[BUG] [Client] [Java] [Vertx] Current context may return NPE when creating new WebClient

[ricardozanini]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

Hi!

While testing the generated client code for the petstore.yaml example, the ApiClient.java code is returning NPEs the first time it tries to create a WebClient reference. More specifically here: https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/resources/Java/libraries/vertx/ApiClient.mustache#L124-L132

Is there a reason to not use this.vertx.getOrCreateContext() instead? The vertx attribute is final. I can send a small PR to fix this, but I'd like to hear from the contributors first.

openapi-generator version

5.0.0

OpenAPI declaration file content or URL

Tested with petstore.yaml simple example.

Generation Details

Here's my plugin configuration:

<build>
    <plugins>
      <plugin>
        <groupId>org.openapitools</groupId>
        <artifactId>openapi-generator-maven-plugin</artifactId>
        <version>${version.openapi.generator}</version>
        <executions>
          <execution>
            <id>default</id>
            <goals>
              <goal>generate</goal>
            </goals>
            <configuration>
              <inputSpec>${project.basedir}/src/main/resources/petstore.yaml</inputSpec>
              <generatorName>java</generatorName>
              <library>vertx</library>
              <configOptions>
                <dateLibrary>java8</dateLibrary>
              </configOptions>
              <apiPackage>${project.groupId}.client</apiPackage>
              <modelPackage>${project.groupId}.client</modelPackage>
              <invokerPackage>${project.groupId}.client</invokerPackage>
              <generateApiTests>false</generateApiTests>
              <generateModelTests>false</generateModelTests>
              <generateModelDocumentation>false</generateModelDocumentation>
              <generateApiDocumentation>false</generateApiDocumentation>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

Steps to reproduce

1. Generate the Code
2. Run the tests with Junit5 and Vertx 3.9.5 (https://vertx.io/docs/3.9.5/vertx-junit5/java/)

Related issues/PRs

There's none

Suggest a fix

Replace Vertx.currentContext with this.vertx.getOrCreateContext()

By the way, I see that the server-side was upgraded to Vertx 4 (#7352). Don't we need to upgrade the client code as well? I can also send a PR for this purpose.

[wing328]

@ricardozanini thanks for reporting the issue. Please submit a PR to address these issues and we'll review accordingly. Let me know if you need help with the PR.

[ricardozanini]

@ricardozanini thanks for reporting the issue. Please submit a PR to address these issues and we'll review accordingly. Let me know if you need help with the PR.

@wing328 I've opened the PR (#8492), but it seems that we are lacking reviewers. Do you mind taking a look? Many thanks! 🙌

[wing328]

Thanks for the PR. Will try to review later today.

[wing328]

@ricardozanini do you mind sharing more on how you reproduce the issue? We do have some tests in https://github.com/OpenAPITools/openapi-generator/blob/master/samples/client/petstore/java/vertx/src/test/java/org/openapitools/client/api/PetApiTest.java#L55-L61 so would appreciate if you can add some tests in that test file to catch the issue moving forward.

[ricardozanini]

do you mind sharing more on how you reproduce the issue?

@wing328, the error only occurs on JUnit 5 + Vertx 3.9.x. This test case of yours will always work. In the PR, I added a verification code to ensure the Vertx context is never null. Instead of using the static class, we use the one provided by the constructor.

You would need to create a JUnit test like this one:
https://github.com/ricardozanini/openapi-codegen-poc/blob/main/src/test/java/com/github/zanini/openapi/codegen/PetStoreAPITest.java

Since our project here uses Junit 4, we won't catch the problem.

I don't think we need another unit test. What would be great is to upgrade to JUnit 5 and Vertx 4.x.

I can do it another time.

[wing328]

@ricardozanini thanks for the explanation. I've merged your fix.

Can you please file a PR to upgrade dependencies to JUnit 5 and Vertx 4.x when you've time?

[ricardozanini]

@wing328 of course, I'll do it. Should I open an issue first?

[wing328]

Up to you. You can also link the PR to the discussion here