Rspec - Using variable defined in a let statement in another let statement - ruby

In my RSpec test, I have defined multiple methods using let() syntax. I have encountered a scenario where I need to use variable defined inside a let statement into another let statement inside same describe block.
context 'Reuse the name of first car in the second car' do
it_behaves_like 'some car test' do
let(:car1) do {
name1: "#{testcase['Car']}_#{Time.now.round}",
car_model: testcase['Toyota']
}
end
let(:car2) do {
name2: name1
}
end
end
end
As you can see I want to use the exact name value I defined name1 inside :car1 for name2 inside :car2. The above syntax throws me following error
NameError:
undefined local variable or method `name1' for #<RSpec::
How do I use exact value of name1 in :car2? Any ideas..

let(:name1) { "#{testcase['Car']}_#{Time.now.round}" }
let(:car1) { { name1: name1, car_model: testcase['Toyota'] } }
let(:car2) { { name2: name1 } }
So name1 is also now a lazy variable to initialized when is called, if not for car1, then for car2.
If the Time.now is a problem, you can leave the value of name1 as testcase['Car'] and then just interpolate the value of Time.now.

name1 is a key in the hash defined as car1, therefore you need to use the hash syntax to get its value:
let(:car1) do
{
name1: "#{testcase['Car']}_#{Time.now.round}",
car_model: testcase['Toyota']
}
end
let(:car2) do
{
name2: car[:name1]
}
end
Please note that this only answers your question on how to extract the value, I do not suggest writing specs like that. If both cars should share the same name than Sebastian's answer is probably clearer and easier to understand.

let definitions work just fine with each other.
You defined two things: car1 and car2.
Code is throwing an error about name1. You just didnt define it.
I guess you need to read more about ruby Hash and Symbol.

Related

How to make Ruby Mocha mock only check about one parameter

I want to mock this function:
def self.set_segment_info(segment_info, history_record)
history_record.segment_info = segment_info
end
In my test, I want a mock that only confirms that I called set_segment_info with an expected value. I don't care about what I pass in for history_record.
How would I do this? I tried
SegmentHistoryRecord.expects(:set_segment_info).with(:segment_info => expected_segment_info, :history_record => anything)
But that doesn't work.
I ran into this today and ended up doing something like:
SegmentHistoryRecord.expects(:set_segment_info).with(
expected_segment_info,
anything
)
I find it more readable that the do version and it helped me avoid a rubocop issue with too many parameters.
Here's an implementation where, if your function takes a lot of parameters, it's more convenient to specify a value for just the one you care about, instead of for all of them:
expected_segment_info = # ...
SegmentHistoryRecord.expects(:set_segment_info).with() { |actual_parameters| actual_parameters[:segment_info] == expected_segment_info }
(Where, as in the original question, set_segment_info is the function being mocked, and segment_info is the parameter whose value you want to match. Note that the history_record parameter -- and any others that might be present -- don't need to be included.)
SegmentHistoryRecord.expects(:set_segment_info).with() do |param1, param2|
# change below to your verification for :segment_info
# and leave param2 doing nothing, the expectation will ignore param2
param1 == expected_segment_info
end

How to use polymorphism to remove a switch statement which compares strings?

I am new to Ruby, so let me describe the context of my problem first:
I have a json as input which has the following key / value pair:
{
"service": "update"
}
The value has many different values for example: insert,delete etc.
Next there is a method x which handles the different requests:
def x(input)
case input[:service]
services = GenericService.new
when "update"
result = services.service(UpdateService.new,input)
when "insert"
result = services.service(InsertService.new,input)
when "delete"
result = services.service(DeleteService.new,input)
....
....
else
raise "Unknown service"
end
puts JSON.pretty_generate(result)
end
What is bothering me is that I still need to use a switch statement to check the String values (reminds me of 'instance of' ugh..). Is there a cleaner way (not need to use a switch)?
Finally I tried to search for an answer to my question and did not succeed, if however I missed it feel free to comment the related question.
Update: I was thinking to maybe cast the string to the related class name as follows: How do I create a class instance from a string name in ruby? and then call result = services.services(x.constantize.new,input) , then the class names ofcourse needs to match the input of the json.
You can try something like:
def x(input)
service_class_name = "#{input[:service].capitalize}Service"
service_class = Kernel.const_get(service_class_name)
service_class.new(input).process
end
In addition you might want to check if this is a valid Service class name at all.
I don't understand why you want to pass the service to GenericService this seems strange. let the service do it's job.
If you're trying to instatiate a class by it's name you're actually speaking about Reflection rather than Polymorphism.
In Ruby you can achieve this in this way:
byName = Object.const_get('YourClassName')
or if you are in a Rails app
byName= 'YourClassName'.constantize
Hope this helps
Just first thoughts, but you can do:
eval(services.service("#{input[:service].capitalize}Service.new, #{input})") if valid_service? input[:service]
def valid_service?
w%(delete update insert).include? input[:service]
end
As folks will no doubt shout, eval needs to be used with alot of care

RSpec - trying to stub a method that returns its own argument

I have a method which I'm trying to stub out in my unit test. The real method gets called with one argument (a string) and then sends out a text message. I need to stub out the method but return the string that gets passed in as an argument.
The code I have in my RSpec test is this:
allow(taxi_driver).to receive(:send_text).with(:string).and_return(string)
This returns:
NameError: undefined local variable or method 'string'
If I change the return argument to :string, I get the following error:
Please stub a default value first if message might be received with other args as well
I've tried googling and checking the relishapp.com site, but can't find the answer to something which appears quite simple and straightforward.
You can pass a block:
allow(taxi_driver).to receive(:send_text).with(kind_of(String)){|string| string }
expect(taxi_driver.send_text("123")).to eq("123")
My method is being called like this: send_text("the time now is #{Time.now}"). The string varies according to the time, thats why I need the mock to return the varying string. Perhaps its not within the scope of a mock to do this?
In such a case, I usually use Timecop gem in order to freeze system time. Here is a sample use case:
describe "#send_text" do
let(:taxi_driver) { TaxiDriver.new }
before do
Timecop.freeze(Time.local(2016, 1, 30, 12, 0, 0))
end
after do
Timecop.return
end
example do
expect(taxi_driver.send_text("the time now is #{Time.now}")).to eq \
"the time now is 2016-01-30 12:00:00 +0900"
end
end

how to read parameters from console to method in groovy?

I am new to groovy.I am reading values for 2 variables from console with below lines of code.
System.in.withReader {
println "Version: "
version = it.readLine()
println "Doc Type:"
Doc=it.readLine()
call getBillID(version,Doc)
}
getBillid method is as below,
def getBillID(int version,int doc)
{
allNodes.BillID.each {
theregularExpression=/\d+_\d+_\d+_\d_\d+_\d+_\d_${version}_${Doc}_\d+_\d+/
if(it != "" && it =~ theregularExpression) {
println "******" + it
}
}
}
now i want to use those variable values in my getBILLID method but i am getting error as
No signature of method: ReadXML.getBillID() is applicable for argument types: (java.lang.String, java.lang.String) values: [9, ]
where i went wrong.can any one tell me plz..
In addition to #Kalarani's answer, you could also do this:
System.in.withReader {
print "Version: "
int version = it.readLine() as int
print "Doc Type: "
int doc = it.readLine() as int
getBillID( version, doc )
}
As an aside; I would be careful with your capitalisation and variable names, ie: you have a variable called Doc with a capital letter. This is not the standard naming scheme, and you are best using all lowercase for variable names. You can see where it has got confused in the getBillID method. The parameter is called doc (all lowercase), but in the regular expression you reference ${Doc} (uppercase again).
This sort of thing is going to end up causing you a world of pain and bugs that might take you longer to find
Where is the getBillId() method defined? and what is the signature of the method? It would help understanding your problem if you could post that.

groovy while loop syntax assigning and checking a variable

I was reading a blog post and saw a groovy snippet that looked lik
while ( entry = inputStream.nextEntry ) {
// do something
}
In the while loop, is this groovy syntax that will cause the loop to break when entry is null?
Yes, but it will probably make the compiler complain about
a possible accidental assignment. A better practise is:
while ((entry = inputStream.nextEntry )!=null) {}
First week using Groovy and wanted to test this out. Thought I would share the test & results. Thanks for pointing this out.
def list = ['one', 'two', null, 'four']
def it = list.iterator()
def i
while (i = it.next()) {
println i
}
Result: one
two

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