From bb8a9d3fd3c50b912195dcc9ef382991ccee8adf Mon Sep 17 00:00:00 2001
From: Iris Faraway <iris.faraway@gmail.com>
Date: Thu, 15 Feb 2018 14:29:50 +0000
Subject: [PATCH] Validate format of UK postcodes (#78)

---
 Gemfile                                            |  2 ++
 Gemfile.lock                                       |  3 ++-
 app/validators/temp_postcode_validator.rb          | 10 ++++++----
 config/locales/forms/company_postcode_forms/en.yml |  2 +-
 spec/forms/company_postcode_forms_spec.rb          |  4 ++--
 5 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/Gemfile b/Gemfile
index 320fb4163..1ca223ecf 100644
--- a/Gemfile
+++ b/Gemfile
@@ -58,6 +58,8 @@ gem "rest-client", "~> 2.0"
 
 gem "secure_headers", "~> 5.0"
 
+gem "uk_postcode", require: false
+
 group :development, :test do
   # Call "byebug" anywhere in the code to stop execution and get a debugger console
   gem "byebug"
diff --git a/Gemfile.lock b/Gemfile.lock
index 152acee40..c953d8476 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -237,6 +237,7 @@ GEM
       thread_safe (~> 0.1)
     uglifier (4.1.6)
       execjs (>= 0.3.0, < 3)
+    uk_postcode (2.1.2)
     unf (0.1.4)
       unf_ext
     unf_ext (0.0.7.5)
@@ -285,11 +286,11 @@ DEPENDENCIES
   spring
   turbolinks
   uglifier (>= 1.3.0)
+  uk_postcode
   vcr (~> 4.0)
   web-console (~> 2.0)
   webmock (~> 3.3)
 
-
 RUBY VERSION
    ruby 2.4.2p198
 
diff --git a/app/validators/temp_postcode_validator.rb b/app/validators/temp_postcode_validator.rb
index 048e12a76..052feb5a5 100644
--- a/app/validators/temp_postcode_validator.rb
+++ b/app/validators/temp_postcode_validator.rb
@@ -1,6 +1,8 @@
+require "uk_postcode"
+
 class TempPostcodeValidator < ActiveModel::Validator
   def validate(record)
-    postcode_returns_results?(record) if value_is_present?(record) && value_is_valid_length?(record)
+    postcode_returns_results?(record) if value_is_present?(record) && value_uses_correct_format?(record)
   end
 
   private
@@ -11,9 +13,9 @@ def value_is_present?(record)
     false
   end
 
-  def value_is_valid_length?(record)
-    return true if record.temp_postcode.length < 11
-    record.errors.add(:temp_postcode, :too_long)
+  def value_uses_correct_format?(record)
+    return true if UKPostcode.parse(record.temp_postcode).full_valid?
+    record.errors.add(:temp_postcode, :wrong_format)
     false
   end
 
diff --git a/config/locales/forms/company_postcode_forms/en.yml b/config/locales/forms/company_postcode_forms/en.yml
index 5bc35d1a3..4d3a555ff 100644
--- a/config/locales/forms/company_postcode_forms/en.yml
+++ b/config/locales/forms/company_postcode_forms/en.yml
@@ -17,7 +17,7 @@ en:
           attributes:
             temp_postcode:
               blank: "Enter a postcode"
-              too_long: "Enter a valid UK postcode"
+              wrong_format: "Enter a valid UK postcode"
               no_results: "We couldn't find any addresses for that postcode. Check the postcode or enter the address manually."
               os_places_error: "Our address finder isn't working."
             reg_identifier:
diff --git a/spec/forms/company_postcode_forms_spec.rb b/spec/forms/company_postcode_forms_spec.rb
index f77e7f354..4d94edf23 100644
--- a/spec/forms/company_postcode_forms_spec.rb
+++ b/spec/forms/company_postcode_forms_spec.rb
@@ -93,9 +93,9 @@
         end
       end
 
-      context "when a company_postcode is too long" do
+      context "when a company_postcode is in the wrong format" do
         before(:each) do
-          company_postcode_form.temp_postcode = "ABC123DEF567"
+          company_postcode_form.temp_postcode = "foo"
         end
 
         it "is not valid" do