Refactor existing unit tests

shared/src/androidUnitTest/kotlin/org/tle/astrologylibrary/Test.android.kt

@@ -1,12 +1,13 @@
 package org.tle.astrologylibrary
 
-import org.junit.Assert.assertTrue
+import assertk.assertThat
+import assertk.assertions.contains
 import org.junit.Test
 
 class AndroidGreetingTest {
 
     @Test
     fun testExample() {
-        assertTrue("Check Android is mentioned", Greeting().greet().contains("Android"))
+        assertThat(Greeting().greet()).contains("Android")
     }
 }

shared/src/commonTest/kotlin/org/tle/astrologylibrary/SubjectTest.kt

@@ -1,8 +1,9 @@
 package org.tle.astrologylibrary
 
+import assertk.assertThat
+import assertk.assertions.isEqualTo
 import dev.mokkery.mock
 import kotlin.test.Test
-import kotlin.test.assertEquals
 
 class SubjectTest {
     @Test
@@ -10,7 +11,7 @@ class SubjectTest {
         val a = mock<A> {}
         val b = mock<B> {}
         val subject = Subject(a, b)
-        assertEquals(a, subject.a)
-        assertEquals(b, subject.b)
+        assertThat(subject.a).isEqualTo(a)
+        assertThat(subject.b).isEqualTo(b)
     }
 }

shared/src/commonTest/kotlin/org/tle/astrologylibrary/Test.kt

@@ -1,12 +1,13 @@
 package org.tle.astrologylibrary
 
+import assertk.assertThat
+import assertk.assertions.contains
 import kotlin.test.Test
-import kotlin.test.assertTrue
 
 class CommonGreetingTest {
 
     @Test
     fun testExample() {
-        assertTrue(Greeting().greet().contains("Hello"), "Check 'Hello' is mentioned")
+        assertThat(Greeting().greet()).contains("Hello")
     }
 }