Merge pull request #69 from pixilation/fix-clobbered-e-variable

Fix 'e' variable being clobbered by watch exception

Author: softwareCobbler

luceedebug/src/main/java/luceedebug/coreinject/ExprEvaluator.java

@@ -43,12 +43,13 @@ static abstract class Evaluator {
         // At this time, `lucee.runtime.compiler.Renderer.loadPage` will
         // cache compilations based on the hash of the source text; so, using the same result name
         // every time ensures we don't need to recompile a particular expression every time.
+        static protected final String errName = "__luceedebug__error";
         static protected final String resultName = "__luceedebug__evalResult";
         static protected String getEvaluatableSourceText(String expr) {
             return ""
                 + "<cfscript>"
                 + "try { variables['" + resultName + "'] = {'ok': true, 'result': " + expr + " } }"
-                + "catch (any e) { variables['" + resultName + "'] = {'ok': false, 'result': e.message } }"
+                + "catch (any " + errName + ") { variables['" + resultName + "'] = {'ok': false, 'result': " + errName + ".message } }"
                 + "</cfscript>";
         }
 

luceedebug/src/test/java/luceedebug/EvaluatesAnExpression.java

@@ -66,7 +66,7 @@ void a(LuceeAndDockerInfo dockerInfo) throws Throwable {
             DapUtils.attach(dapServer).join();
 
             DapUtils
-                .setBreakpoints(dapServer, "/var/www/a.cfm", 3)
+                .setBreakpoints(dapServer, "/var/www/a.cfm", 4)
                 .join();
 
             final var requestThreadToBeBlockedByBreakpoint = new java.lang.Thread(() -> {
@@ -104,6 +104,21 @@ void a(LuceeAndDockerInfo dockerInfo) throws Throwable {
                 "evaluation result as expected"
             );
 
+            assertEquals(
+                "\"bar\"",
+                DapUtils.evaluate(dapServer, frameID, "e").join().getResult(),
+                "e is initialized to \"bar\""
+            );
+
+            // An expression that will throw an exception, should not clobber "e" in the local scope
+            DapUtils.evaluate(dapServer, frameID, "zzz");
+
+            assertEquals(
+                "\"bar\"",
+                DapUtils.evaluate(dapServer, frameID, "e").join().getResult(),
+                "e is still \"bar\""
+            );
+
             DapUtils.continue_(dapServer, threadID);
 
             requestThreadToBeBlockedByBreakpoint.join();

test/docker/app1/a.cfm

@@ -1,5 +1,6 @@
 <cfscript>
     function foo(n) {
+        var e = "bar";
         return n;
     }