Bug 1188456 - Helper to deduplicate password manager logins. r=MattN

toolkit/components/passwordmgr/LoginHelper.jsm

@@ -259,6 +259,43 @@ this.LoginHelper = {
     return newLogin;
   },
 
+  /**
+   * Removes duplicates from a list of logins.
+   *
+   * @param {nsILoginInfo[]} logins
+   *        A list of logins we want to deduplicate.
+   *
+   * @param {string[] = ["username", "password"]} uniqueKeys
+   *        A list of login attributes to use as unique keys for the deduplication.
+   *
+   * @returns {nsILoginInfo[]} list of unique logins.
+   */
+  dedupeLogins(logins, uniqueKeys = ["username", "password"]) {
+    const KEY_DELIMITER = ":";
+
+    // Generate a unique key string from a login.
+    function getKey(login, uniqueKeys) {
+      return uniqueKeys.reduce((prev, key) => prev + KEY_DELIMITER + login[key], "");
+    }
+
+    // We use a Map to easily lookup logins by their unique keys.
+    let loginsByKeys = new Map();
+    for (let login of logins) {
+      let key = getKey(login, uniqueKeys);
+      // If we find a more recently used login for the same key, replace the existing one.
+      if (loginsByKeys.has(key)) {
+        let loginDate = login.QueryInterface(Ci.nsILoginMetaInfo).timeLastUsed;
+        let storedLoginDate = loginsByKeys.get(key).QueryInterface(Ci.nsILoginMetaInfo).timeLastUsed;
+        if (loginDate < storedLoginDate) {
+          continue;
+        }
+      }
+      loginsByKeys.set(key, login);
+    }
+    // Return the map values in the form of an array.
+    return [...loginsByKeys.values()];
+  },
+
   /**
    * Open the password manager window.
    *

toolkit/components/passwordmgr/test/unit/head.js

@@ -17,6 +17,7 @@ const { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/LoginRecipes.jsm");
+Cu.import("resource://gre/modules/LoginHelper.jsm");
 
 XPCOMUtils.defineLazyModuleGetter(this, "DownloadPaths",
                                   "resource://gre/modules/DownloadPaths.jsm");

toolkit/components/passwordmgr/test/unit/test_logins_change.js

@@ -52,6 +52,29 @@ function checkLoginInvalid(aLoginInfo, aExpectedError)
   Services.logins.removeLogin(testLogin);
 }
 
+/**
+ * Verifies that two objects are not the same instance
+ * but have equal attributes.
+ *
+ * @param {Object} objectA
+ *        An object to compare.
+ *
+ * @param {Object} objectB
+ *        Another object to compare.
+ *
+ * @param {string[]} attributes
+ *        Attributes to compare.
+ *
+ * @return true if all passed attributes are equal for both objects, false otherwise.
+ */
+function compareAttributes(objectA, objectB, attributes) {
+  // If it's the same object, we want to return false.
+  if (objectA == objectB) {
+    return false;
+  }
+  return attributes.every(attr => objectA[attr] == objectB[attr]);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 //// Tests
 
@@ -295,3 +318,69 @@ add_task(function test_modifyLogin_nsIProperyBag()
 
   LoginTestUtils.clearData();
 });
+
+/**
+ * Tests the login deduplication function.
+ */
+add_task(function test_deduplicate_logins() {
+  // Different key attributes combinations and the amount of unique
+  // results expected for the TestData login list.
+  let keyCombinations = [
+    {
+      keyset: ["username", "password"],
+      results: 13,
+    },
+    {
+      keyset: ["hostname", "username"],
+      results: 17,
+    },
+    {
+      keyset: ["hostname", "username", "password"],
+      results: 18,
+    },
+    {
+      keyset: ["hostname", "username", "password", "formSubmitURL"],
+      results: 22,
+    },
+  ];
+
+  let logins = TestData.loginList();
+
+  for (let testCase of keyCombinations) {
+    // Deduplicate the logins using the current testcase keyset.
+    let deduped = LoginHelper.dedupeLogins(logins, testCase.keyset);
+    Assert.equal(deduped.length, testCase.results, "Correct amount of results.");
+
+    // Checks that every login after deduping is unique.
+    Assert.ok(deduped.every(loginA =>
+      deduped.every(loginB => !compareAttributes(loginA, loginB, testCase.keyset))
+    ), "Every login is unique.");
+  }
+});
+
+/**
+ * Ensure that the login deduplication function keeps the most recent login.
+ */
+add_task(function test_deduplicate_keeps_most_recent() {
+  // Logins to deduplicate.
+  let logins = [
+    TestData.formLogin({timeLastUsed: Date.UTC(2004, 11, 4, 0, 0, 0)}),
+    TestData.formLogin({formSubmitURL: "http://example.com", timeLastUsed: Date.UTC(2015, 11, 4, 0, 0, 0)}),
+  ];
+
+  // Deduplicate the logins.
+  let deduped = LoginHelper.dedupeLogins(logins);
+  Assert.equal(deduped.length, 1, "Deduplicated the logins array.");
+
+  // Verify that the remaining login have the most recent date.
+  let loginTimeLastUsed = deduped[0].QueryInterface(Ci.nsILoginMetaInfo).timeLastUsed;
+  Assert.equal(loginTimeLastUsed, Date.UTC(2015, 11, 4, 0, 0, 0), "Most recent login was kept.");
+
+  // Deduplicate the reverse logins array.
+  deduped = LoginHelper.dedupeLogins(logins.reverse());
+  Assert.equal(deduped.length, 1, "Deduplicated the reversed logins array.");
+
+  // Verify that the remaining login have the most recent date.
+  loginTimeLastUsed = deduped[0].QueryInterface(Ci.nsILoginMetaInfo).timeLastUsed;
+  Assert.equal(loginTimeLastUsed, Date.UTC(2015, 11, 4, 0, 0, 0), "Most recent login was kept.");
+});