fix(reporter): split err.stack at trailing frame block so embedded stacks render once

Author: mostafaNazari702

lib/reporters/base.mjs

@@ -402,38 +402,65 @@ var getFullErrorStack = function (err, seen) {
   }
 
   var message;
+  var usedInspect = false;
 
   if (typeof err.inspect === "function") {
     message = err.inspect() + "";
+    usedInspect = true;
   } else if (err.message && typeof err.message.toString === "function") {
     message = err.message + "";
   } else {
     message = "";
   }
 
-  var msg;
-  var stack = err.stack || message;
-  var index = message ? stack.indexOf(message) : -1;
+  var rawStack = err.stack || message;
+  var lines = rawStack.split("\n");
+  var lastLine = lines.length - 1;
+  while (lastLine >= 0 && lines[lastLine] === "") {
+    lastLine--;
+  }
+  var frameStart = lastLine + 1;
+  for (var i = lastLine; i >= 0; i--) {
+    if (/^\s+at\s/.test(lines[i])) {
+      frameStart = i;
+    } else {
+      break;
+    }
+  }
 
-  if (index === -1) {
-    msg = message;
+  var msg;
+  var stack;
+  var splitSucceeded = false;
+  if (frameStart <= lastLine) {
+    stack = lines.slice(frameStart, lastLine + 1).join("\n");
+    msg =
+      usedInspect || frameStart === 0
+        ? message
+        : lines.slice(0, frameStart).join("\n");
+    splitSucceeded = true;
   } else {
-    index += message.length;
-    msg = stack.slice(0, index);
-    // remove msg from stack
-    stack = stack.slice(index + 1);
-
-    if (err.cause) {
-      seen = seen || new Set();
-      seen.add(err);
-      const causeStack = getFullErrorStack(err.cause, seen);
-      stack +=
-        "\n   Caused by: " +
-        causeStack.msg +
-        (causeStack.stack ? "\n" + causeStack.stack : "");
+    var index = message ? rawStack.indexOf(message) : -1;
+    if (index === -1) {
+      msg = message;
+      stack = rawStack;
+    } else {
+      index += message.length;
+      msg = rawStack.slice(0, index);
+      stack = rawStack.slice(index + 1);
+      splitSucceeded = true;
     }
   }
 
+  if (splitSucceeded && err.cause) {
+    seen = seen || new Set();
+    seen.add(err);
+    const causeStack = getFullErrorStack(err.cause, seen);
+    stack +=
+      "\n   Caused by: " +
+      causeStack.msg +
+      (causeStack.stack ? "\n" + causeStack.stack : "");
+  }
+
   return {
     message,
     msg,

test/reporters/base.spec.js

@@ -491,6 +491,66 @@ describe("Base reporter", function () {
     expect(errOut, "to be", "1) test title:\n     Error\n  foo\n  bar");
   });
 
+  describe("message and stack splitting", function () {
+    it("should render the message and frames when the stack is only frames", function () {
+      var err = {
+        message: "Error",
+        stack: "    at foo (foo.js:1:1)\n    at bar (bar.js:2:2)",
+        showDiff: false,
+      };
+      var test = makeTest(err);
+
+      list([test]);
+
+      var errOut = stdout.join("\n").trim();
+      expect(
+        errOut,
+        "to be",
+        "1) test title:\n     Error\n      at foo (foo.js:1:1)\n      at bar (bar.js:2:2)",
+      );
+    });
+
+    it("should not duplicate an embedded stack when the message's frames are rewritten in the stack", function () {
+      var embeddedMessage =
+        "An error occured with following trace:\n\nError\n    at inner (/original/foo.js:1:1)";
+      var rewritten = embeddedMessage.replace(/\/original\//g, "/filtered/");
+      var err = {
+        message: embeddedMessage,
+        stack: "Error: " + rewritten + "\n    at runTest (lib/runner.js:1:1)",
+        showDiff: false,
+      };
+      var test = makeTest(err);
+
+      list([test]);
+
+      var errOut = stdout.join("\n").trim();
+      expect(
+        errOut,
+        "to be",
+        "1) test title:\n     Error: An error occured with following trace:\n\nError\n      at inner (/filtered/foo.js:1:1)\n      at runTest (lib/runner.js:1:1)",
+      );
+    });
+
+    it("should split identically when the rewritten stack has a trailing newline", function () {
+      var embeddedMessage =
+        "An error occured with following trace:\n\nError\n    at inner (/original/foo.js:1:1)";
+      var rewritten = embeddedMessage.replace(/\/original\//g, "/filtered/");
+      var err = {
+        message: embeddedMessage,
+        stack: "Error: " + rewritten + "\n    at runTest (lib/runner.js:1:1)\n",
+        showDiff: false,
+      };
+      var test = makeTest(err);
+      list([test]);
+      var errOut = stdout.join("\n").trim();
+      expect(
+        errOut,
+        "to be",
+        "1) test title:\n     Error: An error occured with following trace:\n\nError\n      at inner (/filtered/foo.js:1:1)\n      at runTest (lib/runner.js:1:1)",
+      );
+    });
+  });
+
   describe("error causes", function () {
     it("should append any error cause trail to stack traces", function () {
       var err = {