More helpful error message when instantiating an abstract class #9474
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can you write two test cases to verify that AR::Base cant be instantiated and that an abstract class can't be instantiated? Also we would need a CHANGELOG entry explaining the change. |
| @@ -1,5 +1,9 @@ | |||
| ## Rails 4.0.0 (unreleased) ## | |||
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| * Throw NotImplementedError when trying to instantiate Base or an abstract class. | |||
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just a nitpick but it would be nice to put the constant name inside .
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added a few minor comments. |
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Thanks, comments addressed in HonoreDB@f128e79. |
| def test_initialize_abstract_class | ||
| assert_raises(NotImplementedError) do | ||
| FirstAbstractClass.new | ||
| end |
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you should assign the exception to check the message:
e = assert_raises(XX) {}
assert_equals "<expected>", e.message
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the PR does no longer cleanly apply to master. Can you push a rebased version? |
Calling a literal ActiveRecord::Base.new raises NoMethodError, since it ends up calling Class.abstract_class? which does not exist. Similarly, instantiating an actual abstract class hits the database, when conventionally it should immediately throw NotImplementedError. ActiveRecord::Base can't be made abstract without breaking many, many things, so check for it separately.
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Rebased, tests now check the error message in addition to the type. |
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@HonoreDB amazing! thanks for the fast update. 💛 @carlosantoniodasilva @rafaelfranca can you take a final look? |
rafaelfranca
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Mar 7, 2013
More helpful error message when instantiating an abstract class Conflicts: activerecord/CHANGELOG.md
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Calling a literal
ActiveRecord::Base.newraisesNoMethodError,since it ends up calling
Class.abstract_class?which does not exist.Similarly, instantiating an actual abstract class hits the database,
when conventionally it should immediately throw
NotImplementedError.ActiveRecord::Basecan't be made abstract without breaking many,many things, so check for it separately.