Regression: ‘roxygen2’ 7.3.0 fails to parse name of S3 method for class `{`

[klmr]

MWE:

dir.create('test/R', recursive = TRUE)
writeLines(
    r'[f = function (x) UseMethod('f')
`f.(` = function (x) x
`f.{` = function (x) x]',
    'test/R/test.r'
)

desc = list(
    Package = 'Test',
    Version = '0.0.1',
    License = 'MIT = file',
    Description = 'For testing.',
    Title = 'For Testing',
    `Authors@R` = 'person("F", "L", role = c("cre", "aut"))'
)
write.dcf(desc, 'test/DESCRIPTION')

roxygen2::roxygenize('test')

This leads to:

First time using roxygen2. Upgrading automatically...
Setting `RoxygenNote` to "7.3.0"
✖ roxygen2 requires "Encoding: UTF-8"
ℹ Current encoding is NA
ℹ Loading Test
Error in `map2()`:
ℹ In index: 1.
ℹ With name: f.{.
Caused by error in `glue()`:
! Unterminated quote (`)
Run `rlang::last_trace()` to see where the error occurred.

rlang::last_trace(drop = FALSE):

<error/purrr_error_indexed>
Error in `map2()`:
ℹ In index: 1.
ℹ With name: f.{.
Caused by error in `glue()`:
! Unterminated quote (`)
---
Backtrace:
     ▆
  1. ├─roxygen2::roxygenize("test")
  2. │ └─base::lapply(...)
  3. │   ├─roxygen2 (local) FUN(X[[i]], ...)
  4. │   └─roxygen2:::roclet_process.roclet_namespace(X[[i]], ...)
  5. │     └─roxygen2:::warn_missing_s3_exports(blocks, env)
  6. │       └─purrr::map2(undocumented, messages, warn_roxy_function)
  7. │         └─purrr:::map2_("list", .x, .y, .f, ..., .progress = .progress)
  8. │           ├─purrr:::with_indexed_errors(...)
  9. │           │ └─base::withCallingHandlers(...)
 10. │           ├─purrr:::call_with_cleanup(...)
 11. │           └─roxygen2 (local) .f(.x[[i]], .y[[i]], ...)
 12. │             └─roxygen2:::warn_roxy(file, line, message, parent = parent, envir = envir)
 13. │               └─cli::cli_inform(message, parent = parent, .envir = envir)
 14. │                 ├─rlang::inform(format_message(message, .envir = envir), ...)
 15. │                 │ └─message %||% ""
 16. │                 └─cli::format_message(message, .envir = .envir)
 17. │                   ├─cli::cli_fmt(...)
 18. │                   │ └─cli:::cli__rec(expr)
 19. │                   └─(function() {...
 20. │                     └─cli::cli_bullets(message, .envir = .envir)
 21. │                       ├─cli:::cli__message(...)
 22. │                       │ └─"id" %in% names(args)
 23. │                       ├─base::structure(lapply(text, glue_cmd, .envir = .envir), names = names(text))
 24. │                       └─base::lapply(text, glue_cmd, .envir = .envir)
 25. │                         └─cli (local) FUN(X[[i]], ...)
 26. │                           └─cli:::glue(...)
 27. └─base::.handleSimpleError(...)
 28.   └─purrr (local) h(simpleError(msg, call))
 29.     └─cli::cli_abort(...)
 30.       └─rlang::abort(...)

The offending package code is:

f = function (x) UseMethod('f')

`f.(` = function (x) x

`f.{` = function (x) x

Note that f.( is accepted, only f.{ causes an error.

The usage in actual code (in the ‘box’ package) needs this to dispatch on the type of an unevaluated R expression for an AST walker.

[klmr]

I should mention that this breaks a package on CRAN. It was presumably not caught by the revdep checks because it’s only a build dependency (and hence “Suggests”).

[hadley]

And now on CRAN 😄