set 'this' correctly for Arrow Functions - #1302 (comment)

ChangeLog

@@ -41,6 +41,7 @@
             Allow STM32LL port to write 32 bits to flash at a time to bring it in line with other ports
             Allow flash writes *from* unaligned addresses on nRF52 and ESP8266 (previously this crashed the ESP8266)
             Update process.ENV.EXPORTS to bring it in line with what the compiler uses
+            Now set 'this' correctly for Arrow Functions
 
      1v95 : nRF5x: Swap to UART fifo to avoid overrun errors at high baud rates
             Ensure Exceptions/errors are reported on a blank line

src/jsparse.c

@@ -1449,6 +1449,9 @@ NO_INLINE JsVar *jspeArrowFunction(JsVar *funcVar, JsVar *a) {
 
   bool expressionOnly = lex->tk!='{';
   jspeFunctionDefinitionInternal(funcVar, expressionOnly);
+  if (execInfo.thisVar) {
+    jsvObjectSetChild(funcVar, JSPARSE_FUNCTION_THIS_NAME, execInfo.thisVar);
+  }
   return funcVar;
 }
 

tests/test_arrow_functions_this.js

@@ -0,0 +1,9 @@
+var obj = {
+  value : 42,
+  a : function() {
+    return x=>this.value+x;
+  }
+};
+
+var r = obj.a()(8);
+result = r === 50;