[SPARK-20105][TESTS][R] Add tests for checkType and type string in structField in R

[HyukjinKwon]

What changes were proposed in this pull request?

It seems checkType and the type string in structField are not being tested closely. This string format currently seems SparkR-specific (see

spark/sql/core/src/main/scala/org/apache/spark/sql/api/r/SQLUtils.scala

Lines 93 to 131 in d1f6c64

	def getSQLDataType(dataType: String): DataType = {
	dataType match {
	case "byte" => org.apache.spark.sql.types.ByteType
	case "integer" => org.apache.spark.sql.types.IntegerType
	case "float" => org.apache.spark.sql.types.FloatType
	case "double" => org.apache.spark.sql.types.DoubleType
	case "numeric" => org.apache.spark.sql.types.DoubleType
	case "character" => org.apache.spark.sql.types.StringType
	case "string" => org.apache.spark.sql.types.StringType
	case "binary" => org.apache.spark.sql.types.BinaryType
	case "raw" => org.apache.spark.sql.types.BinaryType
	case "logical" => org.apache.spark.sql.types.BooleanType
	case "boolean" => org.apache.spark.sql.types.BooleanType
	case "timestamp" => org.apache.spark.sql.types.TimestampType
	case "date" => org.apache.spark.sql.types.DateType
	case r"\Aarray<(.+)${elemType}>\Z" =>
	org.apache.spark.sql.types.ArrayType(getSQLDataType(elemType))
	case r"\Amap<(.+)${keyType},(.+)${valueType}>\Z" =>
	if (keyType != "string" && keyType != "character") {
	throw new IllegalArgumentException("Key type of a map must be string or character")
	}
	org.apache.spark.sql.types.MapType(getSQLDataType(keyType), getSQLDataType(valueType))
	case r"\Astruct<(.+)${fieldsStr}>\Z" =>
	if (fieldsStr(fieldsStr.length - 1) == ',') {
	throw new IllegalArgumentException(s"Invalid type $dataType")
	}
	val fields = fieldsStr.split(",")
	val structFields = fields.map { field =>
	field match {
	case r"\A(.+)${fieldName}:(.+)${fieldType}\Z" =>
	createStructField(fieldName, fieldType, true)
	case _ => throw new IllegalArgumentException(s"Invalid type $dataType")
	}
	}
	createStructType(structFields)
	case _ => throw new IllegalArgumentException(s"Invalid type $dataType")
	}
	}

) but resembles SQL type definition.

Therefore, it seems nicer if we test positive/negative cases in R side.

How was this patch tested?

Unit tests in test_sparkSQL.R.

[HyukjinKwon]

cc @felixcheung, this adds the tests for the current status. Probably, let me try to investigate and propose the changes about the type definition thing we talked about later. I guess the branch is going to be cut out soon.

This PR only adds the positive/negative test cases for both structField and checkType.

[SparkQA]

Test build #75249 has finished for PR 17439 at commit b841ab3.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #75251 has finished for PR 17439 at commit 32ba2e1.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[felixcheung]

merged to master, thanks!