Question:
I’ve had an old AWS Lambda function, that was declared as synchronous (used Promises), the declaration looked like this:
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exports.getSong = (event, context, callback) => { } |
It worked as intended. Recently, I decided to re-write it using async/await and thus, tried declaring the getSong function asynchronously, like so:
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exports.getSong = async (event, context) => { } |
And while trying to execute, I get the following error in it’s entirety:
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{ "errorType": "Runtime.UserCodeSyntaxError", "errorMessage": "SyntaxError: Unexpected token '.'", "trace": [ "Runtime.UserCodeSyntaxError: SyntaxError: Unexpected token '.'", " at _loadUserApp (/var/runtime/UserFunction.js:98:13)", " at Object.module.exports.load (/var/runtime/UserFunction.js:140:17)", " at Object. " at Module._compile (internal/modules/cjs/loader.js:1133:30)", " at Object.Module._extensions..js (internal/modules/cjs/loader.js:1153:10)", " at Module.load (internal/modules/cjs/loader.js:977:32)", " at Function.Module._load (internal/modules/cjs/loader.js:877:14)", " at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:74:12)", " at internal/main/run_main_module.js:18:47" ] } |
It absolutely not clear what the issue is from this error message, but by googling for similar issues and narrowing everything down, I figured out that the problem is the function declaration.
I tried declaring the getSong function as synchronous, and then running another asynchronous function inside it, like so:
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var anotherAsyncFunction = async () => { } exports.getSong = (event, context, callback) => { anotherAsyncFunction() } |
But then, I get the same error. So clearly, it has something to do with the Asynchronous function declaration inside the Lambda. What might be the issue here? Thank you.
Answer:
I encounter a similar issue. for me it was res.Body?.toString('utf-8') which lambda could not understand what is Body?. i think in your case you should do the following :
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export const getSong = async (event, context) => { ...} |
also for whoever has the same problem, the best way to figure out the reason is to go to your lambda code page, it should show a red X on the line of code