TableDiff

A Scala based (but usable from Java and other JVM languages) utility for finding a diff of 2 tables, taking account of their structure.

Available on maven central

There are lots of options in the library functions, so for simple usage, you probably want to create little util functions. e.g. to compare 2 lists of cases classes.

import org.suecarter.tablediff._
def listsDiffString(leftList: Iterable[Product], rightList: Iterable[Product]): String = {
  def listReport(list: Iterable[Product]) =
    ReportContent(
      columnHeaders = Seq(list.headOption.getOrElse(Nil).productElementNames.toSeq), // Scala 2.13+ for this
      mainData = list.map(x => x.productIterator.toSeq).toSeq,
    )
  StringTableDiff.diffReportToString(
    TableDiff.produceReportDiff(listReport(leftList), listReport(rightList)),
  )
}

case class A(b: Int, c: String)
listsDiffString(Seq(A(1,"x"), A(2,"y"), A(4, "c")), Seq(A(1,"x"), A(2,"z"), A(3, "c"))) 

+---------------------+
|b         |c         |
+---------------------+
|1         |x         |
|2         |[-y-]{+z+}|
|[-4-]{+3+}|c         |
+---------------------+

For usage example in java. (See this in the class org.suecarter.javatablediffexample.JavaTableDiffTest.java, the testDemo test)

Compare left table
+----+--------------+
|    |col1|col2|col3|
+----+--------------+
|row1|m1,1|m2,1|m3,1|
|row2|m1,2|m2,2|m3,2|
+----+--------------+

to right table
+----+---------------------+
|    |col1|col2|col2.5|col3|
+----+---------------------+
|row1|m1,x|m2,1|m2.5,1|m3,1|
|row2|m1,2|m2,2|m2.5,2|m3,2|
+----+---------------------+

Produces these diffs, showing us that the cell in row1,col1 has
changed from m1,1 to m1,x and a whole new column (col2.5) has 
been added.
+----+----------------------------------+
|    |col1         |col2|{+col2.5+}|col3|
+----+----------------------------------+
|row1|m1,[-1-]{+x+}|m2,1|{+m2.5,1+}|m3,1|
|row2|m1,2         |m2,2|{+m2.5,2+}|m3,2|
+----+----------------------------------+