cannot change value of locked binding

[kenahoo]

I've got a package that I'm testing, and I call getURL from the RCurl package in it. That function is imported, so my NAMESPACE has importFrom(RCurl,getURL) in it.

When I mock that out in my testing, I do this:

library(mockthat)

test_that("API works", {

  response <- data.frame(foo = 7)
  mock_response <- mockthat::mock(as.character(jsonlite::toJSON(response)))

  mockthat::with_mock(
    getURL=mock_response,
    {
      result <- myFunction()
    })

This fails with the following error, but only when I run under devtools::check() (it succeeds under devtools::test()):

not ok 1 API works
  Error: cannot change value of locked binding for 'getURL'
  Backtrace:
   1. mockthat::with_mock(...) test-yes.R:29:2
   2. base::lapply(mocks, set_mock)
   3. mockthat:::FUN(X[[i]], ...)
   4. mockthat:::do_assign(mock$name, mock$new_value, mock$env)
   5. base::assign(name, val, envir = env)
not ok 2 API works
  Error: cannot change value of locked binding for 'getURL'
  Backtrace:
   1. mockthat::with_mock(...) test-yes.R:29:2
   2. base::lapply(mocks, reset_mock) test-yes.R:29:2
   3. mockthat:::FUN(X[[i]], ...)
   4. mockthat:::do_assign(mock$name, mock$orig_value, mock$env)
   5. base::assign(name, val, envir = env)

Is there something I need to do differently for an imported function like this?

I'm using:

> packageVersion('mockthat')
[1] '0.2.6'

> cat(head(capture.output(sessionInfo()), 3), sep="\n")
R version 4.1.1 (2021-08-10)
Platform: x86_64-apple-darwin17.0 (64-bit)
Running under: macOS Big Sur 11.4

Apologies for not creating a proper reprex - it will take quite a while to slim down my package code to something isolated, and I'm also not sure how to demonstrate the problem without having a whole package structure.

[kenahoo]

I have also tried unlocking the environment during testing a few different ways, but haven't found anything that works:

unlockBinding("getURL", env=.getNamespace("RCurl"))
unlockBinding("getURL", env=.BaseNamespaceEnv)
unlockBinding("getURL", env=.getNamespace("mypackage"))

[kenahoo]

Hi @nbenn , have you had a chance to think about this? I'm also hitting it when I try to mock s3write_using from the aws.s3 package.

  Error in `assign(name, val, envir = env)`: cannot change value of locked binding for 's3write_using'
  Backtrace:
   1. mockthat::with_mock(...) test-io.r:15:2
   2. base::lapply(mocks, set_mock)
   3. mockthat:::FUN(X[[i]], ...)
   4. mockthat:::do_assign(mock$name, mock$new_value, mock$env)
   5. base::assign(name, val, envir = env)

[nbenn]

I'm very sorry for not having gotten back to you earlier! I tried to reproduce your issue (see nbenn/mockthat6) and I pushed a small fix that resolves the issue in that particular instance. Let me know if you're still having troubles and feel free to submit a PR to the mockthat6 repo if this does not yet cover your use-case. Let me know if your problem is solved, so that I can send an update to CRAN.

[kenahoo]

Thanks @nbenn - don't worry about the lag! I know attention is a precious resource.

I think this fix does the trick. I can now import functions like so

#' @importFrom aws.s3 s3write_using
#' @importFrom withr local_envvar

in my package code, and then do

mockthat::with_mock(
    s3write_using=mock_s3,
    local_envvar=mock_envvar,
    ...)

in my testing code, and it seems to work under both devtools::check() and devtools::test(). Thanks!

[kenahoo]

Hi @nbenn - any chance you can release a version to CRAN with this fix?

[kenahoo]

Looks like version 0.2.8, released 2022-11-01, includes this fix, so this ticket can be closed. Thanks again!