Fix #8974 by supporting strings in configureLogging for SignalR JS client (#9252)

Author: analogrelay

src/SignalR/clients/ts/signalr/src/HubConnectionBuilder.ts

@@ -13,6 +13,31 @@ import { JsonHubProtocol } from "./JsonHubProtocol";
 import { NullLogger } from "./Loggers";
 import { Arg, ConsoleLogger } from "./Utils";
 
+// tslint:disable:object-literal-sort-keys
+const LogLevelNameMapping = {
+    trace: LogLevel.Trace,
+    debug: LogLevel.Debug,
+    info: LogLevel.Information,
+    information: LogLevel.Information,
+    warn: LogLevel.Warning,
+    warning: LogLevel.Warning,
+    error: LogLevel.Error,
+    critical: LogLevel.Critical,
+    none: LogLevel.None,
+};
+
+function parseLogLevel(name: string): LogLevel {
+    // Case-insensitive matching via lower-casing
+    // Yes, I know case-folding is a complicated problem in Unicode, but we only support
+    // the ASCII strings defined in LogLevelNameMapping anyway, so it's fine -anurse.
+    const mapping = LogLevelNameMapping[name.toLowerCase()];
+    if (typeof mapping !== "undefined") {
+        return mapping;
+    } else {
+        throw new Error(`Unknown log level: ${name}`);
+    }
+}
+
 /** A builder for configuring {@link @aspnet/signalr.HubConnection} instances. */
 export class HubConnectionBuilder {
     /** @internal */
@@ -44,15 +69,26 @@ export class HubConnectionBuilder {
 
     /** Configures custom logging for the {@link @aspnet/signalr.HubConnection}.
      *
-     * @param {LogLevel | ILogger} logging An object implementing the {@link @aspnet/signalr.ILogger} interface or {@link @aspnet/signalr.LogLevel}.
+     * @param {string} logLevel A string representing a LogLevel setting a minimum level of messages to log.
+     *    See {@link https://docs.microsoft.com/en-us/aspnet/core/signalr/configuration#configure-logging|the documentation for client logging configuration} for more details.
+     */
+    public configureLogging(logLevel: string): HubConnectionBuilder;
+
+    /** Configures custom logging for the {@link @aspnet/signalr.HubConnection}.
+     *
+     * @param {LogLevel | string | ILogger} logging A {@link @aspnet/signalr.LogLevel}, a string representing a LogLevel, or an object implementing the {@link @aspnet/signalr.ILogger} interface.
+     *    See {@link https://docs.microsoft.com/en-us/aspnet/core/signalr/configuration#configure-logging|the documentation for client logging configuration} for more details.
      * @returns The {@link @aspnet/signalr.HubConnectionBuilder} instance, for chaining.
      */
-    public configureLogging(logging: LogLevel | ILogger): HubConnectionBuilder;
-    public configureLogging(logging: LogLevel | ILogger): HubConnectionBuilder {
+    public configureLogging(logging: LogLevel | string | ILogger): HubConnectionBuilder;
+    public configureLogging(logging: LogLevel | string | ILogger): HubConnectionBuilder {
         Arg.isRequired(logging, "logging");
 
         if (isLogger(logging)) {
             this.logger = logging;
+        } else if (typeof logging === "string") {
+            const logLevel = parseLogLevel(logging);
+            this.logger = new ConsoleLogger(logLevel);
         } else {
             this.logger = new ConsoleLogger(logging);
         }
@@ -92,7 +128,7 @@ export class HubConnectionBuilder {
         // Flow-typing knows where it's at. Since HttpTransportType is a number and IHttpConnectionOptions is guaranteed
         // to be an object, we know (as does TypeScript) this comparison is all we need to figure out which overload was called.
         if (typeof transportTypeOrOptions === "object") {
-            this.httpConnectionOptions = {...this.httpConnectionOptions, ...transportTypeOrOptions};
+            this.httpConnectionOptions = { ...this.httpConnectionOptions, ...transportTypeOrOptions };
         } else {
             this.httpConnectionOptions = {
                 ...this.httpConnectionOptions,

src/SignalR/clients/ts/signalr/src/Utils.ts

@@ -147,26 +147,35 @@ export class SubjectSubscription<T> implements ISubscription<T> {
 export class ConsoleLogger implements ILogger {
     private readonly minimumLogLevel: LogLevel;
 
+    // Public for testing purposes.
+    public outputConsole: {
+        error(message: any): void,
+        warn(message: any): void,
+        info(message: any): void,
+        log(message: any): void,
+    };
+
     constructor(minimumLogLevel: LogLevel) {
         this.minimumLogLevel = minimumLogLevel;
+        this.outputConsole = console;
     }
 
     public log(logLevel: LogLevel, message: string): void {
         if (logLevel >= this.minimumLogLevel) {
             switch (logLevel) {
                 case LogLevel.Critical:
                 case LogLevel.Error:
-                    console.error(`[${new Date().toISOString()}] ${LogLevel[logLevel]}: ${message}`);
+                    this.outputConsole.error(`[${new Date().toISOString()}] ${LogLevel[logLevel]}: ${message}`);
                     break;
                 case LogLevel.Warning:
-                    console.warn(`[${new Date().toISOString()}] ${LogLevel[logLevel]}: ${message}`);
+                    this.outputConsole.warn(`[${new Date().toISOString()}] ${LogLevel[logLevel]}: ${message}`);
                     break;
                 case LogLevel.Information:
-                    console.info(`[${new Date().toISOString()}] ${LogLevel[logLevel]}: ${message}`);
+                    this.outputConsole.info(`[${new Date().toISOString()}] ${LogLevel[logLevel]}: ${message}`);
                     break;
                 default:
                     // console.debug only goes to attached debuggers in Node, so we use console.log for Trace and Debug
-                    console.log(`[${new Date().toISOString()}] ${LogLevel[logLevel]}: ${message}`);
+                    this.outputConsole.log(`[${new Date().toISOString()}] ${LogLevel[logLevel]}: ${message}`);
                     break;
             }
         }