CsvFileWriter.writeRows writes line terminator even when passed list or sequence is empty #122
Description
Describe the bug
CsvFileWriter.writeRows(rows: List<List<Any?>>) and CsvFileWriter.writeRows(rows: Sequence<List<Any?>>) write configured ctx.lineTerminator when the passed list or sequence argument has no elements. This results in a CSV file with empty lines in between, e.g.:
a,b,c
foo1,bar1,baz1
foo2,bar2,baz2
foo3,bar3,baz3
foo4,bar4,baz4
To Reproduce
- Open a CSV writer.
- Call CsvFileWriter.writeRows() with either an empty list or an empty sequence.
Here is a code snippet on how to reproduce the issue:
val headers = listOf("a","b","c")
val rows1 = listOf(
listOf("foo1","bar1","baz1"),
listOf("foo2","bar2","baz2")
)
val rows2 = emptyList<List<Any?>>()
val rows3 = listOf(
listOf("foo3","bar3","baz3"),
listOf("foo4","bar4","baz4")
)
csvWriter { lineTerminator = "\n" }.open("example.csv") {
writeRow(headers)
writeRows(rows1)
writeRows(rows2) //Here the CSV file will have the configured line terminator added even though the list is empty.
writeRows(rows3)
}
Expected behavior
A CSV file without empty rows in between. For example:
a,b,c
foo1,bar1,baz1
foo2,bar2,baz2
foo3,bar3,baz3
foo4,bar4,baz4
Environment
- kotlin-csv version 1.9.0
- java version 17
- OS: macOS
I will try to create a PR with the fix once I have some time.