1 files changed, 309 insertions, 0 deletions
diff --git a/mailnews/base/util/errUtils.js b/mailnews/base/util/errUtils.js
new file mode 100644
index 000000000..21b205b82
--- /dev/null
+++ b/mailnews/base/util/errUtils.js
@@ -0,0 +1,309 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This file contains helper methods for debugging -- things like logging
+ * exception objects, dumping DOM nodes, Events, and generic object dumps.
+ */
+
+this.EXPORTED_SYMBOLS = ["logObject", "logException", "logElement", "logEvent",
+                          "errorWithDebug"];
+
+/**
+ * Report on an object to stdout.
+ * @param aObj  the object to be dumped
+ * @param aName the name of the object, for informational purposes
+ */
+function logObject(aObj, aName) {
+  dump("Dumping Object: " + aName + "\n");
+  stringifier.dumpObj(aObj, aName);
+}
+
+/**
+ * Log an exception to stdout. This function should not be called in
+ * expected circumstances.
+ * @param aException  the exception to log
+ * @param [aRethrow]  set to true to rethrow the exception after logging
+ * @param [aMsg]      optional message to log
+ */
+function logException(aException, aRethrow, aMsg) {
+  stringifier.dumpException(aException, aMsg);
+
+  if (aMsg)
+    Components.utils.reportError(aMsg);
+  Components.utils.reportError(aException);
+
+  if (aRethrow)
+    throw aException;
+}
+
+/**
+ * Log an DOM element to stdout.
+ * @param aElement the DOM element to dump
+ */
+function logElement(aElement) {
+  stringifier.dumpDOM(aElement);
+}
+
+/**
+ * Log an DOM event to stdout.
+ * @param aEvent the DOM event object to dump
+ */
+function logEvent(aEvent) {
+  stringifier.dumpEvent(aEvent);
+}
+
+/**
+ * Dump the current stack and return an Error suitable for throwing.  We return
+ *  the new Error so that your code can use a "throw" statement which makes it
+ *  obvious to syntactic analysis that there is an exit occuring at that point.
+ *
+ * Example:
+ *   throw errorWithDebug("I did not expect this!");
+ *
+ * @param aString The message payload for the exception.
+ */
+function errorWithDebug(aString) {
+  dump("PROBLEM: " + aString + "\n");
+  dump("CURRENT STACK (and throwing):\n");
+  // skip this frame.
+  dump(stringifier.getStack(1));
+  return new Error(aString);
+}
+
+function Stringifier() {};
+
+Stringifier.prototype = {
+  dumpObj: function (o, name) {
+    this._reset();
+    this._append(this.objectTreeAsString(o, true, true, 0));
+    dump(this._asString());
+  },
+
+  dumpDOM: function(node, level, recursive) {
+    this._reset();
+    let s = this.DOMNodeAsString(node, level, recursive);
+    dump(s);
+  },
+
+  dumpEvent: function(event) {
+    dump(this.eventAsString(event));
+  },
+
+  dumpException: function(exc, message) {
+    dump(exc + "\n");
+    this._reset();
+    if (message)
+      this._append("Exception (" + message + ")\n");
+
+    this._append("-- Exception object --\n");
+    this._append(this.objectTreeAsString(exc));
+    if (exc.stack) {
+      this._append("-- Stack Trace --\n");
+      this._append(exc.stack); // skip dumpException and logException
+    }
+    dump(this._asString());
+  },
+
+  _reset: function() {
+    this._buffer = [];
+  },
+
+  _append: function(string) {
+    this._buffer.push(string);
+  },
+
+  _asString: function() {
+    let str = this._buffer.join('');
+    this._reset();
+    return str;
+  },
+
+  getStack: function(skipCount) {
+    if (!((typeof Components == "object") &&
+          (typeof Components.classes == "object")))
+      return "No stack trace available.";
+    if (typeof(skipCount) === undefined)
+      skipCount = 0;
+
+    let frame = Components.stack.caller;
+    let str = "<top>";
+
+    while (frame) {
+      if (skipCount > 0) {
+        // Skip this frame.
+        skipCount -= 1;
+      }
+      else {
+        // Include the data from this frame.
+        let name = frame.name ? frame.name : "[anonymous]";
+        str += "\n" + name + "@" + frame.filename + ':' + frame.lineNumber;
+      }
+      frame = frame.caller;
+    }
+    return str + "\n";
+  },
+
+  objectTreeAsString: function(o, recurse, compress, level) {
+    let s = "";
+    if (recurse === undefined)
+      recurse = 0;
+    if (level === undefined)
+      level = 0;
+    if (compress === undefined)
+      compress = true;
+    let pfx = "";
+
+    for (var junk = 0; junk < level; junk++)
+      pfx += (compress) ? "| " : "|  ";
+
+    let tee = (compress) ? "+ " : "+- ";
+
+    if (typeof(o) != "object") {
+      s += pfx + tee + " (" + typeof(o) + ") " + o + "\n";
+    }
+    else {
+      for (let i in o) {
+        try {
+          let t = typeof o[i];
+          switch (t) {
+            case "function":
+              let sfunc = String(o[i]).split("\n");
+              if (sfunc[2] == "    [native code]")
+                sfunc = "[native code]";
+              else
+                sfunc = sfunc.length + " lines";
+              s += pfx + tee + i + " (function) " + sfunc + "\n";
+              break;
+            case "object":
+              s += pfx + tee + i + " (object) " + o[i] + "\n";
+              if (!compress)
+                s += pfx + "|\n";
+              if ((i != "parent") && (recurse))
+                s += this.objectTreeAsString(o[i], recurse - 1,
+                                             compress, level + 1);
+              break;
+            case "string":
+              if (o[i].length > 200)
+                s += pfx + tee + i + " (" + t + ") " + o[i].length + " chars\n";
+              else
+                s += pfx + tee + i + " (" + t + ") '" + o[i] + "'\n";
+              break;
+            default:
+              s += pfx + tee + i + " (" + t + ") " + o[i] + "\n";
+          }
+        } catch (ex) {
+          s += pfx + tee + " (exception) " + ex + "\n";
+        }
+        if (!compress)
+          s += pfx + "|\n";
+      }
+    }
+    s += pfx + "*\n";
+    return s;
+  },
+
+  _repeatStr: function (str, aCount) {
+    let res = "";
+    while (--aCount >= 0)
+      res += str;
+    return res;
+  },
+
+  DOMNodeAsString: function(node, level, recursive) {
+    if (level === undefined)
+      level = 0
+    if (recursive === undefined)
+      recursive = true;
+    this._append(this._repeatStr(" ", 2*level) + "<" + node.nodeName + "\n");
+
+    if (node.nodeType == 3) {
+        this._append(this._repeatStr(" ", (2*level) + 4) + node.nodeValue + "'\n");
+    }
+    else {
+      if (node.attributes) {
+        for (let i = 0; i < node.attributes.length; i++) {
+          this._append(this._repeatStr(
+                         " ", (2*level) + 4) + node.attributes[i].nodeName +
+                         "='" + node.attributes[i].nodeValue + "'\n");
+        }
+      }
+      if (node.childNodes.length == 0) {
+        this._append(this._repeatStr(" ", (2*level)) + "/>\n");
+      }
+      else if (recursive) {
+        this._append(this._repeatStr(" ", (2*level)) + ">\n");
+        for (let i = 0; i < node.childNodes.length; i++) {
+          this._append(this.DOMNodeAsString(node.childNodes[i], level + 1));
+        }
+        this._append(this._repeatStr(" ", 2*level) + "</" + node.nodeName + ">\n");
+      }
+    }
+    return this._asString();
+  },
+
+  eventAsString: function (event) {
+    this._reset();
+    this._append("-EVENT --------------------------\n");
+    this._append("type:           " + event.type + "\n");
+    this._append("eventPhase:     " + event.eventPhase + "\n");
+    if ("charCode" in event) {
+      this._append("charCode: " + event.charCode + "\n");
+      if ("name" in event)
+        this._append("str(charCode):  '" + String.fromCharCode(event.charCode) + "'\n");
+    }
+    if (("target" in event) && event.target) {
+      this._append("target: " + event.target + "\n");
+      if ("nodeName" in event.target)
+        this._append("target.nodeName: " + event.target.nodeName + "\n");
+      if ("getAttribute" in event.target)
+        this._append("target.id: " + event.target.getAttribute("id") + "\n");
+    }
+    if (("currentTarget" in event) && event.currentTarget) {
+      this._append("currentTarget: " + event.currentTarget + "\n");
+      if ("nodeName" in event.currentTarget)
+        this._append("currentTarget.nodeName: "+ event.currentTarget.nodeName + "\n");
+      if ("getAttribute" in event.currentTarget)
+        this._append("currentTarget.id: "+ event.currentTarget.getAttribute("id") + "\n");
+    }
+    if (("originalTarget" in event) && event.originalTarget) {
+      this._append("originalTarget: " + event.originalTarget + "\n");
+      if ("nodeName" in event.originalTarget)
+        this._append("originalTarget.nodeName: "+ event.originalTarget.nodeName + "\n");
+      if ("getAttribute" in event.originalTarget)
+        this._append("originalTarget.id: "+ event.originalTarget.getAttribute("id") + "\n");
+    }
+    let names = [
+        "bubbles",
+        "cancelable",
+        "detail",
+        "button",
+        "keyCode",
+        "isChar",
+        "shiftKey",
+        "altKey",
+        "ctrlKey",
+        "metaKey",
+        "clientX",
+        "clientY",
+        "screenX",
+        "screenY",
+        "layerX",
+        "layerY",
+        "isTrusted",
+        "timeStamp",
+        "currentTargetXPath",
+        "targetXPath",
+        "originalTargetXPath"
+                ];
+    for (let i in names) {
+      if (names[i] in event)
+        this._append(names[i] + ": " + event[names[i]] + "\n");
+    }
+    this._append("-------------------------------------\n");
+    return this._asString();
+  }
+};
+
+var stringifier = new Stringifier();