Initial addition of pre- and post-conditions

src/spectator/dsl/builder.cr

@@ -91,6 +91,14 @@ module Spectator::DSL
       current_group.add_around_each_hook(block)
     end
 
+    def add_pre_condition(&block : ->) : Nil
+      current_group.add_pre_condition(block)
+    end
+
+    def add_post_condition(&block : ->) : Nil
+      current_group.add_post_condition(block)
+    end
+
     # Builds the entire spec and returns it as a test suite.
     # This should be called only once after the entire spec has been defined.
     protected def build : TestSuite

src/spectator/dsl/example_group_builder.cr

@@ -17,6 +17,10 @@ module Spectator::DSL
     @after_each_hooks = [] of ->
     @around_each_hooks = [] of Proc(Nil) ->
 
+    # Pre and post conditions so far.
+    @pre_conditions = [] of ->
+    @post_conditions = [] of ->
+
     # Adds a new example factory or group builder to this group.
     def add_child(child : Child)
       @children << child
@@ -49,6 +53,14 @@ module Spectator::DSL
       @around_each_hooks << block
     end
 
+    def add_pre_condition(block : ->) : Nil
+      @pre_conditions << block
+    end
+
+    def add_post_condition(block : ->) : Nil
+      @post_conditions << block
+    end
+
     # Constructs an `ExampleHooks` instance with all the hooks defined for this group.
     # This method should be only when the group is being built,
     # otherwise some hooks may be missing.
@@ -61,5 +73,9 @@ module Spectator::DSL
         @around_each_hooks
       )
     end
+
+    private def conditions
+      ExampleConditions.new(@pre_conditions, @post_conditions)
+    end
   end
 end

src/spectator/dsl/nested_example_group_builder.cr

@@ -25,7 +25,7 @@ module Spectator::DSL
     # The `parent` should be the group that contains this group.
     # The `sample_values` will be given to all of the examples (and groups) nested in this group.
     def build(parent : ExampleGroup, sample_values : Internals::SampleValues) : NestedExampleGroup
-      NestedExampleGroup.new(@what, parent, hooks).tap do |group|
+      NestedExampleGroup.new(@what, parent, hooks, conditions).tap do |group|
         # Set the group's children to built versions of the children from this instance.
         group.children = @children.map do |child|
           # Build the child and up-cast to prevent type errors.

src/spectator/dsl/root_example_group_builder.cr

@@ -6,7 +6,7 @@ module Spectator::DSL
     # Creates a `RootExampleGroup` which can have instances of `Example` and `ExampleGroup` nested in it.
     # The `sample_values` will be given to all of the examples (and groups) nested in this group.
     def build(sample_values : Internals::SampleValues) : RootExampleGroup
-      RootExampleGroup.new(hooks).tap do |group|
+      RootExampleGroup.new(hooks, conditions).tap do |group|
         # Set the group's children to built versions of the children from this instance.
         group.children = @children.map do |child|
           # Build the child and up-cast to prevent type errors.

src/spectator/dsl/sample_example_group_builder.cr

@@ -37,7 +37,7 @@ module Spectator::DSL
     def build(parent : ExampleGroup, sample_values : Internals::SampleValues) : NestedExampleGroup
       # This creates the container for the sub-groups.
       # The hooks are defined here, instead of repeating for each sub-group.
-      NestedExampleGroup.new(@what, parent, hooks).tap do |group|
+      NestedExampleGroup.new(@what, parent, hooks, conditions).tap do |group|
         # Set the container group's children to be sub-groups for each item in the collection.
         group.children = @collection.map do |value|
           # Create a sub-group for each item in the collection.
@@ -55,7 +55,7 @@ module Spectator::DSL
     private def build_sub_group(parent : ExampleGroup, sample_values : Internals::SampleValues, value : T) : NestedExampleGroup
       # Add the value to sample values for this sub-group.
       sub_values = sample_values.add(@symbol, @name, value)
-      NestedExampleGroup.new(value.to_s, parent, ExampleHooks.empty).tap do |group|
+      NestedExampleGroup.new(value.to_s, parent, ExampleHooks.empty, ExampleConditions.empty).tap do |group|
         # Set the sub-group's children to built versions of the children from this instance.
         group.children = @children.map do |child|
           # Build the child and up-cast to prevent type errors.

src/spectator/dsl/structure_dsl.cr

@@ -1182,6 +1182,30 @@ module Spectator::DSL
       end
     end
 
+    macro pre_condition(&block)
+      def %condition : Nil
+        {{block.body}}
+      end
+
+      ::Spectator::DSL::Builder.add_pre_condition do
+        example = ::Spectator::Internals::Harness.current.example
+        instance = example.instance.as({{@type.id}})
+        instance.%condition
+      end
+    end
+
+    macro post_condition
+      def %condition : Nil
+        {{block.body}}
+      end
+
+      ::Spectator::DSL::Builder.add_post_condition do
+        example = ::Spectator::Internals::Harness.current.example
+        instance = example.instance.as({{@type.id}})
+        instance.%condition
+      end
+    end
+
     # Creates an example, or a test case.
     # The `what` argument describes "what" is being tested or asserted.
     # The block contains the code to run the test.

src/spectator/example_conditions.cr

@@ -0,0 +1,24 @@
+module Spectator
+  class ExampleConditions
+    def self.empty
+      new(
+        [] of ->,
+        [] of ->
+      )
+    end
+
+    def initialize(
+      @pre_conditions : Array(->),
+      @post_conditions : Array(->)
+    )
+    end
+
+    def run_pre_conditions
+      @pre_conditions.each &.call
+    end
+
+    def run_post_conditions
+      @post_conditions.each &.call
+    end
+  end
+end

src/spectator/example_group.cr

@@ -17,7 +17,7 @@ module Spectator
 
     # Creates the example group.
     # The hooks are stored to be triggered later.
-    def initialize(@hooks : ExampleHooks)
+    def initialize(@hooks : ExampleHooks, @conditions : ExampleConditions)
       @before_all_hooks_run = false
       @after_all_hooks_run = false
     end
@@ -129,6 +129,14 @@ module Spectator
       run_before_each_hooks
     end
 
+    def run_pre_conditions
+      @conditions.run_pre_conditions
+    end
+
+    def run_post_conditions
+      @conditions.run_post_conditions
+    end
+
     # Runs all of the `before_all` hooks.
     # This should run prior to any examples in the group.
     # The hooks will be run only once.

src/spectator/includes.cr

@@ -18,6 +18,7 @@ require "./runnable_example"
 require "./pending_example"
 require "./dummy_example"
 
+require "./example_conditions"
 require "./example_hooks"
 require "./example_group"
 require "./nested_example_group"

src/spectator/nested_example_group.cr

@@ -17,8 +17,8 @@ module Spectator
     # The parent's children must contain this group,
     # otherwise there may be unexpected behavior.
     # The `hooks` are stored to be triggered later.
-    def initialize(@what, @parent, hooks : ExampleHooks)
+    def initialize(@what, @parent, hooks : ExampleHooks, conditions : ExampleConditions)
-      super(hooks)
+      super(hooks, conditions)
     end
 
     # Runs all of the `before_all` hooks.
@@ -58,6 +58,16 @@ module Spectator
       parent.run_after_each_hooks
     end
 
+    def run_pre_conditions : Nil
+      super
+      parent.run_pre_conditions
+    end
+
+    def run_post_conditions : Nil
+      super
+      parent.run_post_conditions
+    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,

src/spectator/runnable_example.cr

@@ -70,8 +70,9 @@ module Spectator
       # Capture how long it takes to run the test code.
       result.elapsed = Time.measure do
         begin
-          # Actually run the example code.
+          group.run_pre_conditions
-          run_instance
+          run_instance # Actually run the example code.
+          group.run_post_conditions
         rescue ex # Catch all errors and handle them later.
           result.error = ex
         end