Merge pull request #59 from tabkram/fix/trace-handler

fix: improve @trace execution to correctly auto bind the class context to the  handler

Author: tabkram

src/execution/execute.ts

@@ -62,18 +62,19 @@ export function execute<INPUT extends unknown[], OUTPUT, RESPONSE = OUTPUT, ERRO
       )
       .catch((error) => (errorCallback ? (errorCallback.bind(this) as typeof errorCallback)(error, true) : error));
   } else {
+    let result;
     try {
-      const result = blockFunction.bind(this)(...inputs, ...extraInputs);
-      if (result instanceof Promise) {
-        return result
-          .then((output: OUTPUT) =>
-            successCallback ? (successCallback.bind(this) as typeof successCallback)(output, true) : (output as unknown as RESPONSE)
-          )
-          .catch((error) => (errorCallback ? (errorCallback.bind(this) as typeof errorCallback)(error, true) : error));
-      }
-      return successCallback ? (successCallback.bind(this) as typeof successCallback)(result, false) : (result as unknown as RESPONSE);
+      result = blockFunction.bind(this)(...inputs, ...extraInputs);
     } catch (error) {
       return errorCallback ? (errorCallback.bind(this) as typeof errorCallback)(error, false) : error;
     }
+    if (result instanceof Promise) {
+      return result
+        .then((output: OUTPUT) =>
+          successCallback ? (successCallback.bind(this) as typeof successCallback)(output, true) : (output as unknown as RESPONSE)
+        )
+        .catch((error) => (errorCallback ? (errorCallback.bind(this) as typeof errorCallback)(error, true) : error));
+    }
+    return successCallback ? (successCallback.bind(this) as typeof successCallback)(result, false) : (result as unknown as RESPONSE);
   }
 }

src/trace/traceDecorator.spec.ts

@@ -22,6 +22,7 @@ describe('trace decorator', () => {
 
   describe('Tracing synchronous functions', () => {
     const traceHandlerMock = jest.fn();
+    const traceHandlerMockThrows = jest.fn();
 
     class SyncClass {
       greetingFrom = ['hello from class'];
@@ -35,11 +36,21 @@ describe('trace decorator', () => {
         this.greetingFrom.push('hello from method');
         return 'Hello World';
       }
+
+      @trace((...args) => {
+        traceHandlerMockThrows(...args);
+        throw new Error('hello but I throw!');
+      })
+      helloWorldHandlerThrows(): string {
+        this.greetingFrom.push('hello from method');
+        return 'Hello World';
+      }
     }
 
     it('should trace a synchronous function and verify context', () => {
       const instance = new SyncClass();
       expect(instance.helloWorld()).toBe('Hello World');
+      expect(traceHandlerMock).toHaveBeenCalledTimes(1);
       expect(traceHandlerMock).toHaveBeenCalledWith(
         expect.objectContaining({
           metadata: expect.objectContaining({
@@ -54,6 +65,25 @@ describe('trace decorator', () => {
         })
       );
     });
+
+    it('should trace a synchronous function and verify helloWorldHandlerThrows', () => {
+      const instance = new SyncClass();
+      expect(() => instance.helloWorldHandlerThrows()).toThrowError('hello but I throw!');
+      expect(traceHandlerMockThrows).toHaveBeenCalledTimes(1);
+      expect(traceHandlerMockThrows).toHaveBeenCalledWith(
+        expect.objectContaining({
+          metadata: expect.objectContaining({
+            class: 'SyncClass',
+            method: 'helloWorldHandlerThrows',
+            name: 'helloWorldHandlerThrows',
+            parameters: [],
+            isAsync: false,
+            isBound: false
+          }),
+          ...successfulExecutionTraceExpectation
+        })
+      );
+    });
   });
 
   describe('Asynchronous functions', () => {
@@ -142,8 +172,8 @@ describe('trace decorator', () => {
         url: string,
         traceContext: Record<string, unknown> = {}
       ): Promise<{
-        data: string;
-      }> {
+          data: string;
+        }> {
         return this.fetchDataFunction(url, traceContext);
       }