SyntaxError: Unexpected end of JSON input

[Rykuno]

Looks like #1280 might fix this when merged.

Description
With the update to 0.7.1 from 0.6.0, errors began to throw with SyntaxError: Unexpected end of JSON input when a record from the API returned null/undefined.

A brief description of the bug. Provide either a screenshot or the full error message

web:dev: SyntaxError: Unexpected end of JSON input
web:dev:     at JSON.parse (<anonymous>)

Reproduction
How can this be reproduced / when did the error occur? Does the issue occur in a specific browser, or all browsers?

Expected result
Expect null/undefined rather than failing to parse json

(in case it’s not obvious)

Checklist

• I’m willing to open a PR (see CONTRIBUTING.md)

[drwpow]

#1280 is unrelated and is on the typegen side; that won’t affect a runtime error like what you’re seeing.

So I’m assuming that your API does NOT return a 204 No content status, but instead, returns a 200 where the top-level response may be null. In that case, I’m not sure if we handle that. I guess this is a bug? But this is a curious API choice to return 200 with a null or undefined response at the root level. But technically not invalid.

[drwpow]

It should also be noted that we respect the Content-Length header, so if your API sent "Content-Length": "0" then we wouldn’t try and parse JSON in that instance, either.

[Rykuno]

We have this issue in two areas w/ the new version. The issue is this is happening for responses from two different very popular public API's; so we have no control over the implementation :(

[tuler]

I have a 202 response with Content-Type: text/plain and Content-Length: 27, which is a message.
And I'm getting a JSON parse error as well.

[KadoBOT]

got the same error:

Error: 26 |         // parse response (falling back to .text() when necessary)
27 |         if (response.ok) {
28 |             let data = response.body;
29 |             if (parseAs !== "stream") {
30 |                 const cloned = response.clone();
31 |                 data = typeof cloned[parseAs] === "function" ? await cloned[parseAs]() : await cloned.text();
                                                                         ^
SyntaxError: Unexpected end of JSON input

[StagnantIce]

Get the same error on last version for PATCH method with empty body

So if I send body: {} its works fine, but i have red line under because generated API not expected. (Response return 204)
If I remove body: {} its display me Unexpected end of JSON input (Response return 400)

[StagnantIce]

Another way to fix it add

@ApiBody({ schema: {} })

and send body: {}. But I m not sure that its correct way.

[yethee]

I faced with this issue when API server returns a response with status 202 and there is neither a body nor content-length header. As a workaround, I override the parse strategy (parseAs: 'stream') for a specific method to avoid the issue.

[brandonp-ais]

Hi, I am also experiencing this issue with a response status 202.

It should also be noted that we respect the Content-Length header, so if your API sent "Content-Length": "0" then we wouldn’t try and parse JSON in that instance, either.

We looked at this as a solution to the problem, but unfortunately it will not work as our backend API is incapable of doing this without significant memory increases.

https://github.com/spring-projects/spring-framework/wiki/Upgrading-to-Spring-Framework-6.x#web-applications

To reduce memory usage in RestClient and RestTemplate, most ClientHttpRequestFactory
implementations no longer buffer request bodies before sending them to the server. As a result, for certain content types such as JSON, the contents size is no longer known, and a Content-Length header is no longer set.

So this means that adding the header is effectively removed by SpringBoot.

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[github-actions]

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