Problem
You are trying to install the gems for your rails application in a new computer, or by using ruby 2.4 and you get the following error:
An error occurred while installing json (1.8.3), and Bundler cannot continue. Make sure that `gem install json -v '1.8.3'` succeeds before bundling.
Solution
Remove your old Gemfile.lock file and run bundle again. A newer version of json (ie 1.8.6) should be installed.
Problem
You have a Ruby on Rails application/engine with some tests in Minitest and using postgresql as the db. In the original development environment all the tests that use fixtures and foreign key validations pass, but when you try to move to a different environment with new database some or all of you tests fail with a message that refers to the ForeignKeyViolation as in:
ActiveRecord::InvalidForeignKey: PG::ForeignKeyViolation: ERROR: insert or update on table "tbl_name" violates foreign key constraint "tbl_name_cln_name_fk_tbl_name_fk" DETAIL: Key (col_name)=(VALUE) is not present in table "fk_tbl_name".
Solution
Since active record disables the foreign keys before loading the fixtures in the database, the user that you run the tests with needs to have superuser permissions in the test database. Otherwise the fixtures are not loaded. So add the superuser permissions to your user:
psql -U super_user alter role use_for_tests superuser;
You may need to drop and create your test database.
Problem
You are working on an existing rails project with many rubocop warnings and you would like to fix certain types or warnings by getting only the specified files.
Solution
So for example when you use rubocop you first get the following for all the files in the project:
rubocop 799 files inspected, 17214 offenses detected
You can get a grouping of the errors by using the following:
rubocop --format offenses 7176 Style/StringLiterals 3596 Metrics/LineLength 1031 Style/VariableName 790 Style/IndentationConsistency 548 Style/SpaceAroundOperators 423 Style/Documentation 415 Style/HashSyntax 386 Style/TrailingWhiteSpace 198 Style/SpaceAfterComma ...
If you would like to know only the files for a certain type of warning to be able to fix them you could try the following:
rubocop --only Style/TrailingWhitespace ..... list of files 799 files inspected, 386 offenses detected
Problem
You want to use some array method in a value returned, which can either be a single value or an array of values.
Solution
Rails ActiveSupport Array, provides a method called wrap, that can be used to:
Wraps its argument in an array unless it is already an array (or array-like)
Full explanation of the method here.
Thanks Miles
Problem
You want to install rbenv, but when you are trying to clone the code with:
git clone https://github.com/rbenv/rbenv.git ~/.rbenv
you get the following error:
fatal: unable to access 'https://github.com/rbenv/rbenv.git/': SSL received a record that exceeded the maximum permissible length.
Solution
If you are behind a proxy server make sure that you add your proxy server details in your ~/.bash_profile and source the file afterwards.
So first add the details of your proxy like:
export http_proxy=http://xxx.xxx.xxx.xxx:8080 export https_proxy=https://xxx.xxx.xxx.xxx:8080
And finally source the file before running the installation again:
source ~/.bash_profile
Trying to deploy a rails application in a cloud provider ie dreamhost, that uses OpenStack these are the steps needed:
sudo docker pull rails:latest
rails new docker_test
FROM rails:onbuild
sudo docker build -t rails_docker_test .
sudo docker images
sudo docker run --name rails_test -p 0.0.0.0:3000:3000 -d rails_docker_test
sudo docker login --username=yourhubusername --email=youremail@company.com
, and then when you get ‘Login Succeeded’, push your image to your account:
sudo docker push yourhubusername/rails_docker_test
Problem
You are trying to upgrade one of your gems (ie uglifier) and at the same time you are using a new gemset (ie for rails 4.2.4), and you get the following error when you are trying to bundle:
Could not find libv8-3.16.14.9 in any of the sources
Solution
Upgrade to rails 4.2.4 first and bundle and afterwards change the other gem and do bundle again.
Problem
When you are adding new attributes to your model after the initial creation, they are not by default included in the permitted parameters list. Sometimes the error is not so obvious to see when testing, unless you look at the test log files.
Solution
To make the error more obvious, there is the following configuration option that you can set up in config/environments/test.rb (tip taken from Rails 4 In Action):
config.action_controller.action_on_unpermitted_parameters = :raise
Problem
When trying to use the minitest assert_routing with the first parameter representing the path as a hash that includes both the path and the method, and run the tests rails complains about SyntaxErrors.
When trying to use it as suggested in the ‘Rails 4 Test Prescriptions’ Pragmatic Programmers book (p. 172 – Minitest and Routing) which is:
assert_routing({ path: "/projects", method: "post" },
controller: "projects", action: "create")
the error is:
SyntaxError: /.../test/controllers/projects_controller_test.rb:12: syntax error, unexpected ',', expecting ')' ... '/projects', method: 'post' }, controller: 'projects', act...
even when trying to have the second parameter as a hash:
assert_routing({ path: "/projects", method: "post" },
{ controller: "projects", action: "create" })
the error is similar:
SyntaxError:
/.../test/controllers/projects_controller_test.rb:12:
syntax error, unexpected ',', expecting ')'
... '/projects', method: 'post' },
{ controller: 'projects', ac...
Solution
Seems that you need to pass the parameters enclosed in brackets, so the following would work:
assert_routing ({ path: '/projects', method: 'post' }),
({ controller: 'projects', action: 'create' })
Problem
You are getting the error:
bin/rails:6: warning: already initialized constant APP_PATH
when you are trying to start the local webserver with rails s.
Solution
That happens when are using the bootstrap rails gem as in:
gem 'anjlab-bootstrap-rails', require: 'bootstrap_rails'
It is important that the bootstap rails uses in the require is used with a dash and NOT an underscore.
So when you write the the gem as follows:
gem 'anjlab-bootstrap-rails', require: 'bootstrap-rails'
and restart your server you should no longer have the error message.