1 files changed, 75 insertions, 23 deletions

diff --git a/ext/console/02_console.js b/ext/console/02_console.js
index 4dab799b9..d3734b6a4 100644
--- a/ext/console/02_console.js
+++ b/ext/console/02_console.js
@@ -72,6 +72,7 @@
     ArrayPrototypePop,
     ArrayPrototypeSort,
     ArrayPrototypeSlice,
+    ArrayPrototypeShift,
     ArrayPrototypeIncludes,
     ArrayPrototypeFill,
     ArrayPrototypeFilter,
@@ -340,11 +341,17 @@
     // If we didn't find any properties, we will just append an
     // empty suffix.
     let suffix = ``;
+    let refStr = "";
     if (
       ObjectKeys(value).length > 0 ||
       ObjectGetOwnPropertySymbols(value).length > 0
     ) {
-      const propString = inspectRawObject(value, level, inspectOptions);
+      const [propString, refIndex] = inspectRawObject(
+        value,
+        level,
+        inspectOptions,
+      );
+      refStr = refIndex;
       // Filter out the empty string for the case we only have
       // non-enumerable symbols.
       if (
@@ -357,9 +364,9 @@
 
     if (value.name && value.name !== "anonymous") {
       // from MDN spec
-      return cyan(`[${cstrName}: ${value.name}]`) + suffix;
+      return cyan(`${refStr}[${cstrName}: ${value.name}]`) + suffix;
     }
-    return cyan(`[${cstrName}]`) + suffix;
+    return cyan(`${refStr}[${cstrName}]`) + suffix;
   }
 
   function inspectIterable(
@@ -589,6 +596,23 @@
     return entries;
   }
 
+  let circular;
+  function handleCircular(value, cyan) {
+    let index = 1;
+    if (circular === undefined) {
+      circular = new Map();
+      MapPrototypeSet(circular, value, index);
+    } else {
+      index = MapPrototypeGet(circular, value);
+      if (index === undefined) {
+        index = circular.size + 1;
+        MapPrototypeSet(circular, value, index);
+      }
+    }
+    // Circular string is cyan
+    return cyan(`[Circular *${index}]`);
+  }
+
   function _inspectValue(
     value,
     level,
@@ -623,7 +647,7 @@
       case "function": // Function string is cyan
         if (ctxHas(value)) {
           // Circular string is cyan
-          return cyan("[Circular]");
+          return handleCircular(value, cyan);
         }
 
         return inspectFunction(value, level, inspectOptions);
@@ -633,8 +657,7 @@
         }
 
         if (ctxHas(value)) {
-          // Circular string is cyan
-          return cyan("[Circular]");
+          return handleCircular(value, cyan);
         }
         return inspectObject(value, level, inspectOptions);
       default:
@@ -892,25 +915,41 @@
     return red(RegExpPrototypeToString(value)); // RegExps are red
   }
 
-  function inspectError(value) {
-    const causes = [];
+  function inspectError(value, cyan) {
+    const causes = [value];
 
     let err = value;
-    while (
-      ObjectPrototypeIsPrototypeOf(ErrorPrototype, err.cause) &&
-      err.cause !== value &&
-      !ArrayPrototypeIncludes(causes, err.cause) // circular check
-    ) {
-      ArrayPrototypePush(causes, err.cause);
-      err = err.cause;
+    while (err.cause) {
+      if (ArrayPrototypeIncludes(causes, err.cause)) {
+        ArrayPrototypePush(causes, handleCircular(err.cause, cyan));
+        break;
+      } else {
+        ArrayPrototypePush(causes, err.cause);
+        err = err.cause;
+      }
     }
 
-    return `${value.stack}${
+    const refMap = new Map();
+    for (const cause of causes) {
+      if (circular !== undefined) {
+        const index = MapPrototypeGet(circular, cause);
+        if (index !== undefined) {
+          MapPrototypeSet(refMap, cause, cyan(`<ref *${index}> `));
+        }
+      }
+    }
+    ArrayPrototypeShift(causes);
+
+    return (MapPrototypeGet(refMap, value) ?? "") + value.stack +
       ArrayPrototypeJoin(
-        ArrayPrototypeMap(causes, (cause) => `\nCaused by ${cause.stack}`),
+        ArrayPrototypeMap(
+          causes,
+          (cause) =>
+            "\nCaused by " + (MapPrototypeGet(refMap, cause) ?? "") +
+            (cause?.stack ?? cause),
+        ),
         "",
-      )
-    }`;
+      );
   }
 
   function inspectStringObject(value, inspectOptions) {
@@ -1002,7 +1041,7 @@
     const cyan = maybeColor(colors.cyan, inspectOptions);
 
     if (level >= inspectOptions.depth) {
-      return cyan("[Object]"); // wrappers are in cyan
+      return [cyan("[Object]"), ""]; // wrappers are in cyan
     }
 
     let baseString;
@@ -1144,7 +1183,15 @@
       baseString = `${displayName} ${baseString}`;
     }
 
-    return baseString;
+    let refIndex = "";
+    if (circular !== undefined) {
+      const index = MapPrototypeGet(circular, value);
+      if (index !== undefined) {
+        refIndex = `<ref *${index}> `;
+      }
+    }
+
+    return [baseString, refIndex];
   }
 
   function inspectObject(
@@ -1171,7 +1218,7 @@
       return String(value[privateCustomInspect](inspect));
     }
     if (ObjectPrototypeIsPrototypeOf(ErrorPrototype, value)) {
-      return inspectError(value);
+      return inspectError(value, maybeColor(colors.cyan, inspectOptions));
     } else if (ArrayIsArray(value)) {
       return inspectArray(value, level, inspectOptions);
     } else if (ObjectPrototypeIsPrototypeOf(NumberPrototype, value)) {
@@ -1207,7 +1254,9 @@
       );
     } else {
       // Otherwise, default object formatting
-      return inspectRawObject(value, level, inspectOptions);
+      let [insp, refIndex] = inspectRawObject(value, level, inspectOptions);
+      insp = refIndex + insp;
+      return insp;
     }
   }
 
@@ -1660,6 +1709,8 @@
   }
 
   function inspectArgs(args, inspectOptions = {}) {
+    circular = undefined;
+
     const noColor = colors.getNoColor();
     const rInspectOptions = { ...DEFAULT_INSPECT_OPTIONS, ...inspectOptions };
     const first = args[0];
@@ -2076,6 +2127,7 @@
     value,
     inspectOptions = {},
   ) {
+    circular = undefined;
     return inspectValue(value, 0, {
       ...DEFAULT_INSPECT_OPTIONS,
       ...inspectOptions,