Return human readable error messages

README.md

@@ -39,7 +39,7 @@
 
 ### Getting checks in bulk
 
-```
+```ruby
 > check.to_hash
 => {
  :cloudflare_ip?=>false,
@@ -57,3 +57,15 @@
 > check.to_json
 => "{\"cloudflare_ip?\":false,\"old_ip_address?\":false,\"a_record?\":true,\"cname_record?\":false,\"valid_domain?\":true,\"apex_domain?\":true,\"should_be_a_record?\":true,\"pointed_to_github_user_domain?\":false,\"pages_domain?\":false,\"valid?\":true}"
 ```
+
+### Getting the reason a domain is invalid
+
+```ruby
+> check = GitHubPages::HealthCheck.new "developer.facebook.com"
+> check.valid?
+=> false
+> check.reason
+=> #<GitHubPages::HealthCheck::InvalidCNAME>
+> check.reason.message
+=> "CNAME does not point to GitHub Pages"
+```

lib/github-pages-health-check.rb

@@ -5,6 +5,9 @@
 require 'singleton'
 require_relative 'github-pages-health-check/version'
 require_relative 'github-pages-health-check/cloudflare'
+require_relative 'github-pages-health-check/errors/deprecated_ip'
+require_relative 'github-pages-health-check/errors/invalid_a_record'
+require_relative 'github-pages-health-check/errors/invalid_cname'
 
 class GitHubPages
   class HealthCheck
@@ -91,14 +94,16 @@ def to_hash
         :should_be_a_record?            => should_be_a_record?,
         :pointed_to_github_user_domain? => pointed_to_github_user_domain?,
         :pages_domain?                  => pages_domain?,
-        :valid?                         => valid?
+        :valid?                         => valid?,
+        :reason                         => reason
       }
     end
 
     def to_json
       to_hash.to_json
     end
 
+    # Runs all checks, raises an error if invalid
     def check!
       return unless dns
       return if cloudflare_ip?
@@ -109,13 +114,22 @@ def check!
     end
     alias_method :valid!, :check!
 
+    # Runs all checks, returns true if valid, otherwise false
     def valid?
       check!
       true
     rescue
       false
     end
 
+    # Return the error, if any
+    def reason
+      check!
+      nil
+    rescue StandardError => e
+      e
+    end
+
     def inspect
       "#<GitHubPages::HealthCheck @domain=\"#{domain}\" valid?=#{valid?}>"
     end

lib/github-pages-health-check/errors/deprecated_ip.rb

@@ -0,0 +1,9 @@
+class GitHubPages
+  class HealthCheck
+    class DeprecatedIP < StandardError
+      def message
+        "A record points to deprecated IP address"
+      end
+    end
+  end
+end

lib/github-pages-health-check/errors/invalid_a_record.rb

@@ -0,0 +1,9 @@
+class GitHubPages
+  class HealthCheck
+    class InvalidARecord < StandardError
+      def message
+        "Should not be an A record"
+      end
+    end
+  end
+end

lib/github-pages-health-check/errors/invalid_cname.rb

@@ -0,0 +1,9 @@
+class GitHubPages
+  class HealthCheck
+    class InvalidCNAME < StandardError
+      def message
+        "CNAME does not point to GitHub Pages"
+      end
+    end
+  end
+end

spec/github_pages_health_check_spec.rb

@@ -123,8 +123,15 @@ def cname_packet(domain)
 
   it "returns valid json" do
     data = JSON.parse GitHubPages::HealthCheck.new("benbalter.com").to_json
-    expect(data.length).to eql(10)
-    data.each { |key, value| expect([true,false].include?(value)).to eql(true) }
+    expect(data.length).to eql(11)
+    data.each { |key, value| expect([true,false,nil].include?(value)).to eql(true) }
+  end
+
+  it "return the error" do
+    check = GitHubPages::HealthCheck.new "developer.facebook.com"
+    expect(check.valid?).to eql(false)
+    expect(check.reason.class).to eql(GitHubPages::HealthCheck::InvalidCNAME)
+    expect(check.reason.message).to eql("CNAME does not point to GitHub Pages")
   end
 
 end