Binary Search Tree exercise in Swift: all tests passed but reported errors!

Exercism Support
1

It appears that although my code is working correctly warnings are preventing successful completion of tests. Here is the content of the results page:

AN ERROR OCCURRED
We received the following error when we ran your code:
/mnt/exercism-iteration/Tests/BinarySearchTreeTests/BinarySearchTreeTests.swift:11:13: warning: variable 'four' was never mutated; consider changing to 'let' constant
        var four = BinarySearchTree(4)
        ~~~ ^
        let
/mnt/exercism-iteration/Tests/BinarySearchTreeTests/BinarySearchTreeTests.swift:18:13: warning: variable 'four' was never mutated; consider changing to 'let' constant
        var four = BinarySearchTree(4)
        ~~~ ^
        let
/mnt/exercism-iteration/Tests/BinarySearchTreeTests/BinarySearchTreeTests.swift:25:13: warning: variable 'four' was never mutated; consider changing to 'let' constant
        var four = BinarySearchTree(4)
        ~~~ ^
        let
/mnt/exercism-iteration/Tests/BinarySearchTreeTests/BinarySearchTreeTests.swift:32:13: warning: variable 'four' was never mutated; consider changing to 'let' constant
        var four = BinarySearchTree(4)
        ~~~ ^
        let
/mnt/exercism-iteration/Tests/BinarySearchTreeTests/BinarySearchTreeTests.swift:53:13: warning: variable 'four' was never mutated; consider changing to 'let' constant
        var four = BinarySearchTree(4)
        ~~~ ^
        let
/mnt/exercism-iteration/Tests/BinarySearchTreeTests/BinarySearchTreeTests.swift:59:13: warning: variable 'four' was never mutated; consider changing to 'let' constant
        var four = BinarySearchTree(4)
        ~~~ ^
        let
/mnt/exercism-iteration/Tests/BinarySearchTreeTests/BinarySearchTreeTests.swift:65:13: warning: variable 'four' was never mutated; consider changing to 'let' constant
        var four = BinarySearchTree(4)
        ~~~ ^
        let
[8/12] Merging module BinarySearchTreeTests
[10/13] /tmp/86648C50-4FA2-4969-AAF6-C2D5FDE5C591/x86_64-unknown-linux-gnu/debug/BinarySearchTreePackageTests.derived/main.swift
[11/13] Wrapping AST for BinarySearchTreeTests for debugging
[12/15] Compiling BinarySearchTreePackageTests BinarySearchTreeTests.swift
[13/15] Compiling BinarySearchTreePackageTests main.swift
[15/17] Merging module BinarySearchTreePackageTests
[17/18] Wrapping AST for BinarySearchTreePackageTests for debugging
[18/18] Linking BinarySearchTreePackageTests.xctest
[18/18] Build complete!
Test Suite 'All tests' started at 2023-04-07 14:44:13.421
Test Suite 'debug.xctest' started at 2023-04-07 14:44:13.455
Test Suite 'BinarySearchTreeTests' started at 2023-04-07 14:44:13.455
Test Case 'BinarySearchTreeTests.testAllDataForComplexTree' started at 2023-04-07 14:44:13.455
Test Case 'BinarySearchTreeTests.testAllDataForComplexTree' passed (0.002 seconds)
Test Case 'BinarySearchTreeTests.testAllDataForLargerElement' started at 2023-04-07 14:44:13.457
Test Case 'BinarySearchTreeTests.testAllDataForLargerElement' passed (0.0 seconds)
Test Case 'BinarySearchTreeTests.testAllDataForOneElement' started at 2023-04-07 14:44:13.457
Test Case 'BinarySearchTreeTests.testAllDataForOneElement' passed (0.0 seconds)
Test Case 'BinarySearchTreeTests.testAllDataForSmallerElement' started at 2023-04-07 14:44:13.457
Test Case 'BinarySearchTreeTests.testAllDataForSmallerElement' passed (0.0 seconds)
Test Case 'BinarySearchTreeTests.testComplexTree' started at 2023-04-07 14:44:13.458
Test Case 'BinarySearchTreeTests.testComplexTree' passed (0.0 seconds)
Test Case 'BinarySearchTreeTests.testDataIsRetained' started at 2023-04-07 14:44:13.458
Test Case 'BinarySearchTreeTests.testDataIsRetained' passed (0.0 seconds)
Test Case 'BinarySearchTreeTests.testInsertingLess' started at 2023-04-07 14:44:13.458
Test Case 'BinarySearchTreeTests.testInsertingLess' passed (0.0 seconds)
Test Case 'BinarySearchTreeTests.testInsertingRight' started at 2023-04-07 14:44:13.458
Test Case 'BinarySearchTreeTests.testInsertingRight' passed (0.0 seconds)
Test Case 'BinarySearchTreeTests.testInsertingSame' started at 2023-04-07 14:44:13.458
Test Case 'BinarySearchTreeTests.testInsertingSame' passed (0.0 seconds)
Test Suite 'BinarySearchTreeTests' passed at 2023-04-07 14:44:13.458
	 Executed 9 tests, with 0 failures (0 unexpected) in 0.003 (0.003) seconds
Test Suite 'debug.xctest' passed at 2023-04-07 14:44:13.458
	 Executed 9 tests, with 0 failures (0 unexpected) in 0.003 (0.003) seconds
Test Suite 'All tests' passed at 2023-04-07 14:44:13.458
	 Executed 9 tests, with 0 failures (0 unexpected) in 0.003 (0.003) seconds

Can’t submit because of this!!

2

Have you tried changing var to let?

3

It’s the test code that’s causing the problem!! I don’t think I can change that.

4

Ooh! I missed that. That does sound like a Swift issue :slight_smile:
Let’s give this post some time for a Swift maintainer (or even someone that knows Swift better than me!) to chime in and see what they say.