5 files changed, 100 insertions, 0 deletions
diff --git a/src/corelib/doc/snippets/code/src_corelib_text_qbytearray.cpp b/src/corelib/doc/snippets/code/src_corelib_text_qbytearray.cpp
index 8a9cb7c841..2a780f1c49 100644
--- a/src/corelib/doc/snippets/code/src_corelib_text_qbytearray.cpp
+++ b/src/corelib/doc/snippets/code/src_corelib_text_qbytearray.cpp
@@ -461,4 +461,15 @@ QByteArray ba = QByteArrayLiteral("byte array contents");
 QByteArray encoded("Qt%20is%20great%33");
 QByteArray decoded = encoded.percentDecoded(); // Set to "Qt is great!"
 //! [54]
+
+//! [55]
+emscripten::val uint8array = emscripten::val::global("g_uint8array");
+QByteArray byteArray = QByteArray::fromUint8Array(uint8array);
+//! [55]
+
+//! [56]
+QByteArray byteArray = "test";
+emscripten::val uint8array = QByteArray::toUint8Array(byteArray);
+//! [56]
+
 }
diff --git a/src/corelib/platform/wasm/qstdweb.cpp b/src/corelib/platform/wasm/qstdweb.cpp
index 363a21ee8d..69ed8fe34f 100644
--- a/src/corelib/platform/wasm/qstdweb.cpp
+++ b/src/corelib/platform/wasm/qstdweb.cpp
@@ -573,6 +573,18 @@ void Uint8Array::copyTo(char *destination) const
     Uint8Array(destination, length()).set(*this);
 }
 
+// Copies the Uint8Array content to a destination QByteArray
+QByteArray Uint8Array::copyToQByteArray() const
+{
+    if (length() > std::numeric_limits<qsizetype>::max())
+        return QByteArray();
+
+    QByteArray destinationArray;
+    destinationArray.resize(length());
+    copyTo(destinationArray.data());
+    return destinationArray;
+}
+
 // Copies the Uint8Array content to a destination on the heap
 void Uint8Array::copy(char *destination, const Uint8Array &source)
 {
@@ -587,6 +599,12 @@ Uint8Array Uint8Array::copyFrom(const char *buffer, uint32_t size)
     return contentCopy;
 }
 
+// Copies content from a QByteArray to a new Uint8Array object
+Uint8Array Uint8Array::copyFrom(const QByteArray &buffer)
+{
+    return copyFrom(buffer.constData(), buffer.size());
+}
+
 emscripten::val Uint8Array::val()
 {
     return m_uint8Array;
diff --git a/src/corelib/platform/wasm/qstdweb_p.h b/src/corelib/platform/wasm/qstdweb_p.h
index badca5d402..b3fc8a95f7 100644
--- a/src/corelib/platform/wasm/qstdweb_p.h
+++ b/src/corelib/platform/wasm/qstdweb_p.h
@@ -128,8 +128,11 @@ namespace qstdweb {
         void set(const Uint8Array &source);
 
         void copyTo(char *destination) const;
+        QByteArray copyToQByteArray() const;
+
         static void copy(char *destination, const Uint8Array &source);
         static Uint8Array copyFrom(const char *buffer, uint32_t size);
+        static Uint8Array copyFrom(const QByteArray &buffer);
         emscripten::val val();
 
     private:
diff --git a/src/corelib/text/qbytearray.cpp b/src/corelib/text/qbytearray.cpp
index ec17c0e15a..9eabf22600 100644
--- a/src/corelib/text/qbytearray.cpp
+++ b/src/corelib/text/qbytearray.cpp
@@ -18,6 +18,9 @@
 #include "qstringconverter_p.h"
 #include <qdatastream.h>
 #include <qmath.h>
+#if defined(Q_OS_WASM)
+#include "private/qstdweb_p.h"
+#endif
 
 #ifndef QT_NO_COMPRESS
 #include <zconf.h>
@@ -4838,6 +4841,60 @@ QByteArray QByteArray::toPercentEncoding(const QByteArray &exclude, const QByteA
     return result;
 }
 
+#if defined(Q_OS_WASM) || defined(Q_QDOC)
+
+/*!
+    \brief Constructs a new QByteArray containing a copy of the Uint8Array \a uint8array.
+
+    This function transfers data from a JavaScript data buffer - which
+    is not addressable from C++ code - to heap memory owned by a QByteArray.
+    The Uint8Array can be released once this function returns and a copy
+    has been made.
+
+    The \a uint8array argument must an emscripten::val referencing an Uint8Array
+    object, e.g. obtained from a global JavaScript variable:
+
+    \snippet code/src_corelib_text_qbytearray.cpp 55
+
+    This function returns a null QByteArray if the size of the Uint8Array
+    exceeds the maximum capacity of QByteArray, or if the \a uint8array
+    argument is not of the Uint8Array type.
+
+    \since 6.4
+    \ingroup platform-type-conversions
+
+    \sa toUint8Array()
+*/
+
+QByteArray QByteArray::fromUint8Array(emscripten::val uint8array)
+{
+    return qstdweb::Uint8Array(uint8array).copyToQByteArray();
+}
+
+/*!
+    \brief Creates a Uint8Array from a QByteArray
+
+    This function transfers data from heap memory owned by a QByteArray
+    to a JavaScript data buffer. The function allocates and copies into an
+    ArrayBuffer, and returns a Uint8Array view to that buffer.
+
+    The JavaScript objects own a copy of the data, and this
+    QByteArray can be safely deleted after the copy has been made.
+
+    \snippet code/src_corelib_text_qbytearray.cpp 56
+
+    \since 6.4
+    \ingroup platform-type-conversions
+
+    \sa toUint8Array()
+*/
+emscripten::val QByteArray::toUint8Array()
+{
+    return qstdweb::Uint8Array::copyFrom(*this).val();
+}
+
+#endif
+
 /*! \typedef QByteArray::ConstIterator
     \internal
 */
diff --git a/src/corelib/text/qbytearray.h b/src/corelib/text/qbytearray.h
index 3a57b383dc..afe234d643 100644
--- a/src/corelib/text/qbytearray.h
+++ b/src/corelib/text/qbytearray.h
@@ -34,6 +34,12 @@ Q_FORWARD_DECLARE_CF_TYPE(CFData);
 Q_FORWARD_DECLARE_OBJC_CLASS(NSData);
 #endif
 
+#if defined(Q_OS_WASM) || defined(Q_QDOC)
+namespace emscripten {
+    class val;
+}
+#endif
+
 QT_BEGIN_NAMESPACE
 
 class QString;
@@ -387,6 +393,11 @@ public:
     NSData *toRawNSData() const Q_DECL_NS_RETURNS_AUTORELEASED;
 #endif
 
+#if defined(Q_OS_WASM) || defined(Q_QDOC)
+    static QByteArray fromUint8Array(emscripten::val uint8array);
+    emscripten::val toUint8Array();
+#endif
+
     typedef char *iterator;
     typedef const char *const_iterator;
     typedef iterator Iterator;