[SPARK-7714] [SPARKR] SparkR tests should use more specific expectations than expect_true

1. Update the pattern 'expect_true(a == b)' to 'expect_equal(a, b)'.
2. Update the pattern 'expect_true(inherits(a, b))' to 'expect_is(a, b)'.
3. Update the pattern 'expect_true(identical(a, b))' to 'expect_identical(a, b)'.

Author: Sun Rui <[email protected]>

Closes apache#7152 from sun-rui/SPARK-7714 and squashes the following commits:

8ad2440 [Sun Rui] Fix test case errors.
8fe9f0c [Sun Rui] Update the pattern 'expect_true(identical(a, b))' to 'expect_identical(a, b)'.
f1b8005 [Sun Rui] Update the pattern 'expect_true(inherits(a, b))' to 'expect_is(a, b)'.
f631e94 [Sun Rui] Update the pattern 'expect_true(a == b)' to 'expect_equal(a, b)'.

Author: Sun Rui

R/pkg/inst/tests/test_binaryFile.R

@@ -82,7 +82,7 @@ test_that("saveAsObjectFile()/objectFile() works with multiple paths", {
   saveAsObjectFile(rdd2, fileName2)
 
   rdd <- objectFile(sc, c(fileName1, fileName2))
-  expect_true(count(rdd) == 2)
+  expect_equal(count(rdd), 2)
 
   unlink(fileName1, recursive = TRUE)
   unlink(fileName2, recursive = TRUE)

R/pkg/inst/tests/test_binary_function.R

@@ -38,13 +38,13 @@ test_that("union on two RDDs", {
   union.rdd <- unionRDD(rdd, text.rdd)
   actual <- collect(union.rdd)
   expect_equal(actual, c(as.list(nums), mockFile))
-  expect_true(getSerializedMode(union.rdd) == "byte")
+  expect_equal(getSerializedMode(union.rdd), "byte")
 
   rdd<- map(text.rdd, function(x) {x})
   union.rdd <- unionRDD(rdd, text.rdd)
   actual <- collect(union.rdd)
   expect_equal(actual, as.list(c(mockFile, mockFile)))
-  expect_true(getSerializedMode(union.rdd) == "byte")
+  expect_equal(getSerializedMode(union.rdd), "byte")
 
   unlink(fileName)
 })

R/pkg/inst/tests/test_includeJAR.R

@@ -31,7 +31,7 @@ runScript <- function() {
 test_that("sparkJars tag in SparkContext", {
   testOutput <- runScript()
   helloTest <- testOutput[1]
-  expect_true(helloTest == "Hello, Dave")
+  expect_equal(helloTest, "Hello, Dave")
   basicFunction <- testOutput[2]
-  expect_true(basicFunction == 4L)
+  expect_equal(basicFunction, "4")
 })

R/pkg/inst/tests/test_parallelize_collect.R

@@ -57,7 +57,7 @@ test_that("parallelize() on simple vectors and lists returns an RDD", {
              strListRDD2)
 
   for (rdd in rdds) {
-    expect_true(inherits(rdd, "RDD"))
+    expect_is(rdd, "RDD")
     expect_true(.hasSlot(rdd, "jrdd")
                 && inherits(rdd@jrdd, "jobj")
                 && isInstanceOf(rdd@jrdd, "org.apache.spark.api.java.JavaRDD"))

R/pkg/inst/tests/test_rdd.R

@@ -33,9 +33,9 @@ test_that("get number of partitions in RDD", {
 })
 
 test_that("first on RDD", {
-  expect_true(first(rdd) == 1)
+  expect_equal(first(rdd), 1)
   newrdd <- lapply(rdd, function(x) x + 1)
-  expect_true(first(newrdd) == 2)
+  expect_equal(first(newrdd), 2)
 })
 
 test_that("count and length on RDD", {