graph class and weighted class graph

README.md

@@ -7,17 +7,78 @@
 ## Usage
 
 ```ruby
-graph = Graph.new(path_to_file)
+#simple not weighted graph
+# json import
+graph = Graph.load_from_json(path)
+
+#initialization from hash
+hash_graph = {1 => [2, 3], 2 => [1, 4]}
+graph = Graph.adjacency_list_init(hash_graph)
+
+graph.vertices #return list of vertices
+graph.edges #return list of edges
+```
+```ruby
+#adding new vertex (vertex could be numbers,chars .etc)
+# if vertex is already exists it will not be added
+graph.insert_vertex(new_vertex)
+```
+```ruby
+#adding new edge for simple Graph
+# vertices will also be included in vertices list of graph if they are not there
+# also add second_vertex to adjacency_list of first_vertex 
+graph.insert_edge([first_vertex, second_vertex])
+```
+```ruby
+graph.output_to_standard_stream # prints graph(adjacency_list)
+```
+```ruby
+#will create(overwrite) json_file and save adjacency_list in it
+#json_file name must ends with .json 
+graph.dump_to_json(path_to_file)
+```
+
+```ruby
+WeightedGraph - weighted_adjacency_list
+
+# json import
+# will raise error if 
+graph = WeightedGraph.load_from_json(path)
+
+#initialization from hash
+hash_graph = {1 => [[2, 3]], 2 => [[1, 4]]}
+graph = WeightedGraph.adjacency_list_init(hash_graph)
+
 graph.vertices #return list of vertices
+graph.edges #return list of edges
+
+#v1,v2 vertices,w - weight
+graph.insert_edge([v1,[v2,w]])
 ```
+
 ## Data formats
 
-```json
+```
+for simple not weighted Graph class
 {
   "1":[2],
   "2":[3],
-  "3":[1]
+  "3":[1,4]
+  "4": []
 }
+
+hash = {1 => [2,3]}
+
+for weightedGraph 
+{
+  "1":[[2,1]],
+  "2":[[3,4]],
+  "3":[[1,5],[4,6]]
+  "4": []
+}
+
+hash = {1 => [[2,3], [3,4]]}
+
 ```
 
 

lib/visual_graphs.rb

@@ -4,4 +4,11 @@
 require_relative "visual_graphs/graph"
 module VisualGraphs
   class Error < StandardError; end
+
+  class InvalidJSONFileNameError < RuntimeError; end
+
+  class IncorrectArgumentsForGraphInit < StandardError;end
+  # error for wrong parameters  in weighted graph initialization
+  class WrongParamsForWeightedGraphInit< StandardError;end
+
 end

lib/visual_graphs/graph.rb

@@ -4,24 +4,80 @@
 
 module VisualGraphs
   class Graph
-    def initialize(path)
-      file = File.open(path)
+    attr_accessor :adjacency_list
+    attr_accessor :edges
+
+    def initialize
       @adjacency_list = {}
       @edges = []
+    end
+
+    def self.load_from_json(path)
+      graph = Graph.new
+      file = File.open(path)
       temp = JSON.load(file)
       temp.each do |k, v|
         temp_k = k.to_i
-        @adjacency_list[temp_k] = v
-        v.each { |adj_vertex| @edges << [temp_k, adj_vertex] }
+        graph.adjacency_list[temp_k] = v
+        v.each { |adj_vertex|  graph.edges << [temp_k, adj_vertex] }
+      end
+      file.close
+      graph
+    end
+
+
+    def self.adjacency_list_init(list)
+      graph = Graph.new
+      list.each do |pair|
+        graph.adjacency_list.store(pair[0], pair[1])
+        pair[1].each {|vertex| graph.edges << [pair[0], vertex] }
       end
+      graph
     end
 
-    def vertices()
+    def vertices
       @adjacency_list.keys
     end
 
-    def edges()
-      @edges
+
+    def insert_vertex(vertex)
+      unless @adjacency_list.keys.include? vertex
+        @adjacency_list[vertex] = []
+        return true
+      end
+      false
     end
+
+    # edge is array [1,2] , where 1 and 2 are vertex
+    # also will insert vertexes unless they are not in adjecency_list
+    def insert_edge(edge)
+      unless @edges.include? edge
+        insert_vertex(edge[0])
+        insert_vertex(edge[1])
+        @adjacency_list[edge[0]] << edge[1]
+        @edges << edge
+        return true
+      end
+      false
+    end
+
+    def output_to_standard_stream
+      @adjacency_list.each do |vertex, adjacency_list|
+        puts "#{vertex} : #{adjacency_list}"
+      end
+    end
+
+    def correct_path?(path)
+      path.is_a? String and path.end_with? '.json'
+    end
+
+    # will create json file and dump graph to it
+    # throws No such file or directory error
+    def dump_to_json(path)
+      raise InvalidJSONFileNameError unless correct_path? path
+
+      File.open(path, 'w') { |f| f.write(@adjacency_list.to_json) }
+    end
+
   end
 end

lib/visual_graphs/weighted_graph.rb

@@ -0,0 +1,54 @@
+require_relative 'graph'
+
+module  VisualGraphs
+  class WeightedGraph < VisualGraphs::Graph
+    def initialize()
+      super()
+    end
+
+     def self.load_from_json(path)
+       graph = Graph.load_from_json(path)
+       weighted_graph = WeightedGraph.new
+       weighted_graph.edges = graph.edges
+       weighted_graph.adjacency_list = graph.adjacency_list
+       graph_is_weighted?(graph.edges)
+       weighted_graph
+     end
+
+    def self.adjacency_list_init(list)
+      graph = Graph.adjacency_list_init(list)
+      weighted_graph = WeightedGraph.new
+      weighted_graph.edges = graph.edges
+      weighted_graph.adjacency_list = graph.adjacency_list
+      graph_is_weighted?(graph.edges)
+      weighted_graph
+    end
+
+    #check that all edges are: [v1, [v2,w]]
+    # v1,v2 - vertices , w - weight
+    def self.graph_is_weighted?(edges)
+      edges.each do |edge|
+        unless correct_edge?(edge)
+          raise WrongParamsForWeightedGraphInit
+        end
+      end
+    end
+
+    def self.correct_edge?(edge)
+      edge[1].is_a? Array and edge[1].length == 2
+    end
+
+    def insert_edge(edge)
+      if (WeightedGraph.correct_edge? edge) && !(@edges.include? edge)
+        insert_vertex(edge[0])
+        insert_vertex(edge[1][0])
+        @adjacency_list[edge[0]] << edge[1]
+        @edges << edge
+        return true
+        end
+      false
+    end
+
+  end
+
+end

test/adjacency_list_graph_test.rb

@@ -0,0 +1,99 @@
+require './test/test_helper'
+require 'json'
+
+class AdjacencyListGraphTest < Minitest::Test
+  include VisualGraphs
+
+  def setup
+    @filepath = 'test/resources/test_data.json'
+    @output_file_path = 'test/resources/output_test_data.json'
+    File.delete @output_file_path if File.exist? @output_file_path
+  end
+
+  def test_json_file_created_when_graph_was_dumped_to_json
+    graph = Graph.load_from_json(@filepath)
+    graph.dump_to_json(@output_file_path)
+    assert_equal true, File.exists?(@output_file_path), 'json file was not created'
+  end
+
+  def test_dumped_graph_in_json_file_is_correct
+      graph = Graph.load_from_json(@filepath)
+      graph.dump_to_json(@output_file_path)
+
+      init_file = File.open(@filepath)
+      dumped_file = File.open(@output_file_path)
+      initial_graph_json = JSON.load(init_file)
+      dumped_graph_json = JSON.load(dumped_file)
+      init_file.close
+      dumped_file.close
+      assert_equal initial_graph_json, dumped_graph_json, 'dump_to_json is not working'
+
+  end
+
+  def test_incorrect_json_file_name_raise_exception
+    assert_raises InvalidJSONFileNameError do
+      graph = Graph.load_from_json(@filepath)
+      graph.dump_to_json('test/incorrect')
+    end
+  end
+
+  def test_correct_vertices_adjacency_list_initialization
+    hash_graph = Graph.adjacency_list_init({1 => [2], 2 => [3], 3 => [1]})
+    assert_equal [1, 2, 3], hash_graph.vertices, 'vertices arrays do not match'
+  end
+
+  def test_correct_edges_adjacency_list_initialization
+    hash_graph = Graph.adjacency_list_init({1 => [2], 2 => [3], 3 => [1]})
+    assert_equal [[1, 2], [2, 3], [3, 1]], hash_graph.edges, 'edges arrays do not match'
+  end
+
+  def test_adding_edge_will_add_edge_to_adjacency_list
+    graph = Graph.load_from_json(@filepath)
+    graph.insert_edge([1, 5])
+    assert_equal true, graph.instance_variable_get(:@adjacency_list)[1].include?(5), 'vertex was not added to adjacency_list'
+  end
+
+  def test_existing_edge_will_not_be_inserted
+    graph = Graph.load_from_json(@filepath)
+    graph.insert_edge([1, 2])
+    assert_equal 1, graph.edges.count([1, 2])
+  end
+
+
+  def test_non_existent_edge_will_be_inserted
+    graph = Graph.load_from_json(@filepath)
+    graph.insert_edge([1,4])
+    assert_equal true, graph.edges.include?([1, 4]), 'new edge was not added'
+  end
+
+  def test_existing_vertice_will_not_be_inserted
+    graph = Graph.load_from_json(@filepath)
+    graph.insert_vertex(1)
+    assert_equal 1, graph.vertices.count(1), 'existing vertex has been added twice'
+  end
+
+  def test_non_existing_vertice_will_be_inserted
+    graph = Graph.load_from_json(@filepath)
+    graph.insert_vertex(10)
+    assert_equal true,graph.vertices.include?(10), 'vertex was not added'
+  end
+
+  def test_non_existent_vertice_will_be_added_while_inserting_edge
+    graph = Graph.load_from_json(@filepath)
+    graph.insert_edge([1,4])
+    assert_equal true, graph.vertices.include?(4), 'new vertex was not added during edge inserting'
+  end
+
+  def test_loop_edge_will_be_added
+    graph = Graph.load_from_json(@filepath)
+    graph.insert_edge([1, 1])
+    assert_equal true, graph.edges.include?([1, 1]), 'looped edge was not added'
+  end
+
+  def test_loop_edge_will_not_add_same_vertex_twice
+    graph = Graph.load_from_json(@filepath)
+    graph.insert_edge([4, 4])
+    assert_equal 1, graph.vertices.count(4), 'more than 1 vertex was added during looped-edge inserting'
+  end
+
+end

test/coverage/.last_run.json

@@ -0,0 +1,5 @@
+{
+  "result": {
+    "line": 100.0
+  }
+}

test/coverage/.resultset.json

@@ -0,0 +1,7 @@
+{
+  "Unit Tests": {
+    "coverage": {
+    },
+    "timestamp": 1636022168
+  }
+}