Ruby yield keyword usage examples

Yield keyword I understand this, use it to occupy a position, first mark the next place in the future to write code, wait until the call, then write the specific code. A bit like a function pointer, or a delegate in C #, but it's not quite the same.

When writing the test interface, the Assert return value is not the same each time, but the function body is mostly the same, only the parameters are different. Just recently saw yield, familiar with the use, you can put the assert this part of code written in the position of yield.

The main example is the definition of this function and its invocation test_nodes.

Code:

 
 1 def generate_nodes(n=3)
 2     return n
 3 end
 4 
 5 def add_nodes(url,node)
 6     if node % 2 == 0
 7         return "message", 200
 8     else
 9         return "error", 500
10     end
11 end
12 
13 def test_nodes(nodes)
14     nodes.each do |node|
15       2.times do
16           #somecode       
17           restr, rcode = add_nodes("url",node)
18           yield restr, rcode, node
19       end
20    end
21 end
22 
23 nodes_list = [generate_nodes, generate_nodes(4),generate_nodes(5),generate_nodes(6)]
24 
25 test_nodes(nodes_list) do |restr, rcode, node|
26     if restr == "message" && rcode == 200  then #assert return value
27         puts "success"
28     else
29         puts "failed: node is #{node}"
30     end
31 end

Ruby yield keyword usage examples