Work around visible bindings notes in R CMD check

Closes #40

NEWS.md

@@ -1,5 +1,8 @@
 # coro (development version)
 
+* Generators and async functions assigned in namespaces no
+  longer produce R CMD check notes about visible bindings (#40).
+
 # coro 1.0.5
 
 * Async functions created by `coro::async()` now return their

R/generator.R

@@ -130,6 +130,10 @@ generator0 <- function(fn, type = "generator") {
     `_private`$caller_env <- base::parent.frame()
 
     base::local(envir = `_private`, {
+      generator_env <- environment()$generator_env
+      caller_env <- environment()$caller_env
+      exits <- NULL
+
       info <- machine_info(type, env = caller_env)
 
       # Generate the state machine lazily at runtime

tests/testthat/test-async.R

@@ -287,3 +287,13 @@ test_that("async function returns invisibly (#46)", {
   })
   expect_invisible(fn())
 })
+
+test_that("async functions do not cause CMD check notes (#40)", {
+  skip_on_cran()
+  expect_silent(
+    invisible(compiler::cmpfun(
+      async(function() NULL),
+      options = list(suppressAll = FALSE)
+    ))
+  )
+})

tests/testthat/test-generator.R

@@ -329,3 +329,13 @@ test_that("stepping into generators returns visibly (#46)", {
   expect_visible(abc())
   expect_visible(abc())
 })
+
+test_that("generators do not cause CMD check notes (#40)", {
+  skip_on_cran()
+  expect_silent(
+    invisible(compiler::cmpfun(
+      generator(function() NULL),
+      options = list(suppressAll = FALSE)
+    ))
+  )
+})