Return after callback to prevent calling subsequent callback (#141)

Author: urnotsam

src/eth-handlers/eth_getTransactionByBlockHashAndIndex.ts

@@ -73,6 +73,7 @@ export const buildGetTransactionByBlockHashAndIndex = ({
       callback(errorBusy)
       countFailedResponse(api_name, 'exception in collectorAPI.getBlock')
       logEventEmitter.emit('fn_end', ticket, { success: false }, performance.now())
+      return
     }
     const blockHash = (args as any)[0]
     const index = parseInt((args as any)[1], 16)
@@ -104,21 +105,21 @@ export const buildGetTransactionByBlockHashAndIndex = ({
           { nodeUrl, success: res.data.transactions.length ? true : false },
           performance.now()
         )
+        return
       } catch (error) {
         /* prettier-ignore */ if (verbose) console.log('Error: eth_getTransactionByBlockHashAndIndex', (error as AxiosError).message)
         callback(null, null)
         countFailedResponse(api_name, 'exception in axios.get')
         logEventEmitter.emit('fn_end', ticket, { success: false }, performance.now())
+        return
       }
     } else {
       console.log('queryFromValidator and/or queryFromExplorer turned off. Could not process request')
       callback(null, null)
       countFailedResponse(api_name, 'queryFromValidator and/or queryFromExplorer turned off')
       logEventEmitter.emit('fn_end', ticket, { success: true }, performance.now())
+      return
     }
-    callback(null, result)
-    countSuccessResponse(api_name, 'success', 'fallback')
-    logEventEmitter.emit('fn_end', ticket, { success: true }, performance.now())
   }
 
   return eth_getTransactionByBlockHashAndIndex

src/eth-handlers/eth_getTransactionByBlockNumberAndIndex.ts

@@ -72,7 +72,9 @@ export const buildGetTransactionByBlockNumberAndIndex = ({
       callback(errorBusy)
       countFailedResponse(api_name, 'exception in collectorAPI.getBlock')
       logEventEmitter.emit('fn_end', ticket, { success: false }, performance.now())
+      return
     }
+
     /* prettier-ignore */ if (firstLineLogs) { console.log('Running eth_getTransactionByBlockNumberAndIndex', args) }
     let blockNumber = (args as any)[0]
     const index = parseInt((args as any)[1], 16)
@@ -105,21 +107,21 @@ export const buildGetTransactionByBlockNumberAndIndex = ({
           { nodeUrl, success: res.data.transactions.length ? true : false },
           performance.now()
         )
+        return
       } catch (error) {
         /* prettier-ignore */ if (verbose) console.log('Error: eth_getTransactionByBlockNumberAndIndex', (error as AxiosError).message)
         callback(null, null)
         countFailedResponse(api_name, 'exception in axios.get')
         logEventEmitter.emit('fn_end', ticket, { success: false }, performance.now())
+        return
       }
     } else {
       console.log('queryFromExplorer turned off. Could not process request')
       callback(null, null)
       countFailedResponse(api_name, 'queryFromExplorer turned off')
       logEventEmitter.emit('fn_end', ticket, { success: true }, performance.now())
+      return
     }
-    callback(null, result)
-    countSuccessResponse(api_name, 'success', 'fallback')
-    logEventEmitter.emit('fn_end', ticket, { success: true }, performance.now())
   }
 
   return eth_getTransactionByBlockNumberAndIndex

test/unit/eth-handlers/eth_getTransactionByBlockHashAndIndex.test.ts

@@ -247,9 +247,7 @@ describe('eth_getTransactionByBlockHashAndIndex handler', () => {
       // The implementation calls callback twice:
       // First in the explorer path with null (no result)
       expect(mockCallback).toHaveBeenNthCalledWith(1, null, undefined)
-      // Then again at the end of the function with the original result variable (still undefined)
-      expect(mockCallback).toHaveBeenNthCalledWith(2, null, undefined)
-      expect(mockCallback).toHaveBeenCalledTimes(2)
+      expect(mockCallback).toHaveBeenCalledTimes(1)
     })
 
     it('should handle explorer unsuccessful response', async () => {
@@ -271,9 +269,7 @@ describe('eth_getTransactionByBlockHashAndIndex handler', () => {
       // The implementation calls callback twice:
       // First in the explorer path with null (unsuccessful response)
       expect(mockCallback).toHaveBeenNthCalledWith(1, null, null)
-      // Then again at the end of the function with the original result variable (undefined in the refactored test)
-      expect(mockCallback).toHaveBeenNthCalledWith(2, null, undefined)
-      expect(mockCallback).toHaveBeenCalledTimes(2)
+      expect(mockCallback).toHaveBeenCalledTimes(1)
     })
   })
 

test/unit/eth-handlers/eth_getTransactionByBlockNumberAndIndex.test.ts

@@ -312,9 +312,7 @@ describe('eth_getTransactionByBlockNumberAndIndex handler', () => {
       // The implementation calls callback twice:
       // First in the explorer path with null (no result)
       expect(mockCallback).toHaveBeenNthCalledWith(1, null, undefined)
-      // Then again at the end of the function with the original result variable (still undefined)
-      expect(mockCallback).toHaveBeenNthCalledWith(2, null, undefined)
-      expect(mockCallback).toHaveBeenCalledTimes(2)
+      expect(mockCallback).toHaveBeenCalledTimes(1)
     })
 
     it('should handle explorer unsuccessful response', async () => {
@@ -339,9 +337,7 @@ describe('eth_getTransactionByBlockNumberAndIndex handler', () => {
       // The implementation calls callback twice:
       // First in the explorer path with null (unsuccessful response)
       expect(mockCallback).toHaveBeenNthCalledWith(1, null, null)
-      // Then again at the end of the function with the original result variable (undefined in the refactored test)
-      expect(mockCallback).toHaveBeenNthCalledWith(2, null, undefined)
-      expect(mockCallback).toHaveBeenCalledTimes(2)
+      expect(mockCallback).toHaveBeenCalledTimes(1)
     })
 
     it('should handle "earliest" block tag correctly', async () => {