[BUG] ActionSerializerSuite has 3 failing unit tests in the master branch

Bug

Describe the problem

Following unit tests fail:

• Metadata (with all defaults)
• Metadata - json serialization/deserialization
• Metadata with empty createdTime- json serialization/deserialization

Steps to reproduce

git checkout master
build/sbt "testOnly org.apache.spark.sql.delta.ActionSerializerSuite"

 Metadata (with all defaults) - json serialization/deserialization *** FAILED *** (623 milliseconds)
[info]   "{"metaData":{"id":"[10daabbc-d843-4fe4-abe5-0ccb83ba681e]","format":{"provide..." did not equal "{"metaData":{"id":"[testId]","format":{"provide..." (ActionSerializerSuite.scala:344)
[info]   Analysis:
[info]   "{"metaData":{"id":"[10daabbc-d843-4fe4-abe5-0ccb83ba681e]","format":{"provide..." -> "{"metaData":{"id":"[testId]","format":{"provide..."

============================================================
[info] Tests: succeeded 25, failed 3, canceled 0, ignored 0, pending 0
[info] *** 3 TESTS FAILED ***
[error] Failed tests:
[error]         org.apache.spark.sql.delta.ActionSerializerSuite
[error] (core / Test / testOnly) sbt.TestsFailedException: Tests unsuccessful
[error] Total time: 24 s, completed Jul 21, 2022 9:56:50 AM
➜  delta git:(master)$ build/sbt "testOnly org.apache.spark.sql.delta.ActionSerializerSuite"

Observed results

Expected results

Further details

Environment information

• Delta Lake version:
• Spark version:
• Scala version:

Willingness to contribute

The Delta Lake Community encourages bug fix contributions. Would you or another member of your organization be willing to contribute a fix for this bug to the Delta Lake code base?

• Yes. I can contribute a fix for this bug independently.
• Yes. I would be willing to contribute a fix for this bug with guidance from the Delta Lake community.
• No. I cannot contribute a bug fix at this time.

[bogdanmrusu]

The id for metadata is build taking Utils.isTesting into account. Check this: https://github.com/delta-io/delta/blob/2871e550eabd9e4956aca1b02baeb20635a66931/core/src/main/scala/org/apache/spark/sql/delta/actions/actions.scala#L439

The isTesting is basically this: System.getenv("SPARK_TESTING") != null || System.getProperty(IS_TESTING.key) != null

With no extra environmental variables, the 3 tests are failing exactly as you described. If I execute export SPARK_TESTING=true and then I run the tests, they all pass.

@ganeshchand should we close this?

[zsxwing]

@scottsand-db could you review all of Metadata creation and make sure they are created in test body rather than outside?