Notable changes

ZIO

• Add tests of serialization for all ZIO data types and make Promise serializable (#1771) by @jakubjanecek
• Implement raceAll without folding with race(#1424) by @chikei
• Parameterized environment on zio.Canceler (#1763) by @ajaychandran
• Expose Executor as ExecutorService (#1745) by @jczuchnowski
• Suspend ZIO.as & ZStream.as again (#1822) by @neko-kai
• Fix #785, Fix #1441, prevent race condition on interrupted variable by moving interrupted into atomic state (#1792) by @neko-kai
• Add CancelableFuture (#1655) by @fsvehla
• Prevent ZIO.option from catching unchecked errors (#1870) by @darl
• Implement ZIO#timeoutFork (#1856) by @adamgfraser
• Add Meta Subtype to Cause (#1706) by @adamgfraser
• Make everything private that can / should be private (#1751) by @zezutom
• Allow custom behavior on inheritFiberRefs (#1879) by @mschuwalow
• Make sure that FiberRefs are inherited in ZIO.raceAll (#1902) by @mlangc

ZIO Test

In this release the internal representation of Spec has been changed to make all Specs effectual. This allows for performing effects on groups of tests in additional to individual tests. We expect this will not require any changes from most users but may be breaking for code that relies on some methods on Spec or the particular encoding of ZSpec. Please report any issues you notice!

• [Breaking] Moved package zio.test.mock to zio.test.environment (#1830) by @ioleo
• [Breaking] Renamed MockConsole, MockClock, MockSystem and MockRandom to Test* equivalents (within the moved package) (#1830) by @ioleo
• Added mocking framework under zio.test.mock package (#1830) by @ioleo
• Support shared managed resources (#1664) by @adamgfraser
• Added rendering of zio.test.mock.MockException defects in zio.test.DefaultTestReporter (#1830) by @ioleo
• Make failure a TestAspect (#1741) by @jaliss
• Add interrupt deadline to timeout TestAspect (#1824) by @LGLO
• Simplify TestAspect#around (#1718) by @adamgfraser
• Harden MockClock (#1885) by @adamgfraser
• Add fibertime to public api of MockClock (#1890) by @mschuwalow
• Implement multiple parameter function generators (#1893) by @adamgfraser
• Add Gen.anyUnicodeChar(#1901) by @regiskuckaertz

ZIO Stream

• Port ZStream.fromInputStream to StreamEffect (#1772) by @jsilva
• Fix Chunk.empty.toArray throws ClassCastException (#1797) by @wi101
• Add a method for converting ZStream[Byte] to a ZManaged[java.io.InputStream] (#1784) by @sideeffffect
• Add ZManaged.switchable (#1810) by @iravid
• Implement pure ZSink.ignoreWhile (#1820) by @vasilmkd
• Clear up some Chunk hotspots(#1825) by @iravid
• Back presssure in ZStream.effectAsync* (#1855) by @darl
• Reduce allocations in ZStream#unTake (#1861) by @vasilmkd
• Add ZStream#toQueueUnbounded (#1860) by @vasilmkd
• Add ChunkN to ZStream (#1795) by @LukaszByczynski
• Optimize ChunkN (#1881) by @mvv
• Add ZStream combinators for dropping/sliding buffers (#1685) by @vasilmkd
• Align StreamChunk and Chunk's foldings methods with ZStream (#1778) by @kamilkloch

Documentation

• Enrich ZIO Test documentation (#1800) by @almendar
• Fix Contributing page (#1791) by @softinio
• Other docs improvements by @reibitto @asakaev @LGLO @FelAl