Does Kotest have the equivalent of AssertJ s `extracting` fe

Question

Does Kotest have the equivalent of AssertJ s `extracting` feature For example in AssertJ I can do this ```assertThat foo extracting Foo id Foo description containsExactly 1234 this is a foo ``` The closest I could find was `shouldBeEqualUsingFields` but that s not suitable as it requires another Foo argument which I can t easily construct I only have the naked property values

Jim · Answer

I d do ```all foo it id shouldBe 1234 it description shouldBe stuff ```

LeoColman · Answer

I d go with ```assertSoftly foo it id shouldBe 1234 it description shouldBe stuff ```

LeoColman · Answer

This way you d get every failing assertion

Jim · Answer

Yeah all ~= assertSoftly

Emil Kantis · Answer

Agree but you don t need to use `it` iirc the assertSoftly should lambda should already be scoped to the subject

Jim · Answer

Yeah I couldn t remember if all was `T gt Unit` or ` T gt Unit` zany face

Jim · Answer

It might even be `T T ` I ve seen that here and there

Emil Kantis · Answer

Funny yeah it seems to be

Emil Kantis · Answer

``` test hello val p = Point 0 0 3 0 assertSoftly p x shouldBeGreaterThan 1 0 it y shouldBe 3 0 ```

Jim · Answer

I like both since you have access to the lambda arg you can destructure a pair or something with a useful name

sam · Answer

T T gt is a bizarre signature lol

Emil Kantis · Answer

good point < Jim> slightly smiling face

Klitos Kyriacou · Answer

Yes you can do that but then the assertion failure message is something like expecting 123 to be 456 The advantage of AssertJ s `extracting` method is that it tells you expecting id to be 456 but was 123 Much clearer and much more helpful

Jim · Answer

Maybe a reflection powered assertion could get us there with an auto clue

LeoColman · Answer

gt T T gt is a bizarre signature lol I want T both as a receiver and as a parameter The only way to do it really is crying before hence the T T

Emil Kantis · Answer

```assertProperties p Point x shouldBe 0 0 Point y shouldBe 3 0 ``` doable < Jim> slightly smiling face

Jim · Answer

I think I did something like this at work let me see

sam · Answer

We should add a compiler plugin that is better with shouldBe

sam · Answer

so `x shouldBe y` can capture the variable name on the left

sam · Answer

There s power assert which is cool because it builds a tree of the intermediate values but I think we could get half way there with something quicker that just captures the variable names which is mostly what I want to see

Jim · Answer

```fun isOdd x Int = x 2 = 0 data class IntWrapper val value Int fun isOddWrapper = isOdd value class SampleTests FunSpec test function pointer all IntWrapper 1 its isOddWrapper shouldBe false its isOdd shouldBe false data class ShouldBeLeft lt R gt val name String val actual R infix fun shouldBe expected R withClue Expected property $name to equal $expected but was $actual actual shouldBe expected infix fun lt T R gt T its kfunc T gt KFunction lt R gt ShouldBeLeft lt R gt val f = kfunc this return if f as FunctionReferenceImpl boundReceiver = null ShouldBeLeft f name f call else ShouldBeLeft f name f call this ```

Jim · Answer

damn too slow joy

Jim · Answer

```Expected property isOddWrapper to equal false but was true java lang AssertionError Expected property isOddWrapper to equal false but was true expected lt false gt but was lt true gt ```

Jim · Answer

only works with JVM I think though