__tests__/monitor.test.js

@@ -482,4 +482,26 @@ describe("monitorConsole", () => {
     // We expect it to have called api.time fewer than 10 times (excluding the startTick call)
     expect(api.time.mock.calls.length).toBeLessThan(10);
   });
+
+  it("detects encoded tracebacks in log lines", async () => {
+    const api = buildMockApi({ ticks: [100, 101, 102] });
+    setTimeout(() => {
+      api._fireConsole({
+        messages: {
+          log: [
+            "Error: ReferenceError: a is not defined%0A    at eval (eval at <anonymous> (_console1778948572008_0:1:46), <anonymous>:1:1)%0A    at _console1778948572008_0:1:46",
+          ],
+          results: [],
+        },
+        error: null,
+      });
+    }, 50);
+
+    const result = await monitorConsole(api, {
+      ...BASE_OPTS,
+      onTraceback: "fail",
+    });
+    expect(result.sawTraceback).toBe(true);
+    expect(result.sawErrorLog).toBe(true);
+  });
 });

monitor.js

@@ -51,7 +51,8 @@ export function buildSubscribePath(hostname, shard) {
  */
 export function detectTraceback(errorText) {
   if (!errorText) return false;
-  return /^\s{4}at /m.test(errorText);
+  const text = safeDecode(errorText);
+  return /^\s{4}at /m.test(text);
 }
 
 /**
@@ -67,6 +68,22 @@ export function detectWarning(logLines) {
   return logLines.some((line) => warnPattern.test(line));
 }
 
+/**
+ * Safely decodes a URI-encoded string from the Screeps console.
+ * Returns the original string if decoding fails or if no '%' is present.
+ *
+ * @param {string} text
+ * @returns {string}
+ */
+export function safeDecode(text) {
+  if (typeof text !== "string" || !text.includes("%")) return text;
+  try {
+    return decodeURIComponent(text);
+  } catch (err) {
+    return text;
+  }
+}
+
 // ────────────────────────────────────────────────────────────────────────────
 // Output helpers
 // ────────────────────────────────────────────────────────────────────────────
@@ -166,11 +183,19 @@ export function handleConsoleEvent(event, opts, stdoutBuffer, state) {
   if (detectWarning(logLines)) {
     state.sawWarningLog = true;
     const warnPattern = /<font\s+color=['"](?:orange|yellow)['"]/i;
-    logLines.filter((l) => warnPattern.test(l)).forEach((l) => core.warning(l));
+    logLines
+      .filter((l) => warnPattern.test(l))
+      .forEach((l) => core.warning(safeDecode(l)));
+  }
+
+  // ── Traceback detection in log lines (Screeps sometimes sends errors here) ─
+  if (logLines.some((l) => detectTraceback(l))) {
+    state.sawTraceback = true;
+    state.sawErrorLog = true;
   }
 
   // ── Stdout lines ──────────────────────────────────────────────────────────
-  const allStdout = [...logLines, ...results];
+  const allStdout = [...logLines, ...results].map(safeDecode);
   if (allStdout.length > 0) {
     if (logToFile) {
       stdoutBuffer.push(...allStdout);
@@ -182,8 +207,9 @@ export function handleConsoleEvent(event, opts, stdoutBuffer, state) {
   // ── Error field (always live) ─────────────────────────────────────────────
   if (errorText) {
     state.sawErrorLog = true;
-    core.error(errorText);
-    if (detectTraceback(errorText)) {
+    const decodedError = safeDecode(errorText);
+    core.error(decodedError);
+    if (detectTraceback(decodedError)) {
       state.sawTraceback = true;
     }
   }

scratch/test_traceback.js

@@ -0,0 +1,12 @@
+function detectTraceback(errorText) {
+  if (!errorText) return false;
+  return /^\s{4}at /m.test(errorText);
+}
+
+const encodedTraceback =
+  "Error: ReferenceError: a is not defined%0A    at eval (eval at <anonymous> (_console1778948572008_0:1:46), <anonymous>:1:1)%0A    at _console1778948572008_0:1:46%0A    at _console1778948572008_0:1:60%0A    at exports.evalCode (<runtime>:15347:63)%0A    at exports.run (<runtime>:20876:41)%0A";
+
+console.log("Encoded match:", detectTraceback(encodedTraceback));
+
+const decodedTraceback = decodeURIComponent(encodedTraceback);
+console.log("Decoded match:", detectTraceback(decodedTraceback));