The description should be completely rewritten as as of now it's incomprehensible:

• "The tryCode() function is called in loop" - is this the function I'm supposed to implement or call myself?
• "then it is the result array of the confrontation between last proposition and solution" - this statement makes no sense whatsoever.
• "tryCode([1, 0, -1]) // [0, 2, 4] isn't the solution..." - why is there no output? And why is the JavaScript's single-line-comment syntax used in the middle of the text?

Swift version. I added return [] to the body and tried to run. The result was:

Assertion failed: file setup.swift, line 4

Looks like the test is broken.

Please fix errors related to 'XCTAssertEqual' and 'XCTFail'