Bug 1874957 - Add a shouldLog function to ConsoleInstance. r=dom-core,webidl,saschanaz,peterv

Differential Revision: https://phabricator.services.mozilla.com/D199796

Author: Standard8

dom/console/ConsoleInstance.cpp

@@ -5,6 +5,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "mozilla/dom/ConsoleInstance.h"
+#include "Console.h"
 #include "mozilla/dom/ConsoleBinding.h"
 #include "mozilla/Preferences.h"
 #include "ConsoleCommon.h"
@@ -243,6 +244,11 @@ void ConsoleInstance::Clear(JSContext* aCx) {
   console->MethodInternal(aCx, Console::MethodClear, u"clear"_ns, data);
 }
 
+bool ConsoleInstance::ShouldLog(ConsoleLogLevel aLevel) {
+  return mConsole->mCurrentLogLevel <=
+         mConsole->WebIDLLogLevelToInteger(aLevel);
+}
+
 void ConsoleInstance::ReportForServiceWorkerScope(const nsAString& aScope,
                                                   const nsAString& aMessage,
                                                   const nsAString& aFilename,

dom/console/ConsoleInstance.h

@@ -96,6 +96,8 @@ class ConsoleInstance final : public nsISupports, public nsWrapperCache {
   MOZ_CAN_RUN_SCRIPT
   void Clear(JSContext* aCx);
 
+  bool ShouldLog(ConsoleLogLevel aLevel);
+
   // For testing only.
   void ReportForServiceWorkerScope(const nsAString& aScope,
                                    const nsAString& aMessage,

dom/console/tests/xpcshell/test_console_shouldLog.js

@@ -0,0 +1,35 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+add_task(async function test_shouldLog_maxLogLevel() {
+  let ci = console.createInstance({ maxLogLevel: "Warn" });
+
+  Assert.ok(
+    ci.shouldLog("Error"),
+    "Should return true for logging a higher level"
+  );
+  Assert.ok(
+    ci.shouldLog("Warn"),
+    "Should return true for logging the same level"
+  );
+  Assert.ok(
+    !ci.shouldLog("Debug"),
+    "Should return false for logging a lower level;"
+  );
+});
+
+add_task(async function test_shouldLog_maxLogLevelPref() {
+  Services.prefs.setStringPref("test.log", "Warn");
+  let ci = console.createInstance({ maxLogLevelPref: "test.log" });
+
+  Assert.ok(
+    !ci.shouldLog("Debug"),
+    "Should return false for logging a lower level;"
+  );
+
+  Services.prefs.setStringPref("test.log", "Debug");
+  Assert.ok(
+    ci.shouldLog("Debug"),
+    "Should return true for logging a lower level after pref update"
+  );
+});

dom/console/tests/xpcshell/xpcshell.toml

@@ -4,6 +4,8 @@ support-files = ""
 
 ["test_basic.js"]
 
+["test_console_shouldLog.js"]
+
 ["test_failing_console_listener.js"]
 
 ["test_formatting.js"]

dom/webidl/Console.webidl

@@ -198,6 +198,10 @@ interface ConsoleInstance {
 
   undefined profile(any... data);
   undefined profileEnd(any... data);
+
+  // Returns true if the given level would log a message. Used for avoiding
+  // long/significant processing when logging messages.
+  boolean shouldLog(ConsoleLogLevel level);
 };
 
 callback ConsoleInstanceDumpCallback = undefined (DOMString message);