Request CompletableFuture will never complete if an exception occurs

[RodionKorneev]

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Pre-Checklist

I made sure...

• I read the README.md
• I looked over the examples and wiki
• my issue hasn't been asked or solved before

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Describe the bug

CompletableFuture returned from IGClient.sendRequest(IGRequest<T> req) will never complete if an IOException occurs while processing the response body in ResponseBody.string(). Actually thrown exception does not affect CompletableFuture state and .get() or .join() call will await endlessly.

public <T extends IGResponse> CompletableFuture<T> sendRequest(@NonNull IGRequest<T> req) {
        CompletableFuture<Pair<Response, String>> responseFuture = new CompletableFuture<>();
        log.info("Sending request : {}", req.formUrl(this).toString());
        this.httpClient.newCall(req.formRequest(this)).enqueue(new Callback() {

            @Override
            public void onFailure(Call call, IOException exception) {
                responseFuture.completeExceptionally(exception);
            }

            @Override
            public void onResponse(Call call, Response res) throws IOException {
                log.info("Response for {} : {}", call.request().url().toString(), res.code());
                try (ResponseBody body = res.body()) {
                    responseFuture.complete(new Pair<>(res, body.string())); //<---- HERE
                }
            }

        });

        return responseFuture
                .thenApply(res -> {
                    setFromResponseHeaders(res.getFirst());
                    log.info("Response for {} with body (truncated) : {}",
                            res.getFirst().request().url(),
                            IGUtils.truncate(res.getSecond()));

                    return req.parseResponse(res);
                })
                .exceptionally((tr) -> {
                    return this.exceptionallyHandler.handle(tr, req.getResponseType());
                });
    }

How to reproduce

1. Specify steps to reproduce
   You could mock Response parameter and throw IOException on string() call.

Expected behavior

CompletableFuture.get() completes with exception response

Actual behavior

CompletableFuture.get() endlessly await