(fix): Fix Typescript Timeouts when Lambda handler returns undefined#661
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(fix): Fix Typescript Timeouts when Lambda handler returns undefined#661
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| promise = Promise.race([callbackProm, asyncProm]); | ||
| } else if (asyncProm === undefined && handler.length < 3) { | ||
| // Handler returned undefined and doesn't take a callback parameter, resolve immediately | ||
| promise = Promise.resolve(undefined); |
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Great great find! We definitely need to get some tests in place for this.
Specifically, we need a test that would fail before this change, pass without it. Ideally it would also pass before the update to dogstatsd. Meaning it would have helped us catch this bug before releasing.
duncanista
approved these changes
Jun 12, 2025
purple4reina
approved these changes
Jun 12, 2025
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What does this PR do?
Originally, when Lambdas return
undefined(this also happens when thereturnstatement is missing), thepromisifiedHandlernever resolved.I'm not exactly sure how, but this bug in combination with my changes in #648 caused timeouts in Typescript apps. Timeouts did not occur before #648.
The fix here is to resolve
promisifiedHandlereven when the handler returns undefined.I'm not exactly sure why this only affects TS but not JS apps.
Motivation
Typescript Lambdas timing out when returning undefined
Testing Guidelines
Manually - no more timeouts
Added unit test -- fails without this change, passes with the change
Additional Notes
Types of Changes
Check all that apply