Replace missing fields with empty string (#117)

* add empty string option to InsufficientFieldsRowBehaviour enum

* handle empty string option inside csvfile reader

* add tests to handle insufficient rows with empty string option

* remove unneeded change

* change comment to better reflect the option

* remove unneeded change

* simplify adding empty strings to rows

* fix bad var name

* update readme

README.md

@@ -176,7 +176,7 @@ val tsvReader = csvReader {
 | autoRenameDuplicateHeaders | `false` | Whether to auto rename duplicate headers or throw an exception. |
 | ~~skipMissMatchedRow~~ | `false` | Deprecated. Replace with appropriate values in `excessFieldsRowBehaviour` and `insufficientFieldsRowBehaviour`, e.g. both set to `IGNORE`. ~~Whether to skip an invalid row. If `ignoreExcessCols` is true, only rows with less than the expected number of columns will be skipped.~~ |
 | excessFieldsRowBehaviour | `ERROR` | Behaviour to use when a row has more fields (columns) than expected. `ERROR` (default), `IGNORE` (skip the row) or `TRIM` (remove the excess fields at the end of the row to match the expected number of fields). |
-| insufficientFieldsRowBehaviour | `ERROR` | Behaviour to use when a row has fewer fields (columns) than expected. `ERROR` (default), `IGNORE` (skip the row).  |
+| insufficientFieldsRowBehaviour | `ERROR` | Behaviour to use when a row has fewer fields (columns) than expected. `ERROR` (default), `IGNORE` (skip the row) or `EMPTY_STRING` (replace missing fields with an empty string). |
 
 ### CSV Write examples
 

src/commonMain/kotlin/com/github/doyaaaaaken/kotlincsv/client/CsvFileReader.kt

@@ -62,6 +62,9 @@ class CsvFileReader internal constructor(
  } else if (numFieldsInRow != row.size) {
  if (ctx.skipMissMatchedRow || ctx.insufficientFieldsRowBehaviour == InsufficientFieldsRowBehaviour.IGNORE) {
  skipMismatchedRow(idx, row, numFieldsInRow)
+ } else if (ctx.insufficientFieldsRowBehaviour == InsufficientFieldsRowBehaviour.EMPTY_STRING) {
+ val numOfMissingFields = numFieldsInRow - row.size
+ row.plus(List(numOfMissingFields) { "" })
  } else {
  throw CSVFieldNumDifferentException(numFieldsInRow, row.size, idx + 1)
  }

src/commonMain/kotlin/com/github/doyaaaaaken/kotlincsv/dsl/context/CsvReaderContext.kt

@@ -100,7 +100,11 @@ enum class InsufficientFieldsRowBehaviour {
  /**
  * Ignore the row and skip to the next row
  */
- IGNORE
+ IGNORE,
+ /**
+ * Treat missing fields as an empty string
+ */
+ EMPTY_STRING
 }
 
 enum class ExcessFieldsRowBehaviour {

src/jvmTest/kotlin/com/github/doyaaaaaken/kotlincsv/client/CsvReaderTest.kt

@@ -184,7 +184,7 @@ class CsvReaderTest : WordSpec({
  "Trim row when reading csv with greater num of fields on a subsequent row" {
  val expected = listOf(listOf("a", "b"), listOf("c", "d"))
  val actual =
- csvReader{
+ csvReader {
  excessFieldsRowBehaviour = ExcessFieldsRowBehaviour.TRIM
  }.readAll(readTestDataFile("different-fields-num2.csv"))
 
@@ -196,7 +196,7 @@ class CsvReaderTest : WordSpec({
  "it should be be possible to skip rows with both excess and insufficient fields" {
  val expected = listOf(listOf("a", "b"))
  val actual =
- csvReader{
+ csvReader {
  excessFieldsRowBehaviour = ExcessFieldsRowBehaviour.IGNORE
  insufficientFieldsRowBehaviour = InsufficientFieldsRowBehaviour.IGNORE
  }.readAll(readTestDataFile("varying-column-lengths.csv"))
@@ -206,10 +206,36 @@ class CsvReaderTest : WordSpec({
  actual.size shouldBe 1
  }
  }
+ "it should be be possible to replace insufficient fields with strings and skip rows with excess fields" {
+ val expected = listOf(listOf("a", "b"), listOf("c", ""))
+ val actual =
+ csvReader {
+ excessFieldsRowBehaviour = ExcessFieldsRowBehaviour.IGNORE
+ insufficientFieldsRowBehaviour = InsufficientFieldsRowBehaviour.EMPTY_STRING
+ }.readAll(readTestDataFile("varying-column-lengths.csv"))
+
+ assertSoftly {
+ actual shouldBe expected
+ actual.size shouldBe 2
+ }
+ }
+ "it should be be possible to replace insufficient fields with strings and trim rows with excess fields" {
+ val expected = listOf(listOf("a", "b"), listOf("c", ""), listOf("d", "e"))
+ val actual =
+ csvReader {
+ excessFieldsRowBehaviour = ExcessFieldsRowBehaviour.TRIM
+ insufficientFieldsRowBehaviour = InsufficientFieldsRowBehaviour.EMPTY_STRING
+ }.readAll(readTestDataFile("varying-column-lengths.csv"))
+
+ assertSoftly {
+ actual shouldBe expected
+ actual.size shouldBe 3
+ }
+ }
  "it should be be possible to trim excess columns and skip insufficient row columns" {
- val expected = listOf(listOf("a", "b"), listOf("d","e"))
+ val expected = listOf(listOf("a", "b"), listOf("d", "e"))
  val actual =
- csvReader{
+ csvReader {
  excessFieldsRowBehaviour = ExcessFieldsRowBehaviour.TRIM
  insufficientFieldsRowBehaviour = InsufficientFieldsRowBehaviour.IGNORE
  }.readAll(readTestDataFile("varying-column-lengths.csv"))