[R] fix error handling in the R client

[mattpollock]

@Ramanth, @saigiridhar21, @wing328

This PR ensures that a client API provides the status code when generating a new ApiResponse for errors. Previously this was not done, with the result that a confusing R error was thrown while trying to handle the REST error. This obfuscated the REST errors, making them difficult to diagnose.

PR checklist

• Read the contribution guidelines.
• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• Run the following to build the project and update samples:

  ./mvnw clean package || exit
  ./bin/generate-samples.sh ./bin/configs/*.yaml || exit
  ./bin/utils/export_docs_generators.sh || exit
  

  (For Windows users, please run the script in WSL)
  Commit all changed files.
  This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master.
  These must match the expectations made by your contribution.
  You may regenerate an individual generator by passing the relevant config(s) as an argument to the script, for example ./bin/generate-samples.sh bin/configs/java*.
  IMPORTANT: Do NOT purge/delete any folders/files (e.g. tests) when regenerating the samples as manually written tests may be removed.
• File the PR against the correct branch: master (upcoming 7.x.0 minor release - breaking changes with fallbacks), 8.0.x (breaking changes without fallbacks)
• If your PR solves a reported issue, reference it using GitHub's linking syntax (e.g., having "fixes #123" present in the PR description)
• If your PR is targeting a particular programming language, @mention the technical committee members, so they are more likely to review the pull request.

---

Summary by cubic

Fixes R client error handling by always including the HTTP status code in ApiResponse and improving server error messages. This prevents secondary R errors and makes REST failures easier to debug.

• Bug Fixes
  • Populate ApiResponse with content, response, and status_code for 3xx/4xx/5xx and file-download paths.
  • Use response_as_text() and default to "API server error" only when the error body is empty.
  • Updated R generator template and regenerated sample clients.

^{Written for commit 0de41cf. Summary will update on new commits.}

[mattpollock]

local_var_resp$response can be a raw vector, meaning that the length(local_var_resp$response) is often greater than 1. This causes R errors because then local_var_resp$response == "" evaluates to a logical vector, but an if condition needs a logical scalar.

[mattpollock]

based on AI feedback I updated this to || all(local_var_resp$response == "")

[cubic-dev-ai]

4 issues found across 10 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="samples/client/echo_api/r/R/header_api.R">

<violation number="1" location="samples/client/echo_api/r/R/header_api.R:180">
P2: 5xx error handling can throw if response_as_text() returns NA (non-text body), because `local_var_error_msg == ""` yields NA and makes the `if` condition invalid.</violation>
</file>

<file name="samples/client/echo_api/r/R/body_api.R">

<violation number="1" location="samples/client/echo_api/r/R/body_api.R:261">
P2: 5xx error handling can throw when response_as_text returns NA; `local_var_error_msg == ""` yields NA and the `if` crashes for binary/invalid response bodies.</violation>
</file>

<file name="samples/client/echo_api/r/R/form_api.R">

<violation number="1" location="samples/client/echo_api/r/R/form_api.R:192">
P2: 5xx error handling can crash when response_as_text() yields character(0) or NA (empty/invalid body), because `local_var_error_msg == ""` makes the `if` condition throw instead of returning a fallback error response.</violation>
</file>

<file name="modules/openapi-generator/src/main/resources/r/api.mustache">

<violation number="1" location="modules/openapi-generator/src/main/resources/r/api.mustache:563">
P1: Primitive success path constructs ApiResponse with undefined variables (`content`, `resp`), causing runtime error and discarding the wrapper.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}