Convert context.log to be more similar to Node.js console.log

Author: ejizba

src/InvocationContext.ts

@@ -2,7 +2,7 @@
 // Licensed under the MIT License.
 
 import * as types from '@azure/functions';
-import { ContextBindings, Logger, RetryContext, TraceContext, TriggerMetadata } from '@azure/functions';
+import { ContextBindings, RetryContext, TraceContext, TriggerMetadata } from '@azure/functions';
 import { RpcInvocationRequest, RpcLog, RpcParameterBinding } from '@azure/functions-core';
 import { convertKeysToCamelCase } from './converters/convertKeysToCamelCase';
 import { fromRpcRetryContext, fromRpcTraceContext, fromTypedData } from './converters/RpcConverters';
@@ -58,9 +58,9 @@ class InvocationContext implements types.InvocationContext {
     triggerMetadata: TriggerMetadata;
     traceContext?: TraceContext;
     retryContext?: RetryContext;
-    log: Logger;
     req?: Request;
     res?: Response;
+    #userLogCallback: UserLogCallback;
 
     constructor(info: FunctionInfo, request: RpcInvocationRequest, userLogCallback: UserLogCallback) {
         this.invocationId = <string>request.invocationId;
@@ -72,16 +72,33 @@ class InvocationContext implements types.InvocationContext {
         if (request.traceContext) {
             this.traceContext = fromRpcTraceContext(request.traceContext);
         }
+        this.#userLogCallback = userLogCallback;
 
         this.bindings = {};
+    }
+
+    log(...args: any[]): void {
+        this.#userLogCallback(RpcLog.Level.Information, ...args);
+    }
+
+    trace(...args: any[]): void {
+        this.#userLogCallback(RpcLog.Level.Trace, ...args);
+    }
+
+    debug(...args: any[]): void {
+        this.#userLogCallback(RpcLog.Level.Debug, ...args);
+    }
+
+    info(...args: any[]): void {
+        this.#userLogCallback(RpcLog.Level.Information, ...args);
+    }
+
+    warn(...args: any[]): void {
+        this.#userLogCallback(RpcLog.Level.Warning, ...args);
+    }
 
-        // Log message that is tied to function invocation
-        this.log = Object.assign((...args: any[]) => userLogCallback(RpcLog.Level.Information, ...args), {
-            error: (...args: any[]) => userLogCallback(RpcLog.Level.Error, ...args),
-            warn: (...args: any[]) => userLogCallback(RpcLog.Level.Warning, ...args),
-            info: (...args: any[]) => userLogCallback(RpcLog.Level.Information, ...args),
-            verbose: (...args: any[]) => userLogCallback(RpcLog.Level.Trace, ...args),
-        });
+    error(...args: any[]): void {
+        this.#userLogCallback(RpcLog.Level.Error, ...args);
     }
 }
 

types/index.d.ts

@@ -69,10 +69,41 @@ declare module '@azure/functions' {
         retryContext?: RetryContext;
 
         /**
-         * Allows you to write streaming function logs. Calling directly allows you to write streaming function logs
-         * at the default trace level.
+         * The recommended way to log data during invocation.
+         * Similar to Node.js's `console.log`, but has integration with Azure features like application insights
+         * Uses the 'information' log level
          */
-        log: Logger;
+        log(...args: any[]): void;
+
+        /**
+         * The recommended way to log trace data (level 0) during invocation.
+         * Similar to Node.js's `console.trace`, but has integration with Azure features like application insights
+         */
+        trace(...args: any[]): void;
+
+        /**
+         * The recommended way to log debug data (level 1) during invocation.
+         * Similar to Node.js's `console.debug`, but has integration with Azure features like application insights
+         */
+        debug(...args: any[]): void;
+
+        /**
+         * The recommended way to log information data (level 2) during invocation.
+         * Similar to Node.js's `console.info`, but has integration with Azure features like application insights
+         */
+        info(...args: any[]): void;
+
+        /**
+         * The recommended way to log warning data (level 3) during invocation.
+         * Similar to Node.js's `console.warn`, but has integration with Azure features like application insights
+         */
+        warn(...args: any[]): void;
+
+        /**
+         * The recommended way to log error data (level 4) during invocation.
+         * Similar to Node.js's `console.error`, but has integration with Azure features like application insights
+         */
+        error(...args: any[]): void;
 
         /**
          * HTTP request object. Provided to your function when using HTTP Bindings.
@@ -430,31 +461,7 @@ declare module '@azure/functions' {
          */
         direction: 'in' | 'out' | 'inout' | undefined;
     }
-    /**
-     * Allows you to write streaming function logs.
-     */
-    export interface Logger {
-        /**
-         * Writes streaming function logs at the default trace level.
-         */
-        (...args: any[]): void;
-        /**
-         * Writes to error level logging or lower.
-         */
-        error(...args: any[]): void;
-        /**
-         * Writes to warning level logging or lower.
-         */
-        warn(...args: any[]): void;
-        /**
-         * Writes to info level logging or lower.
-         */
-        info(...args: any[]): void;
-        /**
-         * Writes to verbose level logging.
-         */
-        verbose(...args: any[]): void;
-    }
+
     /**
      * Timer schedule information. Provided to your function when using a timer binding.
      */

types/index.test.ts

@@ -47,9 +47,9 @@ export const timerTrigger: AzureFunction = async function (context: InvocationCo
 
 const runServiceBus: AzureFunction = async function (context: InvocationContext, myQueueItem: string) {
     context.log('Node.js ServiceBus queue trigger function processed message', myQueueItem);
-    context.log.verbose('EnqueuedTimeUtc =', context.triggerMetadata.enqueuedTimeUtc);
-    context.log.verbose('DeliveryCount =', context.triggerMetadata.deliveryCount);
-    context.log.verbose('MessageId =', context.triggerMetadata.messageId);
+    context.trace('EnqueuedTimeUtc =', context.triggerMetadata.enqueuedTimeUtc);
+    context.trace('DeliveryCount =', context.triggerMetadata.deliveryCount);
+    context.trace('MessageId =', context.triggerMetadata.messageId);
 };
 
 // Assumes output binding is named '$return'