Properly testing nested if conditionals.

nested_context_example.rb

# This is an example of how to properly structure your tests when handle nested conditions.
# When our test structure represents the code structure, it enables us to better understand the code and  more easily identify gaps in our testing coverage.

# Take an elseif condition for example
if x
  put x
elsif y
  put y
else
 put z
end

# The above is shorthand for
if x
 put x
else
  if y
    put y
  else
    put z
  end
end

# Test structure for the above two examples with incorrectly nested contexts
context when x is true
  it prints x to the screen
context when y is true
  it prints y to the screen
context when y is false
  it prints z to the screen

# This doesn't represent the code structure, this is not only confusing, but it makes it harder to identify missing coverage.

# Test structure for the above two examples with correctly nested contexts

context when x is true
  it prints x to the screen
context when x is false
  it does not print x to the screen
  
  context when y is true
    it prints y to the screen
  context when y is false
    it prints z to the screen

# Looking at this I understand precisely what the logic is.


# Example with an additional to level if statement
if x
  put x
elsif y
  put y
else
 put z
end

if a
  put a
else
  put b


# The above example with correctly nested contexts
  

context when x is true
  it prints x to the screen
context when x is not true
  it does not print x to the screen
  
  context when y is true
    it prints y to the screen
  context when y is false
    it prints z to the screen

context when a is true
  it prints a to the screen
context when a is false
  it prints b to the screen
  
# When contexts are properly nested it's possible to distinguish an nested condition from another top level condition.