[SPARK-12393][SPARKR] Add read.text and write.text for SparkR

Add ```read.text``` and ```write.text``` for SparkR.
cc sun-rui felixcheung shivaram

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #10348 from yanboliang/spark-12393.

1 files changed, 21 insertions, 0 deletions

diff --git a/R/pkg/inst/tests/testthat/test_sparkSQL.R b/R/pkg/inst/tests/testthat/test_sparkSQL.R
index ebe8faa34c..eaf60beda3 100644
--- a/R/pkg/inst/tests/testthat/test_sparkSQL.R
+++ b/R/pkg/inst/tests/testthat/test_sparkSQL.R
@@ -1497,6 +1497,27 @@ test_that("read/write Parquet files", {
   unlink(parquetPath4)
 })
 
+test_that("read/write text files", {
+  # Test write.df and read.df
+  df <- read.df(sqlContext, jsonPath, "text")
+  expect_is(df, "DataFrame")
+  expect_equal(colnames(df), c("value"))
+  expect_equal(count(df), 3)
+  textPath <- tempfile(pattern = "textPath", fileext = ".txt")
+  write.df(df, textPath, "text", mode="overwrite")
+
+  # Test write.text and read.text
+  textPath2 <- tempfile(pattern = "textPath2", fileext = ".txt")
+  write.text(df, textPath2)
+  df2 <- read.text(sqlContext, c(textPath, textPath2))
+  expect_is(df2, "DataFrame")
+  expect_equal(colnames(df2), c("value"))
+  expect_equal(count(df2), count(df) * 2)
+
+  unlink(textPath)
+  unlink(textPath2)
+})
+
 test_that("describe() and summarize() on a DataFrame", {
   df <- read.json(sqlContext, jsonPath)
   stats <- describe(df, "age")