add assert comments

list/list_test.go

@@ -24,7 +24,8 @@ func intListGen() *rapid.Generator[IList] {
 func TestConjIncreasesLength(t *testing.T) {
 	rapid.Check(t, func(t *rapid.T) {
 		myList := intListGen().Draw(t, "myList")
-		assert.Equal(t, myList.Len()+1, myList.Conj(42).Len())
+		newElem := rapid.Int().Draw(t, "newElem")
+		assert.Equal(t, myList.Len()+1, myList.Conj(newElem).Len(), "conj increases length")
 	})
 }
 
@@ -32,32 +33,34 @@ func TestRestDecreasesLength(t *testing.T) {
 	rapid.Check(t, func(t *rapid.T) {
 		myList := intListGen().Draw(t, "myList")
 		if myList.IsEmpty() {
-			assert.Equal(t, 0, myList.Rest().Len())
+			assert.Equal(t, myList.Len(), myList.Rest().Len(), "rest does not change length for empty list")
 		} else {
-			assert.Equal(t, myList.Len()-1, myList.Rest().Len())
+			assert.Equal(t, myList.Len()-1, myList.Rest().Len(), "rest decreases length of non-empty list")
 		}
 	})
 }
 
 func TestFirstIsNilOnlyWhenEmpty(t *testing.T) {
 	assert.Equal(t, 1, New(3).Conj(2).Conj(1).First())
+
 	rapid.Check(t, func(t *rapid.T) {
 		myList := intListGen().Draw(t, "myList")
-		assert.Equal(t, myList.IsEmpty(), myList.First() == nil)
+		assert.Equal(t, myList.IsEmpty(), myList.First() == nil, "first is nil only when list is empty")
 	})
 }
 
 func TestStringifyIntList(t *testing.T) {
 	assert.Equal(t, "(1 2 3)", New(3).Conj(2).Conj(1).String())
+
 	rapid.Check(t, func(t *rapid.T) {
 		myList := intListGen().Draw(t, "myList")
 		s := myList.String()
-		r := regexp.MustCompile(`\(.*\)`)
+		r := regexp.MustCompile(`^\([\d\s-]*\)$`)
-		assert.Equal(t, true, r.Match([]byte(s)))
+		assert.Equal(t, true, r.Match([]byte(s)), s + " looks like a string")
 		if !myList.IsEmpty() {
-			assert.Equal(t, myList.Len(), strings.Count(s, " ")+1)
+			assert.Equal(t, myList.Len(), strings.Count(s, " ")+1, "number of spaces in string should match count of elements")
 		} else {
-			assert.Equal(t, 0, strings.Count(s, " "))
+			assert.Equal(t, 0, strings.Count(s, " "), "no spaces in string for empty list")
 		}
 	})
 }