Easy 01: Validate Phone Number [Example PR]

Solutions/Easy/01/is_valid_phone_number.rb

@@ -0,0 +1,4 @@
+def is_valid_phone_number(string)
+  # your code here...
+  false
+end

Solutions/Easy/01/valid_phone_number_test.rb

@@ -0,0 +1,40 @@
+require 'minitest/autorun'
+require_relative 'is_valid_phone_number'
+
+class ValidPhoneNumberTest < Minitest::Test
+  def test_when_valid_phone_number
+    assert is_valid_phone_number("(123) 456-7890")
+  end
+
+  def test_extra_extra_number_missing_bracket
+    refute is_valid_phone_number("1111)555 2345")
+  end
+
+  def test_with_missing_bracket
+    refute is_valid_phone_number("098) 123 4567")
+  end
+
+  def test_less_numbers
+    refute is_valid_phone_number("(0) 123-4567")
+  end
+
+  def test_more_numbers
+    refute is_valid_phone_number("(00111) 123-4567")
+  end
+
+  def test_dash_missing
+    refute is_valid_phone_number("(123) 456 7890")
+  end
+
+  def test_dash_in_wrong_place
+    refute is_valid_phone_number("(123)-456 7890")
+  end
+
+  def test_when_not_numbers
+    refute is_valid_phone_number("(abc) def-ghij")
+  end
+
+  def test_when_some_not_numbers
+    refute is_valid_phone_number("(123) 4a6-7890")
+  end
+end