process* process = nullptr);
+
+        /// Initialize using stdin/out streams for input/output. 
+    SlangResult initWithStdStreams(Process* process = nullptr);
+
+        /// Disconnect. May block while server shuts down
+    void disconnect();
+
+        /// Convert value to dst. Will write response on fails
+    SlangResult toNativeOrSendError(const JSONValue& value, const RttiInfo* info, void* dst);
+    template <typename T>
+    SlangResult toNativeOrSendError(const JSONValue& value, T* data) { return toNativeOrSendError(value, GetRttiInfo<T>::get(), data); }
+
+    template <typename T>
+    SlangResult toValidNativeOrSendError(const JSONValue& value, T* data);
+
+        /// Send a RPC response (ie should only be one of the JSONRPC classes)
+    SlangResult sendRPC(const RttiInfo* info, const void* data);
+    template <typename T>
+    SlangResult sendRPC(const T* data) { return sendRPC(GetRttiInfo<T>::get(), (const void*)data);  }
+
+        /// Send an error
+    SlangResult sendError(JSONRPC::ErrorCode code);
+    SlangResult sendError(JSONRPC::ErrorCode errorCode, const UnownedStringSlice& msg);
+
+        /// Send a call
+        /// If no id is needed, id can just be invalid 
+    SlangResult sendCall(const UnownedStringSlice& method, const RttiInfo* argsRttiInfo, const void* args, const JSONValue& id = JSONValue());
+    template <typename T>
+    SlangResult sendCall(const UnownedStringSlice& method, const T* args, const JSONValue& id = JSONValue()) { return sendCall(method, GetRttiInfo<T>::get(), (const void*)args, id); }
+        ///
+    SlangResult sendCall(const UnownedStringSlice& method, const JSONValue& id = JSONValue());
+
+    template <typename T>
+    SlangResult sendResult(const T* result, const JSONValue& id = JSONValue()) { return sendResult(GetRttiInfo<T>::get(), (const void*)result, id); }
+    SlangResult sendResult(const RttiInfo* rttiInfo, const void* result, const JSONValue& id = JSONValue());
+
+        /// Try to read a message. Will return if message is not available.
+    SlangResult tryReadMessage();
+
+        /// Will block for message/result up to time
+    SlangResult waitForResult(Int timeOutInMs = -1);
+
+        /// If we have an JSON-RPC message m_jsonRoot the root.
+    bool hasMessage() const { return m_jsonRoot.isValid(); }
+
+        /// If there is a message returns kind of JSON RPC message
+    JSONRPCMessageType getMessageType();
+
+        /// Get JSON-RPC message (ie one of JSONRPC classes)
+    template <typename T>
+    SlangResult getRPC(T* out) { return getRPC(GetRttiInfo<T>::get(), (void*)out); }
+    SlangResult getRPC(const RttiInfo* rttiInfo, void* out);
+
+        /// Get JSON-RPC message (ie one of JSONRPC prefixed classes)
+        /// If there is a message and there is a failure, will send an error response
+    template <typename T>
+    SlangResult getRPCOrSendError(T* out) { return getRPCOrSendError(GetRttiInfo<T>::get(), (void*)out); }
+    SlangResult getRPCOrSendError(const RttiInfo* rttiInfo, void* out);
+
+    /// Get message (has to be part of JSONRPCResultResponse)
+    template <typename T>
+    SlangResult getMessage(T* out) { return getMessage(GetRttiInfo<T>::get(), (void*)out); }
+    SlangResult getMessage(const RttiInfo* rttiInfo, void* out);
+
+    /// If there is a message and there is a failure, will send an error response
+    template <typename T>
+    SlangResult getMessageOrSendError(T* out) { return getMessageOrSendError(GetRttiInfo<T>::get(), (void*)out); }
+    SlangResult getMessageOrSendError(const RttiInfo* rttiInfo, void* out);
+
+        /// Clears all the internal buffers (for JSON/Source/etc).
+        /// Happens automatically on tryReadMessage/readMessage
+    void clearBuffers();
+
+        /// True if this connection is active
+    bool isActive();
+
+        /// Get the id of the current message
+    JSONValue getMessageId();
+
+        /// Get the diagnostic sink. Can queue up errors before sending an error
+    DiagnosticSink* getSink() { return &m_diagnosticSink;  }
+
+        /// Dtor
+    ~JSONRPCConnection() { disconnect(); }
+
+        /// Ctor
+    JSONRPCConnection():m_container(nullptr) {}
+
+protected:
+    RefPtr<Slang::Process> m_process;                       ///< Backing process (optional)
+    RefPtr<Slang::HTTPPacketConnection> m_connection;
+
+    DiagnosticSink m_diagnosticSink;
+
+    SourceManager m_sourceManager;
+    JSONContainer m_container;
+
+    JSONValue m_jsonRoot;
+
+        /// Default timeout is 10 seconds
+    Int m_timeOutInMs = 10 * 1000;
+        /// Termination timeout
+    Int m_terminationTimeOutInMs = 1 * 1000;
+};
+
+// ---------------------------------------------------------------------------
+template <typename T>
+SlangResult JSONRPCConnection::toValidNativeOrSendError(const JSONValue& value, T* data)
+{
+    const RttiInfo* rttiInfo = GetRttiInfo<T>::get();
+
+    SLANG_RETURN_ON_FAIL(toNativeOrSendError(value, rttiInfo, (void*)data));
+    if (!data->isValid())
+    {
+        // If it has a name add validation info
+        if (rttiInfo->isNamed())
+        {
+            const NamedRttiInfo* namedRttiInfo = static_cast<const NamedRttiInfo*>(rttiInfo);
+            m_diagnosticSink.diagnose(SourceLoc(), JSONDiagnostics::argsAreInvalid, namedRttiInfo->m_name);
+        }
+
+        return sendError(JSONRPC::ErrorCode::InvalidRequest);
+    }
+    return SLANG_OK;
+}
+
+} // namespace Slang
+
+#endif // SLANG_COMPILER_CORE_JSON_RPC_CONNECTION_H
+
diff --git a/source/compiler-core/slang-json-rpc.cpp b/source/compiler-core/slang-json-rpc.cpp
index 1ca55e9eb..660bbd4b7 100644
--- a/source/compiler-core/slang-json-rpc.cpp
+++ b/source/compiler-core/slang-json-rpc.cpp
@@ -2,23 +2,20 @@
 
 #include "../../slang-com-helper.h"
 
+#include "slang-json-native.h"
+
 namespace Slang {
 
 // https://www.jsonrpc.org/specification
 
-//    m_sourceManager.initialize(nullptr, nullptr);
-//    m_diagnosticSink.init(&m_sourceManager, &JSONLexer::calcLexemeLocation);
 
-static const auto g_jsonRpc = UnownedStringSlice::fromLiteral("jsonrpc");
-static const auto g_jsonRpcVersion = UnownedStringSlice::fromLiteral("2.0");
-static const auto g_method = UnownedStringSlice::fromLiteral("method");
-static const auto g_id = UnownedStringSlice::fromLiteral("id");
-static const auto g_params = UnownedStringSlice::fromLiteral("params");
-static const auto g_code = UnownedStringSlice::fromLiteral("code");
-static const auto g_error = UnownedStringSlice::fromLiteral("error");
-static const auto g_message = UnownedStringSlice::fromLiteral("message");
+/* static */ const UnownedStringSlice JSONRPC::jsonRpc = UnownedStringSlice::fromLiteral("jsonrpc");
+/* static */const UnownedStringSlice JSONRPC::jsonRpcVersion = UnownedStringSlice::fromLiteral("2.0");
+/* static */const UnownedStringSlice JSONRPC::id = UnownedStringSlice::fromLiteral("id");
+
 static const auto g_result = UnownedStringSlice::fromLiteral("result");
-static const auto g_data = UnownedStringSlice::fromLiteral("data");
+static const auto g_error = UnownedStringSlice::fromLiteral("error");
+static const auto g_method = UnownedStringSlice::fromLiteral("method");
 
 // Add the fields.
 // TODO(JS): This is a little verbose, and could be improved on with something like
@@ -39,9 +36,10 @@ static const StructRttiInfo _makeJSONRPCErrorResponseRtti()
     JSONRPCErrorResponse obj;
     StructRttiBuilder builder(&obj, "JSONRPCErrorResponse", nullptr);
 
+    builder.addField("jsonrpc", &obj.jsonrpc);
     builder.addField("error", &obj.error);
     builder.addField("data", &obj.data, StructRttiInfo::Flag::Optional);
-    builder.addField("id", &obj.id, combine(StructRttiInfo::Flag::Optional, RttiDefaultValue::MinusOne));
+    builder.addField("id", &obj.id, StructRttiInfo::Flag::Optional);
 
     return builder.make();
 }
@@ -52,9 +50,10 @@ static const StructRttiInfo _makeJSONRPCCallResponseRtti()
     JSONRPCCall obj;
     StructRttiBuilder builder(&obj, "JSONRPCCall", nullptr);
 
+    builder.addField("jsonrpc", &obj.jsonrpc);
     builder.addField("method", &obj.method);
     builder.addField("params", &obj.params, StructRttiInfo::Flag::Optional);
-    builder.addField("id", &obj.id, combine(StructRttiInfo::Flag::Optional, RttiDefaultValue::MinusOne));
+    builder.addField("id", &obj.id, StructRttiInfo::Flag::Optional);
 
     return builder.make();
 }
@@ -65,350 +64,44 @@ static const StructRttiInfo _makeJSONResultResponseResponseRtti()
     JSONResultResponse obj;
     StructRttiBuilder builder(&obj, "JSONResultResponse", nullptr);
 
+    builder.addField("jsonrpc", &obj.jsonrpc);
     builder.addField("result", &obj.result);
-    builder.addField("id", &obj.id, combine(StructRttiInfo::Flag::Optional, RttiDefaultValue::MinusOne));
+    builder.addField("id", &obj.id, StructRttiInfo::Flag::Optional);
 
     return builder.make();
 }
 /* static */const StructRttiInfo JSONResultResponse::g_rttiInfo = _makeJSONResultResponseResponseRtti();
 
-
-/* static */JSONValue JSONRPCUtil::createCall(JSONContainer* container, const UnownedStringSlice& method, JSONValue params, Int id)
-{
-    const Index maxPairs = 4;
-    JSONKeyValue pairs[maxPairs];
-
-    Index i = 0;
-
-    // Version number is a string
-    pairs[i++] = JSONKeyValue::make(container->getKey(g_jsonRpc), container->createString(g_jsonRpcVersion));
-    pairs[i++] = JSONKeyValue::make(container->getKey(g_method), container->createString(method));
-    pairs[i++] = JSONKeyValue::make(container->getKey(g_params), params);
-
-    if (id >= 0)
-    {
-        pairs[i++] = JSONKeyValue::make(container->getKey(g_id), JSONValue::makeInt(id));
-    }
-
-    return container->createObject(pairs, i);
-}
-
-/* static */JSONValue JSONRPCUtil::createCall(JSONContainer* container, const UnownedStringSlice& method, Int id)
-{
-    const Index maxPairs = 3;
-    JSONKeyValue pairs[maxPairs];
-    Index i = 0;
-    // Version number is a string
-    pairs[i++] = JSONKeyValue::make(container->getKey(g_jsonRpc), container->createString(g_jsonRpcVersion));
-    pairs[i++] = JSONKeyValue::make(container->getKey(g_method), container->createString(method));
-
-    if (id >= 0)
-    {
-        pairs[i++] = JSONKeyValue::make(container->getKey(g_id), JSONValue::makeInt(id));
-    }
-
-    return container->createObject(pairs, i);
-}
-
-/* static */JSONValue JSONRPCUtil::createErrorResponse(JSONContainer* container, Index code, const UnownedStringSlice& message, const JSONValue& data, Int id)
-{
-    // Set up the error value
-    JSONValue errorValue;
-    {
-        const Index maxPairs = 2;
-        JSONKeyValue pairs[maxPairs];
-        Index i = 0;
-
-        if (code != 0)
-        {
-            pairs[i++] = JSONKeyValue::make(container->getKey(g_code), JSONValue::makeInt(code));
-        }
-        if (message.getLength() > 0)
-        {
-            pairs[i++] = JSONKeyValue::make(container->getKey(g_message), container->createString(message));
-        }
-        errorValue = container->createObject(pairs, i);
-    }
-
-    const Index maxPairs = 4;
-    JSONKeyValue pairs[maxPairs];
-    Index i = 0;
-
-    pairs[i++] = JSONKeyValue::make(container->getKey(g_jsonRpc), container->createString(g_jsonRpcVersion));
-    pairs[i++] = JSONKeyValue::make(container->getKey(g_error), errorValue);
-
-    if (data.isValid())
-    {
-        pairs[i++] = JSONKeyValue::make(container->getKey(g_data), data);
-    }
-
-    if (id >= 0)
-    {
-        pairs[i++] = JSONKeyValue::make(container->getKey(g_id), JSONValue::makeInt(id));
-    }
-
-    return container->createObject(pairs, i);
-}
-
-
-/* static */JSONValue JSONRPCUtil::createErrorResponse(JSONContainer* container, ErrorCode code, const UnownedStringSlice& message, const JSONValue& data, Int id)
-{
-    return createErrorResponse(container, Index(code), message, data, id);
-}
-
-/* static */JSONValue JSONRPCUtil::createResultResponse(JSONContainer* container, const JSONValue& resultValue, Int id)
+/* static */JSONRPCMessageType JSONRPCUtil::getMessageType(JSONContainer* container, const JSONValue& value)
 {
-    const Index maxPairs = 3;
-    JSONKeyValue pairs[maxPairs];
-    Index i = 0;
-
-    pairs[i++] = JSONKeyValue::make(container->getKey(g_jsonRpc), container->createString(g_jsonRpcVersion));
-    pairs[i++] = JSONKeyValue::make(container->getKey(g_result), resultValue);
-
-    if (id >= 0)
-    {
-        pairs[i++] = JSONKeyValue::make(container->getKey(g_id), JSONValue::makeInt(id));
-    }
-
-    return container->createObject(pairs, i);
-}
-
-/* static */ JSONRPCUtil::ResponseType JSONRPCUtil::getResponseType(JSONContainer* container, const JSONValue& response)
-{
-    if (response.getKind() == JSONValue::Kind::Object)
+    if (value.getKind() == JSONValue::Kind::Object)
     {
         const JSONKey resultKey = container->findKey(g_result);
         const JSONKey errorKey = container->findKey(g_error);
+        const JSONKey methodKey = container->findKey(g_method);
 
-        auto pairs = container->getObject(response);
+        auto pairs = container->getObject(value);
 
         for (const auto& pair : pairs)
         {
             if (pair.key == resultKey)
             {
-                return ResponseType::Result;
+                return JSONRPCMessageType::Result;
             }
             else if (pair.key == errorKey)
             {
-                return ResponseType::Error;
-            }
-        }
-    }
-
-    return ResponseType::Error;
-}
-
-static SlangResult _parseError(JSONContainer* container, const JSONValue& error, JSONRPCUtil::ErrorResponse& out)
-{
-    if (error.getKind() != JSONValue::Kind::Object)
-    {
-        return SLANG_FAIL;
-    }
-    const auto pairs = container->getObject(error);
-
-    const JSONKey messageKey = container->findKey(g_message);
-    const JSONKey codeKey = container->findKey(g_code);
-    const JSONKey dataKey = container->findKey(g_data);
-
-    Int fieldBits = 0;
-
-    for (auto const& pair : pairs)
-    {
-        if (pair.key == messageKey)
-        {
-            if (pair.value.getKind() != JSONValue::Kind::String)
-            {
-                return SLANG_FAIL;
-            }
-            out.message = container->getString(pair.value);
-            fieldBits |= 0x1;
-        }
-        else if (pair.key == codeKey)
-        {
-            if (pair.value.getKind() != JSONValue::Kind::Integer)
-            {
-                return SLANG_FAIL;
-            }
-            out.code = Index(pair.value.asInteger());
-            fieldBits |= 0x2;
-        }
-        else if (pair.key == dataKey)
-        {
-            out.data = pair.value;
-            fieldBits |= 0x4;
-        }
-        else
-        {
-            return SLANG_FAIL;
-        }
-    }
-
-    // Check all required fields are set
-    return (fieldBits & 0x3) == 0x3 ? SLANG_OK : SLANG_FAIL;
-}
-
-/* static */SlangResult JSONRPCUtil::parseError(JSONContainer* container, const JSONValue& response, ErrorResponse& out)
-{
-    if (response.getKind() != JSONValue::Kind::Object)
-    {
-        return SLANG_FAIL;
-    }
-
-    const auto pairs = container->getObject(response);
-
-    const JSONKey jsonRpcKey = container->findKey(g_jsonRpc);
-    const JSONKey errorKey = container->findKey(g_error);
-    const JSONKey idKey = container->findKey(g_id);
-
-    Int fieldBits = 0;
-
-    for (auto const& pair : pairs)
-    {
-        if (pair.key == jsonRpcKey)
-        {
-            if (!container->areEqual(pair.value, g_jsonRpcVersion))
-            {
-                return SLANG_FAIL;
-            }
-            fieldBits |= 0x1;
-        }
-        else if (pair.key == errorKey)
-        {
-            // We need to decode the error 
-            SLANG_RETURN_ON_FAIL(_parseError(container, pair.value, out));
-            fieldBits |= 0x2;
-        }
-        else if (pair.key == idKey)
-        {
-            if (pair.value.getKind() != JSONValue::Kind::Integer)
-            {
-                return SLANG_FAIL;
-            }
-            out.id = Int(pair.value.asInteger());
-            fieldBits |= 0x4;
-        }
-        else
-        {
-            // Unknown key
-            return SLANG_FAIL;
-        }
-    }
-
-    // Check all the required bits are set
-    return ((fieldBits & 0x3) == 0x3) ? SLANG_OK : SLANG_FAIL;
-}
-
-/* static */SlangResult JSONRPCUtil::parseResult(JSONContainer* container, const JSONValue& response, ResultResponse& out)
-{
-    if (response.getKind() != JSONValue::Kind::Object)
-    {
-        return SLANG_FAIL;
-    }
-
-    const auto pairs = container->getObject(response);
-
-    const JSONKey jsonRpcKey = container->findKey(g_jsonRpc);
-    const JSONKey resultKey = container->findKey(g_result);
-    const JSONKey idKey = container->findKey(g_id);
-
-    Int fieldBits = 0;
-
-    for (auto const& pair : pairs)
-    {
-        if (pair.key == jsonRpcKey)
-        {
-            if (!container->areEqual(pair.value, g_jsonRpcVersion))
-            {
-                return SLANG_FAIL;
-            }
-            fieldBits |= 0x1;
-        }
-        else if (pair.key == resultKey)
-        {
-            out.result = pair.value;
-            fieldBits |= 0x2;
-        }
-        else if (pair.key == idKey)
-        {
-            if (pair.value.getKind() != JSONValue::Kind::Integer)
-            {
-                return SLANG_FAIL;
-            }
-            out.id = Int(pair.value.asInteger());
-            fieldBits |= 0x4;
-        }
-        else
-        {
-            // Unknown key
-            return SLANG_FAIL;
-        }
-    }
-
-    // Check all the required bits are set
-    return ((fieldBits & 0x3) == 0x3) ? SLANG_OK : SLANG_FAIL;
-}
-
-/* static */SlangResult JSONRPCUtil::parseCall(JSONContainer* container, const JSONValue& value, Call& out)
-{
-    if (value.getKind() != JSONValue::Kind::Object)
-    {
-        return SLANG_FAIL;
-    }
-
-    const auto pairs = container->getObject(value);
-
-    const JSONKey jsonRpcKey = container->findKey(g_jsonRpc);
-    const JSONKey methodKey = container->findKey(g_method);
-    const JSONKey paramsKey = container->findKey(g_params);
-    const JSONKey idKey = container->findKey(g_id);
-
-    Int fieldBits = 0;
-
-    for (auto const& pair : pairs)
-    {
-        if (pair.key == jsonRpcKey)
-        {
-            if (!container->areEqual(pair.value, g_jsonRpcVersion))
-            {
-                return SLANG_FAIL;
+                return JSONRPCMessageType::Error;
             }
-            fieldBits |= 0x1;
-        }
-        else if (pair.key == methodKey)
-        {
-            if (pair.value.getKind() != JSONValue::Kind::String)
-            {
-                return SLANG_FAIL;
-            }
-            out.method = container->getString(pair.value);
-            fieldBits |= 0x2;
-        }
-        else if (pair.key == idKey)
-        {
-            if (pair.value.getKind() != JSONValue::Kind::Integer)
+            else if (pair.key == methodKey)
             {
-                return SLANG_FAIL;
+                return JSONRPCMessageType::Call;
             }
-            out.id = Int(pair.value.asInteger());
-            fieldBits |= 0x4;
-        }
-        else if (pair.key == paramsKey)
-        {
-            out.params = pair.value;
-            fieldBits |= 0x8;
-        }
-        else
-        {
-            // Unknown key
-            return SLANG_FAIL;
         }
     }
 
-    // Check all the required bits are set
-    return ((fieldBits & 0x3) == 0x3) ? SLANG_OK : SLANG_FAIL;
+    return JSONRPCMessageType::Invalid;
 }
 
-
 /* static */SlangResult JSONRPCUtil::parseJSON(const UnownedStringSlice& slice, JSONContainer* container, DiagnosticSink* sink, JSONValue& outValue)
 {
     SourceManager* sourceManager = sink->getSourceManager();
@@ -430,21 +123,50 @@ static SlangResult _parseError(JSONContainer* container, const JSONValue& error,
     return SLANG_OK;
 }
 
-SlangResult JSONRPCUtil::parseJSONAndConsume(HTTPPacketConnection* connection, JSONContainer* container, DiagnosticSink* sink, JSONValue& outValue)
+/* static */SlangResult JSONRPCUtil::convertToNative(JSONContainer* container, const JSONValue& value, DiagnosticSink* sink, const RttiInfo* rttiInfo, void* out)
 {
-    if (!connection->hasContent())
-    {
-        return SLANG_FAIL;
-    }
+    JSONToNativeConverter converter(container, sink);
+    SLANG_RETURN_ON_FAIL(converter.convert(value, rttiInfo, out));
+    return SLANG_OK;
+}
 
-    auto content = connection->getContent();
+/* static */SlangResult JSONRPCUtil::convertToJSON(const RttiInfo* rttiInfo, const void* in, DiagnosticSink* sink, StringBuilder& out)
+{
+    SourceManager* sourceManager = sink->getSourceManager();
+    JSONContainer container(sourceManager);
 
-    UnownedStringSlice text((const char*)content.begin(), content.getCount());
-    SlangResult res = parseJSON(text, container, sink, outValue);
+    NativeToJSONConverter converter(&container, sink);
 
-    // Consume the content
-    connection->consumeContent();
-    return res;
+    JSONValue value;
+    SLANG_RETURN_ON_FAIL(converter.convert(rttiInfo, in, value));
+
+    // Convert into a string
+    JSONWriter writer(JSONWriter::IndentationStyle::Allman);
+    container.traverseRecursively(value, &writer);
+
+    out = writer.getBuilder();
+    return SLANG_OK;
 }
 
+/* static */JSONValue JSONRPCUtil::getId(JSONContainer* container, const JSONValue& root)
+{
+    if (root.getKind() == JSONValue::Kind::Object)
+    {
+        const JSONKey key = container->findKey(JSONRPC::id);
+
+        if (key != JSONKey(0))
+        {
+            auto obj = container->getObject(root);
+            Index index = obj.findFirstIndex([key](const JSONKeyValue& pair) -> bool { return pair.key == key; });
+
+            if (index >= 0)
+            {
+                return obj[index].value;
+            }
+        }
+    }
+    return JSONValue();
+}
+
+
 } // namespace Slang
diff --git a/source/compiler-core/slang-json-rpc.h b/source/compiler-core/slang-json-rpc.h
index e85664ceb..f32513b02 100644
--- a/source/compiler-core/slang-json-rpc.h
+++ b/source/compiler-core/slang-json-rpc.h
@@ -12,115 +12,124 @@
 
 namespace Slang {
 
+/// Struct to hold values associated with JSON-RPC
+struct JSONRPC
+{
+    enum class ErrorCode
+    {
+        ParseError = -32700,        ///< Invalid JSON was received by the server.
+        InvalidRequest = -32600,    ///< The JSON sent is not a valid Request object.
+        MethodNotFound = -32601,    ///< The method does not exist / is not available.
+        InvalidParams = -32602,     ///< Invalid method parameter(s).
+        InternalError = -32603, 	///< Internal JSON - RPC error.
+
+        ServerImplStart = -32000,   ///< Server implementation defined error range
+        ServerImplEnd = -32099,
+    };
+
+    static bool isIdOk(const JSONValue& value)
+    {
+        auto kind = value.getKind();
+        switch (kind)
+        {
+            case JSONValue::Kind::Integer:
+            case JSONValue::Kind::Invalid:
+            case JSONValue::Kind::String:
+            {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    static const UnownedStringSlice jsonRpc;
+    static const UnownedStringSlice jsonRpcVersion;
+    static const UnownedStringSlice id;
+};
+
 struct JSONRPCErrorResponse
 {
     struct Error
     {
-        Index code = 0;                     ///< Value from ErrorCode
-        UnownedStringSlice message;         ///< Error message
+        bool isValid() const { return code != 0; }
 
+        Int code = 0;                     ///< Value from ErrorCode
+        UnownedStringSlice message;         ///< Error message
+    
         static const StructRttiInfo g_rttiInfo;
     };
 
+    bool isValid() const { return jsonrpc == JSONRPC::jsonRpcVersion && error.isValid() && JSONRPC::isIdOk(id);  }
+
+    UnownedStringSlice jsonrpc = JSONRPC::jsonRpcVersion;
     Error error;
-    JSONValue data;                 
-    Int id = -1;                        ///< Id of initiating method or -1 if not set
+    JSONValue data;                      ///< Optional data describing the errro
+    JSONValue id;                        ///< Id associated with this request
 
     static const StructRttiInfo g_rttiInfo;
 };
 
 struct JSONRPCCall
 {
+    bool isValid() const { return method.getLength() > 0 && jsonrpc == JSONRPC::jsonRpcVersion && JSONRPC::isIdOk(id);  }
+
+    UnownedStringSlice jsonrpc = JSONRPC::jsonRpcVersion;
     UnownedStringSlice method;          ///< The name of the method
     JSONValue params;                   ///< Can be invalid/array/object
-    Int id = -1;                        ///< Id associated with this request, or -1 if not set
+    JSONValue id;                       ///< Id associated with this request
 
     static const StructRttiInfo g_rttiInfo;
 };
 
 struct JSONResultResponse
 {
-    JSONValue result;                   ///< The result value
-    Int id = -1;                        ///< Id of initiating method or -1 if not set
+    bool isValid() const { return jsonrpc == JSONRPC::jsonRpcVersion && JSONRPC::isIdOk(id); }
+
+    UnownedStringSlice jsonrpc = JSONRPC::jsonRpcVersion;
+    JSONValue result;                           ///< The result value
+    JSONValue id;                               ///< Id associated with this request 
 
     static const StructRttiInfo g_rttiInfo;
 };
 
+enum class JSONRPCMessageType
+{
+    Invalid,
+    Result,
+    Call,
+    Error,
+    CountOf,
+};
+
 /// Send and receive messages as JSON
-///
-/// Strictly speaking should support ids, as strings or ids. Currently just supports with integer ids.
-/// One way of dealing with this would be to just use JSONValue for ids, would allow invalid/string/integer and
-/// a mechanism to compare/display etc.
 class JSONRPCUtil
 {
 public:
 
-    enum class ErrorCode
-    {
-        ParseError = -32700,        ///< Invalid JSON was received by the server.
-        InvalidRequest = -32600,    ///< The JSON sent is not a valid Request object.
-        MethodNotFound = -32601,    ///< The method does not exist / is not available.
-        InvalidParams = -32602,     ///< Invalid method parameter(s).
-        InternalError = -32603, 	///< Internal JSON - RPC error.
-
-        ServerImplStart = -32000,   ///< Server implementation defined error range
-        ServerImplEnd = -32099,
-    };
-
-    enum class ResponseType
-    {
-        Invalid,
-        Error,
-        Result
-    };
-
-    struct ErrorResponse
-    {
-        Index code = 0;                     ///< Value from ErrorCode
-        UnownedStringSlice message;         ///< Error message
-        JSONValue data;
-        Int id = -1;                        ///< Id of initiating method or -1 if not set
-    };
-
-    struct ResultResponse
-    {
-        JSONValue result;                   ///< The result value
-        Int id = -1;                        ///< Id of initiating method or -1 if not set
-    };
-
-    struct Call
-    {
-        UnownedStringSlice method;          ///< The name of the method
-        JSONValue params;                   ///< Can be invalid/array/object
-        Int id = -1;                        ///< Id associated with this request, or -1 if not set
-    };
-
-        /// Parameters can be either named or via index.
-    static JSONValue createCall(JSONContainer* container, const UnownedStringSlice& method, JSONValue params, Int id = -1);
-        /// Parameters can be either named or via index.
-    static JSONValue createCall(JSONContainer* container, const UnownedStringSlice& method, Int id = -1);
-
-        /// Create an error response
-        /// Code should typically be something in the ErrorCode range
-    static JSONValue createErrorResponse(JSONContainer* container, Index code, const UnownedStringSlice& message, const JSONValue& data = JSONValue(), Int id = -1);
-    static JSONValue createErrorResponse(JSONContainer* container, ErrorCode code, const UnownedStringSlice& message, const JSONValue& data = JSONValue(), Int id = -1);
-        /// Create a result response
-    static JSONValue createResultResponse(JSONContainer* container, const JSONValue& resultValue, Int id = -1);
-
         /// Determine the response type
-    static ResponseType getResponseType(JSONContainer* container, const JSONValue& response);
+    static JSONRPCMessageType getMessageType(JSONContainer* container, const JSONValue& value);
 
-    static SlangResult parseError(JSONContainer* container, const JSONValue& response, ErrorResponse& out);
+        /// Parse slice into JSONContainer. outValue is the root of the hierarchy.
+        /// NOTE! Uses and *assumes* there is a source manager on the sink. outValue is likely only usable whilst the sourceManger is in scope
+        /// The sourceLoc can only be interpretted with the sourceLoc anyway
+    static SlangResult parseJSON(const UnownedStringSlice& slice, JSONContainer* container, DiagnosticSink* sink, JSONValue& outValue);
 
-    static SlangResult parseResult(JSONContainer* container, const JSONValue& response, ResultResponse& out);
+        /// Convert value into out
+    static SlangResult convertToNative(JSONContainer* container, const JSONValue& value, DiagnosticSink* sink, const RttiInfo* rttiInfo, void* out);
+    template <typename T>
+    static SlangResult convertToNative(JSONContainer* container, const JSONValue& value, DiagnosticSink* sink, T& out) { return convertToNative(container, value, sink, GetRttiInfo<T>::get(), (void*)&out); }
 
-    static SlangResult parseCall(JSONContainer* container, const JSONValue& value, Call& out);
+        /// Convert to JSON
+    static SlangResult convertToJSON(const RttiInfo* rttiInfo, const void* in, DiagnosticSink* sink, StringBuilder& out);
 
-        /// Parse slice into JSONContainer. outValue is the root of the hierarchy.
-    static SlangResult parseJSON(const UnownedStringSlice& slice, JSONContainer* container, DiagnosticSink* sink, JSONValue& outValue);
+    template <typename T>
+    static SlangResult convertToJSON(const T* in, DiagnosticSink* sink, StringBuilder& out)
+    {
+        return convertToJSON(GetRttiInfo<T>::get(), (const void*)in, sink, out);
+    }
 
-        /// Parse content from stream, and consume the packet
-    static SlangResult parseJSONAndConsume(HTTPPacketConnection* connection, JSONContainer* container, DiagnosticSink* sink, JSONValue& outValue);
+        /// Get an id directly from root (assumed id: is in root object definition).
+    static JSONValue getId(JSONContainer* container, const JSONValue& root);
 };
 
 } // namespace Slang
diff --git a/source/compiler-core/slang-json-value.cpp b/source/compiler-core/slang-json-value.cpp
index 4fad3764f..216512407 100644
--- a/source/compiler-core/slang-json-value.cpp
+++ b/source/compiler-core/slang-json-value.cpp
@@ -164,6 +164,8 @@ void JSONContainer::reset()
     m_objectValues.clear();
 
     _addRange(Range::Type::None, 0, 0);
+
+    m_currentView = nullptr;
 }
 
 /* static */bool JSONContainer::areKeysUnique(const JSONKeyValue* keyValues, Index keyValueCount)
diff --git a/source/compiler-core/slang-json-value.h b/source/compiler-core/slang-json-value.h
index 119479285..b94283d81 100644
--- a/source/compiler-core/slang-json-value.h
+++ b/source/compiler-core/slang-json-value.h
@@ -100,7 +100,7 @@ struct JSONValue
         /// Given a type return the associated kind
     static Kind getKindForType(Type type) { return g_typeToKind[Index(type)]; }
 
-    Type type;                  ///< The type of value
+    Type type = Type::Invalid;  ///< The type of value
     SourceLoc loc;              ///< The (optional) location in source of this value.
 
     union 
@@ -112,6 +112,7 @@ struct JSONValue
         JSONKey stringKey;          ///< The pool key if it's a string
     };
 
+
     static const Kind g_typeToKind[Index(Type::CountOf)];
 
     static const OtherRttiInfo g_rttiInfo;
diff --git a/source/compiler-core/slang-test-server-protocol.cpp b/source/compiler-core/slang-test-server-protocol.cpp
new file mode 100644
index 000000000..2a3bb3a3b
--- /dev/null
+++ b/source/compiler-core/slang-test-server-protocol.cpp
@@ -0,0 +1,43 @@
+#include "slang-test-server-protocol.h"
+
+namespace TestServerProtocol {
+
+static const StructRttiInfo _makeExecuteUnitTestArgsRtti()
+{
+    ExecuteUnitTestArgs obj;
+    StructRttiBuilder builder(&obj, "TestServerProtocol::ExecuteUnitTestArgs", nullptr);
+
+    builder.addField("moduleName", &obj.moduleName);
+    builder.addField("testName", &obj.testName);
+    builder.addField("enabledApis", &obj.enabledApis);
+    return builder.make();
+}
+/* static */const UnownedStringSlice ExecuteUnitTestArgs::g_methodName = UnownedStringSlice::fromLiteral("unitTest");
+/* static */const StructRttiInfo ExecuteUnitTestArgs::g_rttiInfo = _makeExecuteUnitTestArgsRtti();
+
+static const StructRttiInfo _makeExecuteToolTestArgsRtti()
+{
+    ExecuteToolTestArgs obj;
+    StructRttiBuilder builder(&obj, "TestServerProtocol::ExecuteToolTestArgs", nullptr);
+    builder.addField("toolName", &obj.toolName);
+    builder.addField("args", &obj.args);
+    return builder.make();
+}
+/* static */const StructRttiInfo ExecuteToolTestArgs::g_rttiInfo = _makeExecuteToolTestArgsRtti();
+/* static */const UnownedStringSlice ExecuteToolTestArgs::g_methodName = UnownedStringSlice::fromLiteral("tool");
+
+static const StructRttiInfo _makeExecutionResultRtti()
+{
+    ExecutionResult obj;
+    StructRttiBuilder builder(&obj, "TestServerProtocol::ExecutionResult", nullptr);
+    builder.addField("stdOut", &obj.stdOut);
+    builder.addField("stdError", &obj.stdError);
+    builder.addField("result", &obj.result);
+    builder.addField("returnCode", &obj.returnCode);
+    return builder.make();
+}
+/* static */const StructRttiInfo ExecutionResult::g_rttiInfo = _makeExecutionResultRtti();
+
+/* static */const UnownedStringSlice QuitArgs::g_methodName = UnownedStringSlice::fromLiteral("quit");
+
+} // namespace TestServerProtocol
diff --git a/source/compiler-core/slang-test-server-protocol.h b/source/compiler-core/slang-test-server-protocol.h
new file mode 100644
index 000000000..8b61c4b39
--- /dev/null
+++ b/source/compiler-core/slang-test-server-protocol.h
@@ -0,0 +1,51 @@
+#ifndef SLANG_COMPILER_CORE_TEST_PROTOCOL_H
+#define SLANG_COMPILER_CORE_TEST_PROTOCOL_H
+
+#include "../../slang.h"
+#include "../../slang-com-helper.h"
+#include "../../slang-com-ptr.h"
+
+#include "../core/slang-rtti-info.h"
+#include "slang-json-value.h"
+
+namespace TestServerProtocol {
+
+using namespace Slang;
+
+struct ExecuteUnitTestArgs
+{
+    String moduleName;
+    String testName;
+    uint32_t enabledApis;
+
+    static const UnownedStringSlice g_methodName;
+    static const StructRttiInfo g_rttiInfo;
+};
+
+struct ExecuteToolTestArgs
+{
+    String toolName;                ///< The name of the tool (will be a shared library typically - like render-test). Doesn't need -tool suffix.
+    List<String> args;                          ///< Arguments passed to the tool during exectution
+
+    static const UnownedStringSlice g_methodName;
+    static const StructRttiInfo g_rttiInfo;
+};
+
+struct QuitArgs
+{
+    static const UnownedStringSlice g_methodName;
+};
+
+struct ExecutionResult
+{
+    String stdOut;
+    String stdError;
+    int32_t result = SLANG_OK;
+    int32_t returnCode = 0;                         ///< As returned if invoked as command line
+
+    static const StructRttiInfo g_rttiInfo;
+};
+
+} // namespace Slang
+
+#endif // SLANG_COMPILER_CORE_TEST_PROTOCOL_H
diff --git a/source/core/slang-http.cpp b/source/core/slang-http.cpp
index 43be26c1c..6a4bb4f92 100644
--- a/source/core/slang-http.cpp
+++ b/source/core/slang-http.cpp
@@ -287,8 +287,19 @@ SlangResult HTTPPacketConnection::update()
     return m_readResult;
 }
 
-SlangResult HTTPPacketConnection::waitForResult()
+SlangResult HTTPPacketConnection::waitForResult(Int timeOutInMs)
 {
+    m_readResult = SLANG_OK;
+
+    int64_t startTick = 0;
+    int64_t timeOutInTicks = -1;
+
+    if (timeOutInMs >= 0)
+    {
+        timeOutInTicks = timeOutInMs * (Process::getClockFrequency() / 1000);
+        startTick = Process::getClockTick();
+    }
+
     while (m_readState == ReadState::Header ||
         m_readState == ReadState::Content)
     {
@@ -296,6 +307,17 @@ SlangResult HTTPPacketConnection::waitForResult()
 
         SLANG_RETURN_ON_FAIL(update());
 
+        if (m_readState == ReadState::Done)
+        {
+            break;
+        }
+
+        // We timed out
+        if (timeOutInTicks >= 0 && int64_t(Process::getClockTick()) - startTick >= timeOutInTicks)
+        {
+            break;
+        }
+
         if (prevCount == m_readStream->getCount())
         {
             // Yield if it appears nothing was read.
diff --git a/source/core/slang-http.h b/source/core/slang-http.h
index a298e9e27..784357273 100644
--- a/source/core/slang-http.h
+++ b/source/core/slang-http.h
@@ -123,8 +123,9 @@ public:
         /// Write. Will potentially block if write stream is blocking.
     SlangResult write(const void* content, size_t sizeInBytes);
 
-        /// Blocks until some result - a packet, closure, or some kind of error
-    SlangResult waitForResult();
+        /// Blocks until some result - a packet, closure, or some kind of error or timeout.
+        /// TimeOut of -1 means no timeout.
+    SlangResult waitForResult(Int timeOutInMs = -1);
         /// Consume the content - so can read next content
     void consumeContent();
 
diff --git a/source/core/slang-writer.h b/source/core/slang-writer.h
index 380823b39..7c768a22f 100644
--- a/source/core/slang-writer.h
+++ b/source/core/slang-writer.h
@@ -148,6 +148,7 @@ public:
         Parent(flags),
         m_builder(builder)
     {}
+    ~StringWriter() {}
 
 protected:
     StringBuilder* m_builder;