PocketIC does not check for http outcalls reaching consensus

[ranile]

Problem

The following code runs perfectly on local network dfx start but fails on mainnet:

const JWK_URL: &str =
    "https://www.googleapis.com/service_accounts/v1/jwk/[email protected]";

pub async fn fetch_public_keys() -> Result<JwkKeys, FetchPublicKeysError> {
    let response =
        ic_cdk::management_canister::http_request(&ic_cdk::management_canister::HttpRequestArgs {
            url: JWK_URL.to_string(),
            max_response_bytes: None,
            method: ic_cdk::management_canister::HttpMethod::GET,
            headers: vec![],
            body: None,
            transform: None,
        })
        .await
        .map_err(FetchPublicKeysError::CouldntFetchPublicKeys)?;
// ...
}

The error: No consensus could be reached. Replicas had different responses.

I'm almost certain that the reason for this error is that HTTP response is different for each call to this URL (max-age header value changes). There's no way for such errors to be caught in development

Potential solution

PocketIC should try to make more than one HTTP call and compare response results, to better simulate the production environment. Just two calls would've caught the error for the aforementioned URL