LibJS+WebContent+js: Reimplement console.log() and friends to spec

This implements the Logger and Printer abstract operations defined in
the console spec, and stubs out the Formatter AO. These are then used
for the "output a categorized log message" functions.

Userland/Libraries/LibJS/Console.cpp

@@ -1,6 +1,7 @@
 /*
  * Copyright (c) 2020, Emanuele Torre <torreemanuele6@gmail.com>
  * Copyright (c) 2020-2021, Linus Groh <linusg@serenityos.org>
+ * Copyright (c) 2021, Sam Atkins <atkinssj@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -20,53 +21,58 @@ VM& Console::vm()
     return m_global_object.vm();
 }
 
-Value Console::debug()
+// 1.1.3. debug(...data), https://console.spec.whatwg.org/#debug
+ThrowCompletionOr<Value> Console::debug()
 {
-#ifdef __serenity__
-    dbgln("\033[32;1m(js debug)\033[0m {}", vm().join_arguments());
-#endif
-    if (m_client)
-        return m_client->debug();
+    // 1. Perform Logger("debug", data).
+    if (m_client) {
+        auto data = vm_arguments();
+        return m_client->logger(LogLevel::Debug, data);
+    }
     return js_undefined();
 }
 
-Value Console::error()
+// 1.1.4. error(...data), https://console.spec.whatwg.org/#error
+ThrowCompletionOr<Value> Console::error()
 {
-#ifdef __serenity__
-    dbgln("\033[32;1m(js error)\033[0m {}", vm().join_arguments());
-#endif
-    if (m_client)
-        return m_client->error();
+    // 1. Perform Logger("error", data).
+    if (m_client) {
+        auto data = vm_arguments();
+        return m_client->logger(LogLevel::Error, data);
+    }
     return js_undefined();
 }
 
-Value Console::info()
+// 1.1.5. info(...data), https://console.spec.whatwg.org/#info
+ThrowCompletionOr<Value> Console::info()
 {
-#ifdef __serenity__
-    dbgln("\033[32;1m(js info)\033[0m {}", vm().join_arguments());
-#endif
-    if (m_client)
-        return m_client->info();
+    // 1. Perform Logger("info", data).
+    if (m_client) {
+        auto data = vm_arguments();
+        return m_client->logger(LogLevel::Info, data);
+    }
     return js_undefined();
 }
 
-Value Console::log()
+// 1.1.6. log(...data), https://console.spec.whatwg.org/#log
+ThrowCompletionOr<Value> Console::log()
 {
-#ifdef __serenity__
-    dbgln("\033[32;1m(js log)\033[0m {}", vm().join_arguments());
-#endif
-    if (m_client)
-        return m_client->log();
+    // 1. Perform Logger("log", data).
+    if (m_client) {
+        auto data = vm_arguments();
+        return m_client->logger(LogLevel::Log, data);
+    }
     return js_undefined();
 }
 
-Value Console::warn()
+// 1.1.9. warn(...data), https://console.spec.whatwg.org/#warn
+ThrowCompletionOr<Value> Console::warn()
 {
-#ifdef __serenity__
-    dbgln("\033[32;1m(js warn)\033[0m {}", vm().join_arguments());
-#endif
-    if (m_client)
-        return m_client->warn();
+    // 1. Perform Logger("warn", data).
+    if (m_client) {
+        auto data = vm_arguments();
+        return m_client->logger(LogLevel::Warn, data);
+    }
     return js_undefined();
 }
 
@@ -127,6 +133,42 @@ bool Console::counter_reset(String label)
     return true;
 }
 
+Vector<Value> Console::vm_arguments()
+{
+    Vector<Value> arguments;
+    arguments.ensure_capacity(vm().argument_count());
+    for (size_t i = 0; i < vm().argument_count(); ++i) {
+        arguments.append(vm().argument(i));
+    }
+    return arguments;
+}
+
+void Console::output_debug_message([[maybe_unused]] LogLevel log_level, [[maybe_unused]] String output) const
+{
+#ifdef __serenity__
+    switch (log_level) {
+    case JS::Console::LogLevel::Debug:
+        dbgln("\033[32;1m(js debug)\033[0m {}", output);
+        break;
+    case JS::Console::LogLevel::Error:
+        dbgln("\033[32;1m(js error)\033[0m {}", output);
+        break;
+    case JS::Console::LogLevel::Info:
+        dbgln("\033[32;1m(js info)\033[0m {}", output);
+        break;
+    case JS::Console::LogLevel::Log:
+        dbgln("\033[32;1m(js log)\033[0m {}", output);
+        break;
+    case JS::Console::LogLevel::Warn:
+        dbgln("\033[32;1m(js warn)\033[0m {}", output);
+        break;
+    default:
+        dbgln("\033[32;1m(js)\033[0m {}", output);
+        break;
+    }
+#endif
+}
+
 VM& ConsoleClient::vm()
 {
     return global_object().vm();
@@ -142,4 +184,45 @@ Vector<String> ConsoleClient::get_trace() const
     return trace;
 }
 
+// 2.1. Logger(logLevel, args), https://console.spec.whatwg.org/#logger
+ThrowCompletionOr<Value> ConsoleClient::logger(Console::LogLevel log_level, Vector<Value>& args)
+{
+    auto& global_object = this->global_object();
+
+    // 1. If args is empty, return.
+    if (args.is_empty())
+        return js_undefined();
+
+    // 2. Let first be args[0].
+    auto first = args[0];
+
+    // 3. Let rest be all elements following first in args.
+    size_t rest_size = args.size() - 1;
+
+    // 4. If rest is empty, perform Printer(logLevel, « first ») and return.
+    if (rest_size == 0) {
+        auto first_as_vector = Vector { first };
+        return printer(log_level, first_as_vector);
+    }
+
+    // 5. If first does not contain any format specifiers, perform Printer(logLevel, args).
+    if (!TRY(first.to_string(global_object)).contains('%')) {
+        TRY(printer(log_level, args));
+    } else {
+        // 6. Otherwise, perform Printer(logLevel, Formatter(args)).
+        auto formatted = TRY(formatter(args));
+        TRY(printer(log_level, formatted));
+    }
+
+    // 7. Return undefined.
+    return js_undefined();
+}
+
+// 2.2. Formatter(args), https://console.spec.whatwg.org/#formatter
+ThrowCompletionOr<Vector<Value>> ConsoleClient::formatter(Vector<Value>& args)
+{
+    // TODO: Actually implement formatting
+    return args;
+}
+
 }