Keeps last value of eval_code()/within()

NEWS.md

@@ -1,5 +1,9 @@
 # teal.code 0.6.1.9003
 
+### Enhancements
+
+* Code evaluation keeps the last evaluated expression in the `.Last.value` attribute of the environment.
+
 ### Bug fixes
 
 * Fix a problem detecting co-occurrences when expression has multiple lines.

R/qenv-eval_code.R

@@ -13,6 +13,8 @@
 #'
 #' @return
 #' `qenv` environment with `code/expr` evaluated or `qenv.error` if evaluation fails.
+#' The environment contains an attribute called `".Last.value"` which is the last evaluated value,
+#' similarly to [base::.Last.value].
 #'
 #' @examples
 #' # evaluate code in qenv
@@ -61,12 +63,12 @@ setMethod("eval_code", signature = c(object = "qenv.error"), function(object, co
     x <- withCallingHandlers(
       tryCatch(
         {
-          eval(current_call, envir = object@.xData)
-          if (!identical(parent.env([email protected]), parent.env(.GlobalEnv))) {
-            # needed to make sure that @.xData is always a sibling of .GlobalEnv
-            # could be changed when any new package is added to search path (through library or require call)
-            parent.env([email protected]) <- parent.env(.GlobalEnv)
-          }
+          # needed to make sure that @.xData inherits from .GlobalEnv
+          # could be changed when any new package is added to search path (through library or require call)
+          qenv_last_value <- eval(current_call, envir = object@.xData)
+          new_parent <- new.env(parent = parent.env(.GlobalEnv))
+          new_parent[[".Last.value"]] <- qenv_last_value
+          parent.env([email protected]) <- new_parent
           NULL
         },
         error = function(e) {

tests/testthat/test-qenv_eval_code.R

@@ -186,3 +186,10 @@ testthat::test_that("comments passed alone to eval_code that contain @linksto ta
     "x"
   )
 })
+
+testthat::test_that("eval_code keeps .Last.value as an attribute of the environment", {
+  q <- eval_code(qenv(), quote(x <- 1))
+  env <- parent.env(q)
+  testthat::expect_true(".Last.value" %in% names(env))
+  testthat::expect_equal(env$.Last.value, 1)
+})

tests/testthat/test-qenv_within.R

@@ -154,3 +154,10 @@ testthat::test_that("Code executed with integer shorthand (1L) is the same as or
   q <- within(qenv(), a <- 1L)
   testthat::expect_identical(get_code(q), "a <- 1L")
 })
+
+testthat::test_that("within keeps .Last.value as an attribute of the environment", {
+  q <- within(qenv(), x <- 1)
+  env <- parent.env(q)
+  testthat::expect_true(".Last.value" %in% names(env))
+  testthat::expect_equal(env$.Last.value, 1)
+})