Bug 906139 - Preserve unknown fields found in downloads.json. r=paolo

toolkit/components/jsdownloads/src/DownloadCore.jsm

@@ -92,6 +92,36 @@ function isString(aValue) {
          (typeof aValue == "object" && "charAt" in aValue);
 }
 
+/**
+ * Serialize the unknown properties of aObject into aSerializable.
+ */
+function serializeUnknownProperties(aObject, aSerializable)
+{
+  if (aObject._unknownProperties) {
+    for (let property in aObject._unknownProperties) {
+      aSerializable[property] = aObject._unknownProperties[property];
+    }
+  }
+}
+
+/**
+ * Check for any unknown properties in aSerializable and preserve those in the
+ * _unknownProperties field of aObject. aFilterFn is called for each property
+ * name of aObject and should return true only for unknown properties.
+ */
+function deserializeUnknownProperties(aObject, aSerializable, aFilterFn)
+{
+  for (let property in aSerializable) {
+    if (aFilterFn(property)) {
+      if (!aObject._unknownProperties) {
+        aObject._unknownProperties = { };
+      }
+
+      aObject._unknownProperties[property] = aSerializable[property];
+    }
+  }
+}
+
 /**
  * This determines the minimum time interval between updates to the number of
  * bytes transferred, and is a limiting factor to the sequence of readings used
@@ -838,11 +868,13 @@ Download.prototype = {
 
     // These are serialized unless they are false, null, or empty strings.
     for (let property of kSerializableDownloadProperties) {
-      if (property != "error" && this[property]) {
+      if (property != "error" && property != "startTime" && this[property]) {
         serializable[property] = this[property];
       }
     }
 
+    serializeUnknownProperties(this, serializable);
+
     return serializable;
   },
 
@@ -933,6 +965,13 @@ Download.fromSerializable = function (aSerializable) {
     }
   }
 
+  deserializeUnknownProperties(download, aSerializable, property =>
+    kSerializableDownloadProperties.indexOf(property) == -1 &&
+    property != "startTime" &&
+    property != "source" &&
+    property != "target" &&
+    property != "saver");
+
   return download;
 };
 
@@ -971,7 +1010,7 @@ DownloadSource.prototype = {
   toSerializable: function ()
   {
     // Simplify the representation if we don't have other details.
-    if (!this.isPrivate && !this.referrer) {
+    if (!this.isPrivate && !this.referrer && !this._unknownProperties) {
       return this.url;
     }
 
@@ -982,6 +1021,8 @@ DownloadSource.prototype = {
     if (this.referrer) {
       serializable.referrer = this.referrer;
     }
+
+    serializeUnknownProperties(this, serializable);
     return serializable;
   },
 };
@@ -1020,7 +1061,11 @@ DownloadSource.fromSerializable = function (aSerializable) {
     if ("referrer" in aSerializable) {
       source.referrer = aSerializable.referrer;
     }
+
+    deserializeUnknownProperties(source, aSerializable, property =>
+      property != "url" && property != "isPrivate" && property != "referrer");
   }
+
   return source;
 };
 
@@ -1054,12 +1099,14 @@ DownloadTarget.prototype = {
   toSerializable: function ()
   {
     // Simplify the representation if we don't have other details.
-    if (!this.partFilePath) {
+    if (!this.partFilePath && !this._unknownProperties) {
       return this.path;
     }
 
-    return { path: this.path,
-             partFilePath: this.partFilePath };
+    let serializable = { path: this.path,
+                         partFilePath: this.partFilePath };
+    serializeUnknownProperties(this, serializable);
+    return serializable;
   },
 };
 
@@ -1072,6 +1119,7 @@ DownloadTarget.prototype = {
  *        object with the following properties:
  *        {
  *          path: String containing the path of the target file.
+ *          partFilePath: optional string containing the part file path.
  *        }
  *
  * @return The newly created DownloadTarget object.
@@ -1091,6 +1139,9 @@ DownloadTarget.fromSerializable = function (aSerializable) {
     if ("partFilePath" in aSerializable) {
       target.partFilePath = aSerializable.partFilePath;
     }
+
+    deserializeUnknownProperties(target, aSerializable, property =>
+      property != "path" && property != "partFilePath");
   }
   return target;
 };
@@ -1598,12 +1649,14 @@ DownloadCopySaver.prototype = {
   toSerializable: function ()
   {
     // Simplify the representation if we don't have other details.
-    if (!this.entityID) {
+    if (!this.entityID && !this._unknownProperties) {
       return "copy";
     }
 
-    return { type: "copy",
-             entityID: this.entityID };
+    let serializable = { type: "copy",
+                         entityID: this.entityID };
+    serializeUnknownProperties(this, serializable);
+    return serializable;
   },
 };
 
@@ -1621,6 +1674,10 @@ DownloadCopySaver.fromSerializable = function (aSerializable) {
   if ("entityID" in aSerializable) {
     saver.entityID = aSerializable.entityID;
   }
+
+  deserializeUnknownProperties(saver, aSerializable, property =>
+    property != "entityID" && property != "type");
+
   return saver;
 };
 

toolkit/components/jsdownloads/test/unit/test_DownloadStore.js

@@ -215,3 +215,78 @@ add_task(function test_load_string_malformed()
 
   do_check_eq(items.length, 0);
 });
+
+/**
+ * Saves downloads with unknown properties to a file and then reloads
+ * them to ensure that these properties are preserved.
+ */
+add_task(function test_save_reload_unknownProperties()
+{
+  let [listForSave, storeForSave] = yield promiseNewListAndStore();
+  let [listForLoad, storeForLoad] = yield promiseNewListAndStore(
+                                                 storeForSave.path);
+
+  let download1 = yield promiseNewDownload(httpUrl("source.txt"));
+  // startTime should be ignored as it is a known property, and error
+  // is ignored by serialization
+  download1._unknownProperties = { peanut: "butter",
+                                   orange: "marmalade",
+                                   startTime: 77,
+                                   error: { message: "Passed" } };
+  listForSave.add(download1);
+
+  let download2 = yield promiseStartLegacyDownload();
+  yield download2.cancel();
+  download2._unknownProperties = { number: 5, object: { test: "string" } };
+  listForSave.add(download2);
+
+  let download3 = yield Downloads.createDownload({
+    source: { url: httpUrl("empty.txt"),
+              referrer: TEST_REFERRER_URL,
+              source1: "download3source1",
+              source2: "download3source2" },
+    target: { path: getTempFile(TEST_TARGET_FILE_NAME).path,
+              target1: "download3target1",
+              target2: "download3target2" },
+    saver : { type: "copy",
+              saver1: "download3saver1",
+              saver2: "download3saver2" },
+  });
+  listForSave.add(download3);
+
+  yield storeForSave.save();
+  yield storeForLoad.load();
+
+  let itemsForSave = yield listForSave.getAll();
+  let itemsForLoad = yield listForLoad.getAll();
+
+  do_check_eq(itemsForSave.length, itemsForLoad.length);
+
+  do_check_eq(Object.keys(itemsForLoad[0]._unknownProperties).length, 2);
+  do_check_eq(itemsForLoad[0]._unknownProperties.peanut, "butter");
+  do_check_eq(itemsForLoad[0]._unknownProperties.orange, "marmalade");
+  do_check_false("startTime" in itemsForLoad[0]._unknownProperties);
+  do_check_false("error" in itemsForLoad[0]._unknownProperties);
+
+  do_check_eq(Object.keys(itemsForLoad[1]._unknownProperties).length, 2);
+  do_check_eq(itemsForLoad[1]._unknownProperties.number, 5);
+  do_check_eq(itemsForLoad[1]._unknownProperties.object.test, "string");
+
+  do_check_eq(Object.keys(itemsForLoad[2].source._unknownProperties).length, 2);
+  do_check_eq(itemsForLoad[2].source._unknownProperties.source1,
+              "download3source1");
+  do_check_eq(itemsForLoad[2].source._unknownProperties.source2,
+              "download3source2");
+
+  do_check_eq(Object.keys(itemsForLoad[2].target._unknownProperties).length, 2);
+  do_check_eq(itemsForLoad[2].target._unknownProperties.target1,
+              "download3target1");
+  do_check_eq(itemsForLoad[2].target._unknownProperties.target2,
+              "download3target2");
+
+  do_check_eq(Object.keys(itemsForLoad[2].saver._unknownProperties).length, 2);
+  do_check_eq(itemsForLoad[2].saver._unknownProperties.saver1,
+              "download3saver1");
+  do_check_eq(itemsForLoad[2].saver._unknownProperties.saver2,
+              "download3saver2");
+});