From bcb68a585627a1b7cd2e501b4d8cb9de8d4d767a Mon Sep 17 00:00:00 2001
From: Michael Miller <icy.arctic.fox@gmail.com>
Date: Sun, 14 Oct 2018 19:06:02 -0600
Subject: [PATCH] Implement example lookup by index

This will be used later for executing tests in random order.
---
 src/spectator/example.cr           |  5 +++++
 src/spectator/example_component.cr |  3 +++
 src/spectator/example_group.cr     | 19 +++++++++++++++++++
 3 files changed, 27 insertions(+)

diff --git a/src/spectator/example.cr b/src/spectator/example.cr
index bcb58f8..f3dd39c 100644
--- a/src/spectator/example.cr
+++ b/src/spectator/example.cr
@@ -34,6 +34,11 @@ module Spectator
       1
     end
 
+    # Retrieve the current example.
+    def [](index : Int)
+      self
+    end
+
     # String representation of the example.
     # This consists of the groups the example is in and the description.
     # The string can be given to end-users to identify the example.
diff --git a/src/spectator/example_component.cr b/src/spectator/example_component.cr
index fdb24d7..7814960 100644
--- a/src/spectator/example_component.cr
+++ b/src/spectator/example_component.cr
@@ -10,5 +10,8 @@ module Spectator
 
     # The number of examples in this instance.
     abstract def example_count : Int
+
+    # Lookup the example with the specified index.
+    abstract def [](index : Int) : Example
   end
 end
diff --git a/src/spectator/example_group.cr b/src/spectator/example_group.cr
index 9c63633..4277fd6 100644
--- a/src/spectator/example_group.cr
+++ b/src/spectator/example_group.cr
@@ -31,6 +31,25 @@ module Spectator
       children.sum(&.example_count)
     end
 
+    def [](index : Int) : Example
+      raise IndexError.new if index < 0
+      offset = index
+      found = children.find do |child|
+        count = child.example_count
+        if offset < count
+          true
+        else
+          offset -= count
+          false
+        end
+      end
+      if found
+        found[offset]
+      else
+        raise IndexError.new
+      end
+    end
+
     # TODO: Remove this method.
     def all_examples
       Array(Example).new(example_count).tap do |array|