Bug 1599567 - Add telemetry for when logins store is unusable because of missing or corrupt logins.json file. r=MattN

Differential Revision: https://phabricator.services.mozilla.com/D78477

browser/components/aboutlogins/tests/browser/head.js

@@ -101,6 +101,12 @@ add_task(async function setup_head() {
       // Ignore warnings and non-errors.
       return;
     }
+
+    if (msg.errorMessage.includes('Unknown event: ["jsonfile", "load"')) {
+      // Ignore telemetry errors from JSONFile.jsm.
+      return;
+    }
+
     if (
       msg.errorMessage == "Refreshing device list failed." ||
       msg.errorMessage == "Skipping device list refresh; not signed in"

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

@@ -0,0 +1,67 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+ChromeUtils.defineModuleGetter(
+  this,
+  "LoginStore",
+  "resource://gre/modules/LoginStore.jsm"
+);
+const { TelemetryTestUtils } = ChromeUtils.import(
+  "resource://testing-common/TelemetryTestUtils.jsm"
+);
+
+/**
+ * Tests collecting telemetry when login store is missing.
+ */
+add_task(async function test_login_store_missing_telemetry() {
+  // Clear events recorded in the jsonfile category during startup.
+  Services.telemetry.clearEvents();
+
+  // Check that logins.json does not exist.
+  let loginsStorePath = OS.Path.join(
+    OS.Constants.Path.profileDir,
+    "logins.json"
+  );
+  Assert.equal(false, await OS.File.exists(loginsStorePath));
+
+  // Create a LoginStore.jsm object and try to load logins.json.
+  let store = new LoginStore(loginsStorePath);
+  await store.load();
+
+  TelemetryTestUtils.assertEvents(
+    [["jsonfile", "load", "logins"]],
+    {},
+    { clear: true }
+  );
+});
+
+/**
+ * Tests collecting telemetry when the login store is corrupt.
+ */
+add_task(async function test_login_store_corrupt_telemetry() {
+  let loginsStorePath = OS.Path.join(
+    OS.Constants.Path.profileDir,
+    "logins.json"
+  );
+  let store = new LoginStore(loginsStorePath);
+
+  let string = '{"logins":[{"hostname":"http://www.example.com","id":1,';
+  await OS.File.writeAtomic(store.path, new TextEncoder().encode(string));
+  await store.load();
+
+  // A .corrupt file should have been created.
+  Assert.ok(await OS.File.exists(store.path + ".corrupt"));
+
+  TelemetryTestUtils.assertEvents(
+    [
+      ["jsonfile", "load", "logins", ""],
+      ["jsonfile", "load", "logins", "invalid_json"],
+    ],
+    {},
+    { clear: true }
+  );
+
+  // Clean up.
+  await OS.File.remove(store.path + ".corrupt");
+  await OS.File.remove(store.path);
+});

toolkit/components/passwordmgr/test/unit/xpcshell.ini

@@ -8,6 +8,8 @@ support-files = data/**
 skip-if = os == "android"
 [test_module_LoginStore.js]
 skip-if = os == "android"
+[test_module_LoginStoreTelemetry.js]
+skip-if = os == "android"
 
 # The following tests apply to any storage back-end that supports add/modify/remove.
 [test_context_menu.js]

toolkit/components/telemetry/Events.yaml

@@ -780,6 +780,18 @@ pwmgr:
       - "firefox"
     record_in_processes: [content, main]
 
+jsonfile:
+  load:
+    description: >
+      Records when JSONFile.jsm consumers are trying to access a missing or corrupt json file.
+      For example, Login Store trying to access logins.json when it has gone missing or corrupt.
+    objects: ["logins", "autofillprofiles"]
+    bug_numbers: [1599567]
+    expiry_version: never
+    products: ["firefox"]
+    record_in_processes: [main] 
+    notification_emails: ["prathiksha@mozilla.com", "passwords-dev@mozilla.org"]
+
 fxa:
   connect:
     objects: ["account"]

toolkit/modules/JSONFile.jsm

@@ -72,6 +72,12 @@ const FileInputStream = Components.Constructor(
   "init"
 );
 
+ChromeUtils.defineModuleGetter(
+  this,
+  "Services",
+  "resource://gre/modules/Services.jsm"
+);
+
 /**
  * Delay between a change to the data and the related save operation.
  */
@@ -130,6 +136,8 @@ function JSONFile(config) {
     "JSON store: writing data",
     this._finalizeInternalBound
   );
+
+  Services.telemetry.setEventRecordingEnabled("jsonfile", true);
 }
 
 JSONFile.prototype = {
@@ -213,6 +221,16 @@ JSONFile.prototype = {
       // just start with new data.  Other errors may indicate that the file is
       // corrupt, thus we move it to a backup location before allowing it to
       // be overwritten by an empty file.
+      let cleansedBasename = OS.Path.basename(this.path)
+        .replace(/\.json$/, "")
+        .replaceAll(/[^a-zA-Z0-9_.]/g, "");
+      let errorNo = ex.winLastError || ex.unixErrno;
+      Services.telemetry.recordEvent(
+        "jsonfile",
+        "load",
+        cleansedBasename,
+        errorNo ? errorNo.toString() : ""
+      );
       if (!(ex instanceof OS.File.Error && ex.becauseNoSuchFile)) {
         Cu.reportError(ex);
 
@@ -223,6 +241,12 @@ JSONFile.prototype = {
           });
           await openInfo.file.close();
           await OS.File.move(this.path, openInfo.path);
+          Services.telemetry.recordEvent(
+            "jsonfile",
+            "load",
+            cleansedBasename,
+            "invalid_json"
+          );
         } catch (e2) {
           Cu.reportError(e2);
         }