[SPARK-46721][CORE][TESTS] Make gpu fraction tests more robust

[wbo4958]

What changes were proposed in this pull request?

When cherry-picking #43494 back to branch 3.5 #44690,
I ran into the issue that some tests for Scala 2.12 failed when comparing two maps. It turned out that the function compareMaps is not so robust for scala 2.12 and scala 2.13.

• scala 2.13

Welcome to Scala 2.13.12 (OpenJDK 64-Bit Server VM, Java 17.0.9).
Type in expressions for evaluation. Or try :help.

scala> def compareMaps(lhs: Map[String, Double], rhs: Map[String, Double],
     |                   eps: Double = 0.00000001): Boolean = {
     |     lhs.size == rhs.size &&
     |       lhs.zip(rhs).forall { case ((lName, lAmount), (rName, rAmount)) =>
     |         lName == rName && (lAmount - rAmount).abs < eps
     |       }
     | }
     |   
     | import scala.collection.mutable.HashMap
     | val resources = Map("gpu" -> Map("a" -> 1.0, "b" -> 2.0, "c" -> 3.0, "d"-> 4.0))
     | val mapped = resources.map { case (rName, addressAmounts) =>
     |  rName -> HashMap(addressAmounts.toSeq.sorted: _*) 
     | }
     | 
     | compareMaps(resources("gpu"), mapped("gpu").toMap)
def compareMaps(lhs: Map[String,Double], rhs: Map[String,Double], eps: Double): Boolean
import scala.collection.mutable.HashMap
val resources: scala.collection.immutable.Map[String,scala.collection.immutable.Map[String,Double]] = Map(gpu -> Map(a -> 1.0, b -> 2.0, c -> 3.0, d -> 4.0))
val mapped: scala.collection.immutable.Map[String,scala.collection.mutable.HashMap[String,Double]] = Map(gpu -> HashMap(a -> 1.0, b -> 2.0, c -> 3.0, d -> 4.0))
val res0: Boolean = true

• scala 2.12

Welcome to Scala 2.12.14 (OpenJDK 64-Bit Server VM, Java 17.0.9).
Type in expressions for evaluation. Or try :help.

scala> def compareMaps(lhs: Map[String, Double], rhs: Map[String, Double],
     |                   eps: Double = 0.00000001): Boolean = {
     |     lhs.size == rhs.size &&
     |       lhs.zip(rhs).forall { case ((lName, lAmount), (rName, rAmount)) =>
     |         lName == rName && (lAmount - rAmount).abs < eps
     |       }
     | }
compareMaps: (lhs: Map[String,Double], rhs: Map[String,Double], eps: Double)Boolean

scala> import scala.collection.mutable.HashMap
import scala.collection.mutable.HashMap

scala> val resources = Map("gpu" -> Map("a" -> 1.0, "b" -> 2.0, "c" -> 3.0, "d"-> 4.0))
resources: scala.collection.immutable.Map[String,scala.collection.immutable.Map[String,Double]] = Map(gpu -> Map(a -> 1.0, b -> 2.0, c -> 3.0, d -> 4.0))

scala> val mapped = resources.map { case (rName, addressAmounts) =>
     |   rName -> HashMap(addressAmounts.toSeq.sorted: _*) 
     | }
mapped: scala.collection.immutable.Map[String,scala.collection.mutable.HashMap[String,Double]] = Map(gpu -> Map(b -> 2.0, d -> 4.0, a -> 1.0, c -> 3.0))

scala> compareMaps(resources("gpu"), mapped("gpu").toMap)
res0: Boolean = false

The same code bug got different results for Scala 2.12 and Scala 2.13. This PR tried to rework compareMaps to make tests pass for both scala 2.12 and scala 2.13

Why are the changes needed?

Some users may back-port #43494 to some older branch for scala 2.12 and will run into the same issue. It's just trivial work to make the GPU fraction tests compatible with Scala 2.12 and Scala 2.13

Does this PR introduce any user-facing change?

No

How was this patch tested?

Make sure all the CI pipelines pass

Was this patch authored or co-authored using generative AI tooling?

No

[wbo4958]

Hi @tgravescs, Could you help to review it? Thx very much.

[Ngone51]

How about:

lhs.size == rhs.size && lhs.forall { case (lName, lAmount) =>
  rhs.get(lName).exists(rAmount => (lAmount - rAmount).abs < eps)
}

we can avoid sort this way.

[wbo4958]

Cool. Thx. Done.

[Ngone51]

LGTM

[Ngone51]

Thanks, merged to master!