Add base64 encoding for GCode prefix handling.

Implemented a `convertTobase64` function to encode strings to base64, ensuring they can be safely transmitted in JavaScript. Updated `EmscriptenCommunication::sendGCodePrefix` to use this new encoding method and modified relevant tests accordingly to check this functionality.

NP-327

include/utils/string.h

@@ -8,6 +8,9 @@
 #include <cstdio> // sprintf
 #include <ctype.h>
 #include <sstream> // ostringstream
+#include <boost/archive/iterators/base64_from_binary.hpp>
+#include <boost/archive/iterators/transform_width.hpp>
+#include <boost/archive/iterators/ostream_iterator.hpp>
 
 #include <spdlog/spdlog.h>
 
@@ -27,6 +30,31 @@ static inline int stringcasecompare(const char* a, const char* b)
     return *a - *b;
 }
 
+// Convert string to base64 string.
+// This function is useful to forward string through javascript even if they contain any special strings
+//
+[[maybe_unused]] static std::string convertTobase64(const std::string& input )
+{
+    using namespace boost::archive::iterators;
+    // prepare the stream to hold the encoded data
+    std::stringstream output;
+
+    // encode data
+    typedef base64_from_binary<transform_width<std::string::const_iterator, 6, 8>> base64_enc;
+    std::copy(base64_enc(input.begin()), base64_enc(input.end()),
+              ostream_iterator<char>(output));
+
+    // Retrieve the encoded string
+    std::string output_encoded = output.str();
+
+    // ensure padding if needed
+    size_t num = (3 - input.length() % 3) % 3;
+    for(size_t i = 0; i < num; i++)
+    {
+        output_encoded.push_back('=');
+    }
+    return output_encoded;
+}
 /*!
  * Efficient conversion of micron integer type to millimeter string.
  *

src/communication/EmscriptenCommunication.cpp

@@ -13,7 +13,7 @@
 #include <range/v3/algorithm/contains.hpp>
 #include <range/v3/iterator/operations.hpp>
 #include <spdlog/spdlog.h>
-
+#include "utils/string.h"
 #include "Application.h"
 #include "FffProcessor.h"
 #include "Slice.h"
@@ -41,7 +41,7 @@ EmscriptenCommunication::EmscriptenCommunication(const std::vector<std::string>&
 
 void EmscriptenCommunication::sendGCodePrefix(const std::string& prefix) const
 {
-    emscripten_run_script(fmt::format("globalThis[\"{}\"](\"{}\")", gcode_header_handler_, prefix).c_str());
+    emscripten_run_script(fmt::format("globalThis[\"{}\"](\"{}\")", gcode_prefix_handler_, convertTobase64(prefix)).c_str());
 }
 
 void EmscriptenCommunication::sendProgress(double progress) const

tests/arcus/ArcusCommunicationTest.cpp

@@ -14,6 +14,7 @@
 #include "geometry/Shape.h"
 #include "settings/types/LayerIndex.h"
 #include "utils/Coord_t.h"
+#include "utils/string.h"
 
 // NOLINTBEGIN(*-magic-numbers)
 namespace cura
@@ -123,15 +124,16 @@ TEST_F(ArcusCommunicationTest, HasSlice)
 
 TEST_F(ArcusCommunicationTest, SendGCodePrefix)
 {
-    const std::string& prefix = "bladibla";
+    const std::string prefix = ";bladiblhjvouyvu\n;iuboua";
+    const std::string& encoded_prefix = convertTobase64(prefix);
 
-    ac->sendGCodePrefix(prefix);
+    ac->sendGCodePrefix(encoded_prefix);
     ac->flushGCode();
     EXPECT_GT(socket->sent_messages.size(), 0);
     bool found_prefix = false;
     for (const auto& message : socket->sent_messages)
     {
-        if (message->DebugString().find(prefix) != std::string::npos)
+        if (message->DebugString().find(encoded_prefix) != std::string::npos)
         {
             found_prefix = true;
             break;