Allow throw undefined to still show an exception in the REPL (fix #…

…2423)
espruino · Nov 2, 2023 · 5b7e9db · 5b7e9db
1 parent 0f1b5b0
commit 5b7e9db
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Showing 5 changed files with 11 additions and 7 deletions.
diff --git a/ChangeLog b/ChangeLog
@@ -17,6 +17,7 @@
             Bangle.js: Fix terminal's repeated call to '.flip' that broke double buffering on Bangle.js 1
             JIT: Ensure ternary block skips 'named' variables (and references them correctly)
             Fix for UNFINISHED REGEX syntax error when parsing `true / false` (fix #2424)
+            Allow `throw undefined` to still show an exception in the REPL (fix #2423)
 
      2v19 : Fix Object.values/entries for numeric keys after 2v18 regression (fix #2375)
             nRF52: for SD>5 use static buffers for advertising and scan response data (#2367)

diff --git a/src/jsinteractive.c b/src/jsinteractive.c
@@ -1206,14 +1206,16 @@ void jsiCheckErrors() {
     jsiConsolePrint("Execution Interrupted during event processing.\n");
   }
   bool reportedError = false;
+  bool hasException = (execInfo.execute & EXEC_EXCEPTION)!=0;
   JsVar *exception = jspGetException();
-  if (exception) {
+  if (hasException) {
     if (jsiExecuteEventCallbackOn("process", JS_EVENT_PREFIX"uncaughtException", 1, &exception)) {
       jsvUnLock(exception);
       exception = jspGetException();
+      if (!exception) hasException = false;
     }
   }
-  if (exception) {
+  if (hasException) {
     jsiConsoleRemoveInputLine();
     jsiConsolePrintf("Uncaught %v\n", exception);
     reportedError = true;
@@ -1224,8 +1226,8 @@ void jsiCheckErrors() {
         jsvUnLock(stackTrace);
       }
     }
-    jsvUnLock(exception);
   }
+  jsvUnLock(exception);
   if (jspIsInterrupted()
 #ifdef USE_DEBUGGER
       && !(jsiStatus & JSIS_EXIT_DEBUGGER)

diff --git a/src/jsparse.c b/src/jsparse.c
@@ -267,7 +267,7 @@ void jspSetException(JsVar *value) {
 
 }
 
-/** Return the reported exception if there was one (and clear it) */
+/** Return the reported exception if there was one (and clear it). May return undefined even if there was an exception - eg `throw undefined` */
 JsVar *jspGetException() {
   JsVar *exceptionName = jsvFindChildFromString(execInfo.hiddenRoot, JSPARSE_EXCEPTION_VAR);
   if (exceptionName) {

diff --git a/src/jsparse.h b/src/jsparse.h
@@ -55,7 +55,7 @@ bool jspHasError();
 void jspSetError(bool lineReported);
 /// We had an exception (argument is the exception's value)
 void jspSetException(JsVar *value);
-/** Return the reported exception if there was one (and clear it) */
+/** Return the reported exception if there was one (and clear it). May return undefined even if there was an exception - eg `throw undefined` */
 JsVar *jspGetException();
 /** Return a stack trace string if there was one (and clear it) */
 JsVar *jspGetStackTrace();

diff --git a/targets/linux/main.c b/targets/linux/main.c
@@ -382,12 +382,13 @@ void die(const char *txt) {
 
 int handleErrors() {
   int e = 0;
+  bool hasException = (execInfo.execute & EXEC_EXCEPTION)!=0;
   JsVar *exception = jspGetException();
-  if (exception) {
+  if (hasException) {
     jsiConsolePrintf("Uncaught %v\n", exception);
-    jsvUnLock(exception);
     e = 1;
   }
+  jsvUnLock(exception);
 
   if (jspIsInterrupted()) {
     jsiConsoleRemoveInputLine();