Platform (all, jvm, js): all
Extension (none, kotlin 1.3): none

Code related feature

expect(path).toBeAnEmptyDirectory()

//instead of

expect(path)
  .toBeADirectory()
  .feature("findFirstFile", { Files.list(this).use { it.findFirst() } }) {
    isEmpty()
  }

Following the things you need to do:

logic

• extend PathAssertions with a function toBeEmptyDirectory (see other functions as a guideline)
• implement toBeEmptyDirectory in DefaultPathAssertions.kt -- bonus use newDirectoryStream instead and list all files as failureHint in case the iterator.hasNext()

api-fluent

• provide a fun toBeAnEmptyDirectory in a new file called pathExpectations.kt (see for instance isDirectory in pashAssertions.kt as a guideline)
• add @since 0.16.0 (adapt to current milestone) to KDOC
• add toBeAnEmptyDirectory to PathExpectationsSpec in specs-common adopt the spec in api-fluent

api-infix

• provide a fun toBe which expects anEmptyDirectory in a new file called pathExpectations.kt (see toBe aDirectory in pathAssertions.kt as a guideline)
• add @since 0.16.0 (adapt to current milestone) to KDOC
• add toBeAnEmptyDirectory to PathExpectationsSpec in specs-common adopt the spec in api-infix

Your first contribution?

• Write a comment I'll work on this if you would like to take this issue over.
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