Add docs for ExampleHooks

src/spectator/example_hooks.cr

@@ -1,5 +1,9 @@
 module Spectator
+  # Collection of hooks that run at various times throughout testing.
+  # A hook is just a `Proc` (code block) that runs at a specified time.
   class ExampleHooks
+    # Creates an empty set of hooks.
+    # This will effectively run nothing extra while running a test.
     def self.empty
       new(
         [] of ->,
@@ -10,6 +14,7 @@ module Spectator
       )
     end
 
+    # Creates a new set of hooks.
     def initialize(
       @before_all : Array(->),
       @before_each : Array(->),
@@ -19,30 +24,45 @@ module Spectator
     )
     end
 
+    # Runs all `before_all` hooks.
+    # These hooks should be run once before all examples in the group start.
     def run_before_all
       @before_all.each &.call
     end
 
+    # Runs all `before_each` hooks.
+    # These hooks should be run every time before each example in a group.
     def run_before_each
       @before_each.each &.call
     end
 
+    # Runs all `after_all` hooks.
+    # These hooks should be run once after all examples in group finish.
     def run_after_all
       @after_all.each &.call
     end
 
+    # Runs all `after_each` hooks.
+    # These hooks should be run every time after each example in a group.
     def run_after_each
       @after_each.each &.call
     end
 
+    # Creates a proc that runs the `around_each` hooks
+    # in addition to a block passed to this method.
+    # To call the block and all `around_each` hooks,
+    # just invoke `Proc#call` on the returned proc.
     def wrap_around_each(&block : ->)
       wrapper = block
+      # Must wrap in reverse order,
+      # otherwise hooks will run in the wrong order.
       @around_each.reverse_each do |hook|
         wrapper = wrap_proc(hook, wrapper)
       end
       wrapper
     end
 
+    # Utility method for wrapping one proc with another.
     private def wrap_proc(inner : Proc(Nil) ->, wrapper : ->)
       ->{ inner.call(wrapper) }
     end