[SPARK-12232][SPARKR] New R API for read.table to avoid name conflict

shivaram sorry it took longer to fix some conflicts, this is the change to add an alias for `table`

Author: felixcheung <felixcheung_m@hotmail.com>

Closes #10406 from felixcheung/readtable.

4 files changed, 17 insertions, 20 deletions

diff --git a/R/pkg/NAMESPACE b/R/pkg/NAMESPACE
index 7739e9ea86..00634c1a70 100644
--- a/R/pkg/NAMESPACE
+++ b/R/pkg/NAMESPACE
@@ -280,7 +280,7 @@ export("as.DataFrame",
        "read.text",
        "sql",
        "str",
-       "table",
+       "tableToDF",
        "tableNames",
        "tables",
        "uncacheTable")
diff --git a/R/pkg/R/SQLContext.R b/R/pkg/R/SQLContext.R
index 99679b4a77..16a2578678 100644
--- a/R/pkg/R/SQLContext.R
+++ b/R/pkg/R/SQLContext.R
@@ -352,6 +352,8 @@ sql <- function(sqlContext, sqlQuery) {
 #' @param sqlContext SQLContext to use
 #' @param tableName The SparkSQL Table to convert to a DataFrame.
 #' @return DataFrame
+#' @rdname tableToDF
+#' @name tableToDF
 #' @export
 #' @examples
 #'\dontrun{
@@ -360,15 +362,14 @@ sql <- function(sqlContext, sqlQuery) {
 #' path <- "path/to/file.json"
 #' df <- read.json(sqlContext, path)
 #' registerTempTable(df, "table")
-#' new_df <- table(sqlContext, "table")
+#' new_df <- tableToDF(sqlContext, "table")
 #' }
 
-table <- function(sqlContext, tableName) {
+tableToDF <- function(sqlContext, tableName) {
   sdf <- callJMethod(sqlContext, "table", tableName)
   dataFrame(sdf)
 }
 
-
 #' Tables
 #'
 #' Returns a DataFrame containing names of tables in the given database.
diff --git a/R/pkg/inst/tests/testthat/test_context.R b/R/pkg/inst/tests/testthat/test_context.R
index 92dbd575c2..3b14a497b4 100644
--- a/R/pkg/inst/tests/testthat/test_context.R
+++ b/R/pkg/inst/tests/testthat/test_context.R
@@ -24,11 +24,11 @@ test_that("Check masked functions", {
   func <- lapply(masked, function(x) { capture.output(showMethods(x))[[1]] })
   funcSparkROrEmpty <- grepl("\\(package SparkR\\)$|^$", func)
   maskedBySparkR <- masked[funcSparkROrEmpty]
-  expect_equal(length(maskedBySparkR), 18)
-  expect_equal(sort(maskedBySparkR), sort(c("describe", "cov", "filter", "lag", "na.omit",
-                                            "predict", "sd", "var", "colnames", "colnames<-",
-                                            "intersect", "rank", "rbind", "sample", "subset",
-                                            "summary", "table", "transform")))
+  namesOfMasked <- c("describe", "cov", "filter", "lag", "na.omit", "predict", "sd", "var",
+                     "colnames", "colnames<-", "intersect", "rank", "rbind", "sample", "subset",
+                     "summary", "transform")
+  expect_equal(length(maskedBySparkR), length(namesOfMasked))
+  expect_equal(sort(maskedBySparkR), sort(namesOfMasked))
   # above are those reported as masked when `library(SparkR)`
   # note that many of these methods are still callable without base:: or stats:: prefix
   # there should be a test for each of these, except followings, which are currently "broken"
@@ -36,8 +36,9 @@ test_that("Check masked functions", {
                                         any(grepl("=\"ANY\"", capture.output(showMethods(x)[-1])))
                                       }))
   maskedCompletely <- masked[!funcHasAny]
-  expect_equal(length(maskedCompletely), 4)
-  expect_equal(sort(maskedCompletely), sort(c("cov", "filter", "sample", "table")))
+  namesOfMaskedCompletely <- c("cov", "filter", "sample")
+  expect_equal(length(maskedCompletely), length(namesOfMaskedCompletely))
+  expect_equal(sort(maskedCompletely), sort(namesOfMaskedCompletely))
 })
 
 test_that("repeatedly starting and stopping SparkR", {
diff --git a/R/pkg/inst/tests/testthat/test_sparkSQL.R b/R/pkg/inst/tests/testthat/test_sparkSQL.R
index 6610734cf4..14d40d5066 100644
--- a/R/pkg/inst/tests/testthat/test_sparkSQL.R
+++ b/R/pkg/inst/tests/testthat/test_sparkSQL.R
@@ -335,7 +335,6 @@ writeLines(mockLinesMapType, mapTypeJsonPath)
 test_that("Collect DataFrame with complex types", {
   # ArrayType
   df <- read.json(sqlContext, complexTypeJsonPath)
-
   ldf <- collect(df)
   expect_equal(nrow(ldf), 3)
   expect_equal(ncol(ldf), 3)
@@ -490,19 +489,15 @@ test_that("insertInto() on a registered table", {
   unlink(parquetPath2)
 })
 
-test_that("table() returns a new DataFrame", {
+test_that("tableToDF() returns a new DataFrame", {
   df <- read.json(sqlContext, jsonPath)
   registerTempTable(df, "table1")
-  tabledf <- table(sqlContext, "table1")
+  tabledf <- tableToDF(sqlContext, "table1")
   expect_is(tabledf, "DataFrame")
   expect_equal(count(tabledf), 3)
+  tabledf2 <- tableToDF(sqlContext, "table1")
+  expect_equal(count(tabledf2), 3)
   dropTempTable(sqlContext, "table1")
-
-  # nolint start
-  # Test base::table is working
-  #a <- letters[1:3]
-  #expect_equal(class(table(a, sample(a))), "table")
-  # nolint end
 })
 
 test_that("toRDD() returns an RRDD", {