add monitorMethod decorator

Author: SimonLdj

example/run.ts

@@ -1,6 +1,6 @@
 import 'dotenv/config';
 
-import {setGlobalInstance, StatsdPlugin, monitored, Monitor, increment} from '../src';
+import {setGlobalInstance, StatsdPlugin, monitored, Monitor, increment, monitorMethod} from '../src';
 
 setGlobalInstance(
     new Monitor({
@@ -104,3 +104,17 @@ increment('metric1');
 // Increment with type restriction
 type Color = 'red' | 'orange' | 'green';
 increment<Color>('red');
+
+// monitor method using decorator
+class Person {
+    firstName: string = 'Jon';
+    lastName: string = 'Doe';
+
+    @monitorMethod('person', {logErrorAsInfo: true})
+    getFullName() {
+        return `${this.firstName} ${this.lastName}`;
+    }
+}
+const person = new Person();
+const name = person.getFullName();
+console.log(`person's name is ${name}`);

src/globalInstance.ts

@@ -1,4 +1,5 @@
 import Monitor from './Monitor';
+import {MonitoredOptions} from './types';
 
 let instance: Monitor | undefined;
 
@@ -15,10 +16,19 @@ export function getGlobalInstance(): Monitor {
 }
 
 export const monitored: Monitor['monitored'] = (...args) => getGlobalInstance().monitored(...args);
+
 /**
  * @deprecated since version 2.0
  */
 export const getStatsdClient: Monitor['getStatsdClient'] = (...args) => getGlobalInstance().getStatsdClient(...args);
 export const increment: Monitor['increment'] = (...args) => getGlobalInstance().increment(...args);
 export const gauge: Monitor['gauge'] = (...args) => getGlobalInstance().gauge(...args);
 export const timing: Monitor['timing'] = (...args) => getGlobalInstance().timing(...args);
+
+export const monitorMethod = <T>(prefix?: string, options: MonitoredOptions<T> = {}) => {
+    return function (_target: Object, propertyKey: string, descriptor: PropertyDescriptor) {
+        const originalMethod = descriptor.value;
+        const metricName = `${prefix}${prefix ? '.' : ''}${propertyKey}`;
+        descriptor.value = monitored(metricName, originalMethod, options);
+    };
+};

tsconfig.json

@@ -18,8 +18,9 @@
         "lib": ["dom", "es2017"],
         "skipLibCheck": true,
         "noImplicitAny": false,
-        "useUnknownInCatchVariables": false
+        "useUnknownInCatchVariables": false,
+        "experimentalDecorators": true
     },
-    "include": ["src/**/*", "types/*.d.ts"],
+    "include": ["src/**/*", "types/*.d.ts", "example/**/*"],
     "exclude": ["__tests__", "dist"]
 }