Update Imports from Blanket to Selective Import for Improved Code Maintainability (#5988)

* Changed blanket imports to selective imports

* removed quotes

* alphabetize

* removed time from imports

* Update test.data.table.R

* added name to Authors@R

---------

Co-authored-by: nitish jha <[email protected]>
Co-authored-by: Michael Chirico <[email protected]>

Author: 3 people

DESCRIPTION

@@ -82,5 +82,6 @@ Authors@R: c(
   person("Josh","O'Brien",         role="ctb"),
   person("Dereck","de Mezquita",   role="ctb"),
   person("Michael","Czekanski",    role="ctb"),
-  person("Dmitry", "Shemetov",     role="ctb")
+  person("Dmitry", "Shemetov",     role="ctb"),
+  person("Nitish", "Jha",          role="ctb")
   )

NAMESPACE

@@ -1,7 +1,7 @@
 useDynLib("data_table", .registration=TRUE)
 
 ## For S4-ization
-import(methods)
+importFrom(methods, "S3Part<-", slotNames)
 exportClasses(data.table, IDate, ITime)
 ##
 
@@ -130,11 +130,11 @@ S3method(melt, default)
 # and many packges on CRAN call dcast.data.table() and/or melt.data.table() directly. See #3082.
 export(melt.data.table, dcast.data.table)
 
-import(utils)
+importFrom(utils, capture.output, contrib.url, download.file, flush.console, getS3method, head, packageVersion, tail, untar, unzip)
 export(update_dev_pkg)
 S3method(tail, data.table)
 S3method(head, data.table)
-import(stats)
+importFrom(stats, as.formula, na.omit, setNames, terms)
 S3method(na.omit, data.table)
 
 S3method(as.data.table, xts)

R/test.data.table.R

@@ -191,7 +191,7 @@ test.data.table = function(script="tests.Rraw", verbose=FALSE, pkg=".", silent=F
   }
 
   # There aren't any errors, so we can use up 11 lines for the timings table
-  nTest = RSS = NULL  # to avoid 'no visible binding' note
+  time = nTest = RSS = NULL  # to avoid 'no visible binding' note
   timings = env$timings[nTest>0]
   if (!memtest) {
     ans = head(timings[if (dev) -1L else TRUE][order(-time)], 10L)[,RSS:=NULL]   # exclude id 1 in dev as that includes JIT