Give tree children names

This means the get_or_create can work based on name, rather than
value.

This fixed duplicate pages appearing.

lib/obsidian/parser/page.rb

@@ -176,7 +176,7 @@ def get_or_create_child(title:, slug:, last_modified: nil, content: nil, content
         source_path: source_path
       )
 
-      child = @tree.add_child_unless_exists(value)
+      child = @tree.add_child_unless_exists(value.slug, value)
       @content_store[slug] = content unless content.nil?
       page = Page.new(child, @content_store, parent: self, root: root, media_root: media_root)
       @child_pages[slug] ||= page

lib/obsidian/parser/tree.rb

@@ -4,42 +4,44 @@ module Obsidian
   class Tree
     def initialize(value)
       @value = value
-      @children = []
+      @children = {}
     end
 
-    attr_reader :children
     attr_reader :value
 
+    def children
+      @children.values
+    end
+
     def inspect
       "Tree(#{value.inspect}) [#{children.length} children]"
     end
 
-    def add_child(value)
+    def add_child(key, value)
       node = Tree.new(value)
-      children << node
-      node
+      @children[key] = node
     end
 
-    def get_child(value)
-      children.find { |child| child.value == value }
+    def get_child(key)
+      @children[key]
     end
 
-    def child_exists(value)
-      children.any? { |node| node.value == value }
+    def child_exists(key)
+      @children.include?(key)
     end
 
-    def add_child_unless_exists(value)
-      child = get_child(value)
+    def add_child_unless_exists(key, value)
+      child = @children[key]
       return child unless child.nil?
-      add_child(value)
+      add_child(key, value)
     end
 
-    def remove_child(value)
-      children.delete_if { |node| node.value == value }
+    def remove_child(key)
+      @children.delete(key)
     end
 
     def is_index?
-      children.length > 0
+      @children.length > 0
     end
 
     def find(&block)
@@ -59,11 +61,11 @@ def walk(&block)
     end
 
     def remove_all(&block)
-      @children = @children.delete_if do |node|
+      @children = @children.delete_if do |key, node|
         block.call(node.value)
       end
 
-      @children.each do |child|
+      children.each do |child|
         child.remove_all(&block)
       end
     end

spec/obsidian/parser/tree_spec.rb

@@ -5,9 +5,9 @@
 
   describe("creating, retrieving, and removing nodes") do
     before do
-      foo = root.add_child(:foo)
-      foo.add_child(:bar)
-      foo.add_child(:baz)
+      foo = root.add_child("a", :foo)
+      foo.add_child("a", :bar)
+      foo.add_child("b", :baz)
     end
 
     it "can find a node from the root" do
@@ -24,7 +24,7 @@
     end
 
     it "can remove nodes" do
-      root.remove_child(:foo)
+      root.remove_child("a")
       expect(root.children).to be_empty
     end