add minor notes

Author: Xronophobe

chapter_13_database_layer_validation.asciidoc

@@ -56,6 +56,10 @@ selenium.common.exceptions.NoSuchElementException: Message: Unable to locate
 element: .invalid-feedback; For documentation [...]
 ----
 
+// CSANAD: I don't have the "For documentation" here:
+//   Unable to locate element: .invalid-feedback
+// I only have the stack trace.
+
 It's expecting to see an error message if the user tries to input an empty
 item.
 
@@ -131,6 +135,8 @@ except ValidationError:
 
 But the `with` formulation is neater.  Now, we can try running the test,
 and see its expected failure:
+// CSANAD: I would highlight we are running the unit test here
+// python src/manage.py test lists
 
 ----
     with self.assertRaises(ValidationError):
@@ -155,6 +161,7 @@ So why is the test still failing?
 Well, for
 http://bit.ly/2v3SfRq[slightly counterintuitive historical reasons],
 Django models don't run full validation on save.
+// CSANAD: I'd argue against the use of shortened URLs.
 As we'll see later,
 any constraints that are actually implemented in the database
 will raise errors on save,
@@ -167,6 +174,9 @@ But Django knows that SQLite doesn't support this type of constraint,
 so if we try to run `makemigrations`, it will report there's nothing to do:
 
 
+// CSANAD: maybe I'm missing something here but I don't think there would have
+//         been any changes detected here even with another DB. I don't remember
+// changing the model since the last migration.
 [subs="specialcharacters,macros"]
 ----
 $ pass:quotes[*python src/manage.py makemigrations*]
@@ -538,7 +548,9 @@ element: .invalid-feedback; [...]
 ----
 
 
-Not quite, but they did get a little further.  Checking 'line 31', we can
+Not quite, but they did get a little further.  Checking the line in which the
+error occurred -- 'line 31' in my case -- , we can
+// CSANAD: I think emphasizing what to look for in the error log is helpful.
 see that we've got past the first part of the test, and are now onto the second
 check--that submitting a second empty item also shows an error.