feat: handle tx metadata generation errors (#65)

src/handlers/transactionMetadata.ts

@@ -1,10 +1,18 @@
 import { Response, Request } from 'express'
 import { Chain, getChains } from '../utils/chains'
-import { renderChainNotFoundError, renderGetMetadataFirstError, renderInternalError, renderMissingTxBlobError } from '../utils/errors'
+import {
+  renderChainNotFoundError,
+  renderGetMetadataFirstError,
+  renderInternalError,
+  renderMissingTxBlobError,
+  renderShortenerMetadataError
+} from '../utils/errors'
 import { cacheMetadata } from '../utils/metadata'
 import { getShortMetadataFromTxBlob } from '../../rust'
 import { TxToSign } from '../utils/types'
 
+const validHex = new RegExp(/^[a-fA-F0-9]+$/)
+
 export const transactionMetadata = async (req: Request, res: Response) => {
   const chains = getChains()
 
@@ -45,7 +53,13 @@ export const transactionMetadata = async (req: Request, res: Response) => {
       txBlob = txBlob.substring(2)
     }
 
-    const txMetadata = Buffer.from(getShortMetadataFromTxBlob({ txBlob, metadata: metadataHex, props }), 'hex')
+    const result = getShortMetadataFromTxBlob({ txBlob, metadata: metadataHex, props })
+
+    if(!validHex.test(result)){
+      renderShortenerMetadataError(res, result)
+      return
+    }
+    const txMetadata = Buffer.from(result, 'hex')
     res.status(200).send({ txMetadata: '0x' + txMetadata.toString('hex') })
   } catch (e) {
     renderInternalError(res, e)

src/utils/errors.ts

@@ -9,6 +9,10 @@ export const renderError = (res: Response, httpCode: number, e: unknown) => {
   res.status(httpCode).json({ errorMessage })
 }
 
+export const renderShortenerMetadataError = (res: Response, e: string) => {
+  renderError(res, 500, new Error("failed to generate shortened metadata: [" + e + "]" ))
+}
+
 export const renderInternalError = (res: Response, e: unknown) => {
   const errorMessage = e instanceof ChainError ? e.message : defaultInternalErrorMsg
   renderError(res, 500, new Error(errorMessage))

tests/common.test.ts

@@ -1,5 +1,5 @@
 import { createAndServe } from '../src/server'
-import axios from 'axios'
+import axios, {Axios, AxiosError, isAxiosError} from 'axios'
 import { describe } from 'node:test'
 import http from 'http'
 
@@ -56,6 +56,24 @@ describe('basic api', () => {
     )
   })
 
+  test('fail to get tx metadata', async () => {
+    try {
+      const resp = await axios.post('http://127.0.0.1:3001/transaction/metadata', {
+        txBlob:
+          '11001c0c591bd5a5f69ae815f6aae85433bf5ef7e703cbb9c8b64bc69731252d4c0121710f001a0000006408de7737c59c238890533af25896a2c20608d8b380bb01029acb392781063eacb0ce6e825b73b46536726994c63f4684fd8a72976e07f551de5954f0df5cb501b6648e3f302d557ff1ee5e6d2462f2c668b1c4ac92db6a05c6ab857372c10a13',
+        chain: {id: 'roc'},
+      })
+    }catch(e:any){
+        expect(isAxiosError(e)).toBe(true)
+        expect(!!e.response).toBe(true)
+        expect(!!e.response.data).toBe(true)
+        if(e.response && e.response.data){
+          expect(e.response.status).toBe(500)
+          expect(e.response.data.errorMessage).toBe("failed to generate shortened metadata: [Failed to decode call: Could not find variant with index 17]")
+        }
+    }
+  })
+
   test('flush chain metadata', async () => {
     const resp = await axios.post('http://127.0.0.1:3001/node/metadata/flush', { id: 'roc' })
     expect(resp.status).toBe(200)