Verify that route constraints respond to the expected messages instead of silently failing to enforce the constraint
Fix bugs with changed attributes tracking when transaction gets rollback
Fix Hash#deep_merge bug and improve documentation — resolves #12738

Previously merging into a hash with a falsy value would not result in
the merge-block being called. The fix is simply to check for presence
of the key in the hash.

The documentation example for `deep_merge` now appropriately
demonstrates what a deep merge does.
Fixed custom validation context bug where child
associations were not being saved.

Fixes #13854.

[Eric Chahin, Aaron Nelson, & Kevin Casey]
Fix exception when logging SQL w/ nil binary value.
make `db:structure:load` listed with `rake -T`
Move dup destroyed test to specific file that tests dup logic

Also change other related test to use existing record rather than
creating new one.
Add branch to arel on Gemfile to allow local bundle config [ci skip]
Add missing require to fix test :bomb:
Use #include? instead of #any?, make it simpler
Test typecasting on instance rather than class itself
Merge pull request #14957 from akshay-vishnoi/test-cases

Test typecasting on instance rather than class itself
[Fixes #14948] Hash#to_query: Changed a way how empty hash and empty array are serialized

Empty Hash or Array should not present in serialization result

    {a: []}.to_query # => ""
    {a: {}}.to_query # => ""

For more info see #14948.
Typo, grammar and textual changes [ci skip]
Merge pull request #14956 from akshay-vishnoi/refactor

Use #include? instead of #any?, make it simpler
Merge pull request #14924 from eric-chahin/issue_13854

Fixed custom validation context bug for child associations
docs, restructure newly added part to `includes`. [ci skip]

This is a follow up to #14139.

/cc @carlosantoniodasilva
Merge pull request #14952 from gregmolnar/schema_load

make `db:structure:load` listed with `rake -T`
Refactor test to not care about the specific result of valid?

Only care about its truthiness rather than asserting specific true/false
values. If we need to check for the return value in particular, there will
be a test for that.
Remove duplicated fixture addition