chrisma / i22 Goto Github PK

Scenario

When creating a paper without venue
Then validation should fail

Hints

Papers should not be valid without having all attributes (title, venue and year) set. Year should be a numeric value.

Validation reference

Error

Expected #<paper id: nil, title: "computing machinery and intelligence", venue: nil, year: 1950, created_at: nil, updated_at: nil> not to be valid

24 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

Given a paper
When a user visits the paper's edit page
Then it should have a single multiple select box

Hints

Make sure the n:m relation of papers and authors works in your automated tests, i.e. models are annotated with has_and_belongs_to_many and a db migration for the new join table was created and run.

On a paper's edit page, it should be possible to add multiple authors.
An HTML multiple select element allows this.
Rails' select helper in combination with the 'options_from_collection_for_select' helper can be used to create the required HTML element:

<%= form.select 'author_ids',
  options_from_collection_for_select(Author.all, :id, :name, paper.author_ids),
  {},
  multiple: true, size: 10 %>

Notice the usage of author_ids in the code snippet. These are the ids transmitted by the form to the server.

The paper controller must be able to deal with the additional author information that is passed by the new select element to save the changes.
Make sure that you have "permitted" the parameters for passing the author ids to the paper controller (function paper_params) using :author_ids => [].

Error

Expected to find css "select[multiple]" 1 time but there were no matches

40 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

When a user visits the new author page
Then it should have a text input field with the name 'author[first_name]'

Hints

The "new author" page (at /authors/new) is empty. Before adding input fields, create a test that checks for their presence.

In the spec file (spec/features/author/new_author_spec.rb), create a new it block with a descriptive name. Inside the block, after visiting the "new author" page, the test should check for input fields.

RSpec uses matchers to check if a given object is present or valid. For example have_field checks if the HTML of the page contains an input form field with the given label, name or id. For more matchers, see this Cheat Sheet or the documentation.

The following code snippet shows what your test could look like. You can copy&paste this code, but understand what every instruction does before moving on.

it "should have text inputs for an author's first name, last name, and homepage" do
  visit new_author_path
  # these are the standard names given to inputs by the Rails form builder
  expect(page).to have_field('author[first_name]')
  expect(page).to have_field('author[last_name]')
  expect(page).to have_field('author[homepage]')
end

After committing the test, add the form fields for first_name, last_name and homepage. It should look something like this. To create a form within the views/authors/new.html.erb view, you can use a form builder, which generates the required HTML.
The primary form builder for Rails is provided by a helper method called form_with. See the Rails Guide.

Don't worry if submitting the form causes an error at this point, that functionality will follow.

Error

Expected to find field "author[first_name]" that is not disabled but there were no matches

2 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

Given an author named 'Alan Turing'
When a user visits Turing's details page
Then no error should occour

Hints

A 'show' page displays an author's details.
In a test, visit the show page of @alan with visit author_path(@alan).

Create a separate file for author show page feature tests. Make sure it ends with _spec.rb, so that RSpec recognizes it as a test and runs it.
Test for existence of text on a page using the have_text matcher:
expect(page).to have_text(...).

Create a show action on the AuthorsController and a 'show' view (app/views/authors/show.html.erb).
Here is the relevant section (5.7) of the Rails Guide.

Tip: FactoryBot.create :author creates and saves a valid author object in your tests. If you un-comment the code in spec/factories/authors.rb, the author will be initialized with meaningful values.

Error

Got AbstractController::ActionNotFound: The action 'show' could not be found for AuthorsController

7 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

Given an author named 'Alan Turing'
When a user visits the edit page of the author Alan Turing
Then no error should occour

Hints

Feature: Changes made to the authors in an edit form (similar to the 'new' form) should be written to the database.

New controller actions (edit and update) and a new view are required.
Tests could be placed in spec/features/author/edit_author_spec.rb.
In a test, if an object's values should be reloaded from the database, after an action has modified them, consider the reload method:
@author.reload

Here is the relevant section (5.11) of the Rails Guide.

Error

Got AbstractController::ActionNotFound: The action 'edit' could not be found for AuthorsController

16 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

Given an eager student
When they have completed the Ruby on Rails exercise
Then they should celebrate!

Thanks for taking part in the exercise! We would appreciate your feedback to continue to improve in the future.

Please fill out this survey to help the teaching team improve this exercise

Error

Got Students: 'Done!'

43 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

Given a paper
When users visit the papers index page
Then it should show a a delete link for every paper

Error

Expected to find css "a[data-turbo-method='delete'][href='/papers/1']" but there were no matches

36 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

When a user visits the new paper page
Then the page should render

Hints

A paper management system manages papers in addition to authors.
Papers should have a 'title' and a 'venue' string as well as a 'year' integer, indicating publishing date.
Papers should be manageable by users using views similar to authors.

Instead of generating the paper model and all the needed controllers and views separately (for new, create, read, update, etc.), use a Rails scaffold.
It generates a model, a database migration, controller and views, and a basic suite:
rails generate scaffold paper title:string venue:string year:integer
Take a look at the generated files and adapt the tests.

The new migrations need to be applied: rails db:migrate RAILS_ENV=development && rails db:migrate RAILS_ENV=test

Error

Got NameError: undefined local variable or method `new_paper_path' for #RSpec::ExampleGroups::NewPaperPage:0x00007fe8509fe7d8
Did you mean? new_author_path

19 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

When creating a paper without year
Then validation should fail

Hints

Papers should not be valid without having all attributes (title, venue and year) set. Year should be a numeric value.

Validation reference

Error

Expected #<paper id: nil, title: "computing machinery and intelligence", venue: "mind 49: 433-460", year: nil, created_at: nil, updated_at: nil> not to be valid

26 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

Given a paper
When users visit the papers index page
Then it should link to the paper's edit page

Error

Expected to find link nil with href "/papers/1/edit" but there were no matches

35 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

Given a paper with one author
And another author called 'Peter Plagiarist'
When a user visits the paper's edit page
And then selects 'Peter Plagiarist' as author
And submits the form
Then 'Peter Plagiarist' and 'Alan Turing' should be authors of the paper

Hints

The paper controller must be able to deal with the additional author information that is passed by the new select element to save the changes.
Make sure that you have "permitted" the parameters for passing the author ids to the paper controller (function paper_params) using :author_ids => [].

Error

Expected collection contained: [#<author id: 1, first_name: "alan", last_name: "turing", homepage: "http://wikipedia.de/alan_turing"...eated_at: "2022-10-28 10:58:07.166196000 +0000", updated_at: "2022-10-28 10:58:07.166196000 +0000">]
actual collection contained: [#<author id: 1, first_name: "alan", last_name: "turing", homepage: "http://wikipedia.de/alan_turing"...eated_at: "2022-10-28 10:58:07.164877000 +0000", updated_at: "2022-10-28 10:58:07.164877000 +0000">]
the missing elements were: [#<author id: 2, first_name: "peter", last_name: "plagiarist", homepage: "http://wikipedia.de/alan_tu...eated_at: "2022-10-28 10:58:07.166196000 +0000", updated_at: "2022-10-28 10:58:07.166196000 +0000">]

41 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

When a user visits the authors index page
Then the page should render

Hints

Feature: an overview page of all saved authors (index action on AuthorsController), new view (app/views/authors/index.html.erb).

Create a separate file (ending in _spec.rb) for feature tests for this page.
The overview page should contain an HTML table with the headings "Name" and "Homepage", listing the full names as well as homepages of authors and should link to individual author's detail pages. The page should also contain a link to add new authors.
The have_link method might be helpful to test the existence of links:
expect(page).to have_link 'New', href: new_author_path

Here is the relevant section (5.8) of the Rails Guide.

Error

Got AbstractController::ActionNotFound: The action 'index' could not be found for AuthorsController

8 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

When creating a paper with year 'nineteen-fifty'
Then validation should fail

Hints

Papers should not be valid without having all attributes (title, venue and year) set. Year should be a numeric value.

Validation reference

Error

Expected #<paper id: nil, title: "computing machinery and intelligence", venue: "mind 49: 433-460", year: 0, created_at: nil, updated_at: nil> not to be valid

27 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

Given a paper
Then it should have an empty list of authors

Hints

A paper can have many authors and an author can write many papers.
This relationship is indicated in Rails by annotating both models (i.e. the Author and Paper) with a has_and_belongs_to_many association.

To store this n:m relation, create a new database table in a migration: guide.
There is a generator which can produce join tables if 'JoinTable' is part of the name:

rails generate migration CreateJoinTableAuthorPaper author paper

To test if such a relation exists, you can test whether a paper has an empty list of authors.

Reminder: Migrations are stored in db/migrate and are applied with the rails db:migrate command.

Error

Got NoMethodError: undefined method `authors' for #Paper:0x0000562168a73840

37 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

Given a paper with an author
When a user visits the paper's show page
Then it should show the author's full name

Error

Expected to find text "alan turing" in "title: computing machinery and intelligence\nvenue: mind 49: 433-460\nyear: 1950\nedit this paper | back to papers | delete this paper"

39 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

When creating an author without last name
Then validation should fail

Hints

Author data should pass checks, i.e. validations in Ruby on Rails, before being saved.
In particular, an author's last name should not be an empty string.

In your test for this behavior, be_valid can be used to test if a model instance passes validations:
expect(@author).to_not be_valid

Here is the relevant section (5.10) of the Rails Guide.

Error

Expected #<author id: nil, first_name: "alan", last_name: nil, homepage: "http://example.com", created_at: nil, updated_at: nil> not to be valid

13 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

When an author is created with first name 'Alan', last name 'Turing', and homepage 'http://wikipedia.org/Alan_Turing'
Then an instance of Author should be created

Hints

The author model should have a first_name, last_name and homepage, which are all strings.
It should furthermore have a method name (no parameters) which returns the full name of an author (the first name followed by the last name), e.g. 'Alan Turing'.

Test this model behavior in a model test. Create spec/models/author_spec.rb and in the describe block, specify type: :model.
In a model test, behavior is tested directly on the model object, e.g.

author = Author.new(...)
expect(author.first_name).to eq(...)

The eq matcher tests for object equivalence.
See this reference for more matchers.

To pass your test a Rails model for authors must be created. Rails has generators which make creating things easier. You can answer 'no' when Rails asks if you want to overwrite files, then your edited files stay the way they are.
Here is the relevant section (5.4) of the Rails Guide. The generator creates the required model attributes (e.g. first_name:string, see db/schema.rb for the changes) and maps them to the corresponding model. You can then use the attributes as variables in the model (i.e. author.first_name).

Additional model methods are specified in the model's file, e.g. app/models/author.rb using standard Ruby syntax.

Error

Got NameError: uninitialized constant Author

4 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

Given an author named 'Alan Turing'
When users visit the authors index page
Then it should have a link to the individual author's edit page

Hints

The table on the author overview page should include additional links to the edit form of each listed author.
Adapt index_author_spec.rb and the author index view.

Error

Expected to find link nil with href "/authors/1/edit" but there were no matches

17 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

Given a paper published in 1950
And a paper published in 1968
When users visit the papers index page with url parameter year=1950
Then it should not show the paper published in 1968

Hints

Almost done with the exercise!

A long list of papers can be hard to search. Allow filtering the list of papers on the paper index page (by year) with an URL parameter, e.g. http://localhost:3000/papers?year=1970.
You can use scopes to implement this behavior in the Paper model and adapt the PapersController's index action to take params[:year] into account.
Consider the subheadings Passing in arguments and using conditionals of the Rails Guide.

Error

Expected not to find text "go to statement considered harmful" in "papers\ntitle: computing machinery and intelligence\nvenue: mind 49: 433-460\nyear: 1950\nauthors:\nshow | edit | delete\ntitle: go to statement considered harmful\nvenue: communications of the acm\nyear: 1968\nauthors:\nshow | edit | delete\nnew paper"

42 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

When a user visits the new author page
Then the page should be available at the new_author_path route and should render without errors

Hints

Currently, the application contains a single route (at /, see config/routes.rb), a view (app/views/home/index.html.erb) and a controller (app/controllers/home_controller.rb), connecting them.
All available application routes are displayed using the command rails routes.

Before implementing the requested feature, write a test for it. The file spec/features/author/new_author_spec.rb contains the needed test case, it needs to be un-commented.

The describe block defines which aspect will be tested. Specifying the feature type includes helper methods for simulating browser actions in tests. Each it block is a single test case. The test tries to access the path (i.e. the URL) of the "new author" page. This fails because no such path is defined yet.

Run the test (bundle exec rspec) and commit the failing test case.

To make the test pass, see the Rails Guide for creating the appropriate controllers, views and setting up routes for authors. Note: Instead of articles (in the guide), this exercise is concerned with authors.

You can learn more about RSpec, the testing framework here.

Error

Got NameError: undefined local variable or method `new_author_path' for #RSpec::ExampleGroups::NewAuthorPage:0x00007f90742d4040
Did you mean? new_polymorphic_path

1 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

Given an author named 'Alan Turing'
When users visit the authors index page
Then it should have link to delete an author

Hints

To delete a record following the REST paradigm, a DELETE request needs to be made.
As not many browsers support this directly, the DELETE call is made using JavaScript.
Newer versions of Rails support this using the turbo dependency.
Install it using rails importmap:install turbo:install stimulus:install (answer 'y' to overwrite existing files).

The following data attributes (read by JS) turn the usual GET request of a link into a DELETE (with confirmation messge):
<%= link_to 'Delete', author_path(author), data: {turbo_method: :delete, turbo_confirm: "Are you sure?"} %>

After an author is deleted Author.count should have decreased.

A destroy controller action is needed.
Here is the relevant section (5.13) of the Rails Guide. (Please be aware that the link_to syntax of the guide is outdated, see code above.)

Error

Expected to find css "a[data-turbo-method='delete'][href='/authors/1']" but there were no matches

18 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

When a user visits the new author page
And fills in 'Alan', 'Turing', and 'http://wikipedia.org/Alan_Turing', respectively
And submits the form
Then Alan Turing should be found in the database

Hints

Write a test that visits the new-author page, fills in the 'new author' form and submits it.
Use fill_in to enter data into input fields.
Submit the form using the find and click methods.
Try a new it block in new_author_spec.rb.

visit new_author_path
page.fill_in 'author[last_name]', with: 'Dijkstra'
# ...
find('input[type="submit"]').click

Here is the relevant section (5.6) in the Rails Guide.

Make the failing test pass by saving the POSTed form data in a new Author database object.
This is the task of a create action in authors_controller.rb.
Make sure to set the :url option of the form_with, to control where the data will be POSTed to. Read up on "strong parameters" and whitelisting of required parameters.

Do not issue a redirect_to @author, as this will error (there is no code for showing authors yet). Instead you can redirect_to root_path, notice: 'Success!'.

Tips:

• Your browser's dev tools are helpful in debugging and inspecting HTML.
• rails console allows you to interact with stored object in an interactive shell, e.g. Author.count shows the amount of stored authors.

Error

Got ActiveRecord::RecordNotFound: Couldn't find Author with [WHERE "authors"."last_name" = ?]

6 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

Given users visit the new author page
And fills in only first name and homepage, and NOT the last name
When they click submit
Then the page should 'error' and what went wrong

Hints

Validation errors should be communicated to the user.

These are stored in the errors attribute of model instances.
It can be checked (@author.errors.any?) and can be iterated over to extract error details (@author.errors.full_messages.each).
Adding this type of code also requires modifying the new action of the AuthorsController.

Your test can try to create an invalid object (on the new author page) and check whether 'error' is displayed.

Here is the relevant section (5.10) of the Rails Guide.

Error

Expected to find text matching /error/i in "success!\npaper management system\nyou are seeing the rendered view of 'views/home/index.html.erb'"

15 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.

Scenario

When creating a paper without title
Then validation should fail

Hints

Papers should not be valid without having all attributes (title, venue and year) set. Year should be a numeric value.

Validation reference

Error

Expected #<paper id: nil, title: nil, venue: "mind 49: 433-460", year: 1950, created_at: nil, updated_at: nil> not to be valid

22 exercise tests have passed. There are 44 in total. You will solve multiple at once towards the end.