Add stricter address validations

Updates the address validations to be stricter. We now require at least
a single letter in the street part of the address, only letters and
punctuation in the town / city name (no numbers), and at least a letter
or digit in the house name / number field.

app/forms/address_form.rb

@@ -11,6 +11,10 @@ class AddressForm < Form
   ADDRESS_MAX_CHARS = 100
   POSTCODE_MAX_CHARS = 11
 
+  ADDRESS_LINE_1_VALIDATION = /\A(?=.*[a-zA-Z0-9])[\w\s,.'-]+\z/
+  ADDRESS_LINE_2_VALIDATION = /\A(?=.*[a-zA-Z])[\w\s,.'-]+\z/
+  ADDRESS_LINE_3_VALIDATION = /\A[a-zA-Z\s,.'-]+\z/
+
   validates :address_line_1, presence: {message: i18n_error_message(:address_line_1_blank)}
   validates :address_line_2, presence: {message: i18n_error_message(:address_line_2_blank)}
   validates :address_line_3, presence: {message: i18n_error_message(:address_line_3_blank)}
@@ -23,9 +27,9 @@ class AddressForm < Form
   validates :address_line_4, length: {maximum: ADDRESS_MAX_CHARS, message: i18n_error_message(:address_line_max_chars)}
   validates :postcode, length: {maximum: POSTCODE_MAX_CHARS, message: i18n_error_message(:postcode_max_chars)}
 
-  validates :address_line_1, format: {with: ADDRESS_REGEX_FILTER, message: i18n_error_message(:address_format)}
-  validates :address_line_2, format: {with: ADDRESS_REGEX_FILTER, message: i18n_error_message(:address_format)}
-  validates :address_line_3, format: {with: ADDRESS_REGEX_FILTER, message: i18n_error_message(:address_format)}
+  validate :validate_address_line_1, if: -> { address_line_1.present? }
+  validate :validate_address_line_2, if: -> { address_line_2.present? }
+  validate :validate_address_line_3, if: -> { address_line_3.present? }
   validates :address_line_4, format: {with: ADDRESS_REGEX_FILTER, message: i18n_error_message(:address_format)}
 
   validate :postcode_is_valid, if: -> { postcode.present? }
@@ -51,4 +55,22 @@ def postcode_is_valid
       errors.add(:postcode, i18n_errors_path(:postcode_format))
     end
   end
+
+  def validate_address_line_1
+    unless ADDRESS_REGEX_FILTER.match(address_line_1) && ADDRESS_LINE_1_VALIDATION.match(address_line_1)
+      errors.add(:address_line_1, i18n_errors_path(:address_format))
+    end
+  end
+
+  def validate_address_line_2
+    unless ADDRESS_REGEX_FILTER.match(address_line_2) && ADDRESS_LINE_2_VALIDATION.match(address_line_2)
+      errors.add(:address_line_2, i18n_errors_path(:address_format))
+    end
+  end
+
+  def validate_address_line_3
+    unless ADDRESS_REGEX_FILTER.match(address_line_3) && ADDRESS_LINE_3_VALIDATION.match(address_line_3)
+      errors.add(:address_line_3, i18n_errors_path(:address_format))
+    end
+  end
 end

spec/forms/address_form_spec.rb

@@ -53,7 +53,7 @@
     end
 
     context "address lines too long" do
-      let(:over_one_hundred_chars) { Array.new(101) { [("a".."z"), ("A".."Z"), ("0".."9")].map(&:to_a).flatten.sample }.join }
+      let(:over_one_hundred_chars) { Array.new(101) { [("a".."z"), ("A".."Z")].map(&:to_a).flatten.sample }.join }
       let(:claim_params) do
         {
           address_line_1: over_one_hundred_chars,
@@ -77,25 +77,83 @@
     end
 
     context "address lines with format errors" do
-      let(:claim_params) do
-        {
-          address_line_1: "#123",
-          address_line_2: "Main $treet",
-          address_line_3: "$ome City",
-          address_line_4: "$som County",
-          postcode: "XXX XXXX"
-        }
+      context "with unpermitted characters" do
+        let(:claim_params) do
+          {
+            address_line_1: "#123",
+            address_line_2: "Main $treet",
+            address_line_3: "$ome City",
+            address_line_4: "$som County",
+            postcode: "XXX XXXX"
+          }
+        end
+
+        it "is invalid with format errors" do
+          is_expected.not_to be_valid
+
+          expect(form.errors.size).to eq 5
+          expect(form.errors[:address_line_1]).to eq([form.i18n_errors_path(:address_format)])
+          expect(form.errors[:address_line_2]).to eq([form.i18n_errors_path(:address_format)])
+          expect(form.errors[:address_line_3]).to eq([form.i18n_errors_path(:address_format)])
+          expect(form.errors[:address_line_4]).to eq([form.i18n_errors_path(:address_format)])
+          expect(form.errors[:postcode]).to eq([form.i18n_errors_path(:postcode_format)])
+        end
       end
 
-      it "is invalid with too format errors" do
-        is_expected.not_to be_valid
+      context "with invalid looking address" do
+        context "with an invalid line 1" do
+          let(:claim_params) do
+            {
+              address_line_1: ".",
+              address_line_2: "10 Downing Street",
+              address_line_3: "London",
+              postcode: "SW1A 2AA"
+            }
+          end
+
+          it "is invalid with format errors" do
+            is_expected.not_to be_valid
+
+            expect(form.errors.size).to eq 1
+            expect(form.errors[:address_line_1]).to eq([form.i18n_errors_path(:address_format)])
+          end
+        end
 
-        expect(form.errors.size).to eq 5
-        expect(form.errors[:address_line_1]).to eq([form.i18n_errors_path(:address_format)])
-        expect(form.errors[:address_line_2]).to eq([form.i18n_errors_path(:address_format)])
-        expect(form.errors[:address_line_3]).to eq([form.i18n_errors_path(:address_format)])
-        expect(form.errors[:address_line_4]).to eq([form.i18n_errors_path(:address_format)])
-        expect(form.errors[:postcode]).to eq([form.i18n_errors_path(:postcode_format)])
+        context "with an invalid line 2" do
+          let(:claim_params) do
+            {
+              address_line_1: "Flat 1",
+              address_line_2: ".",
+              address_line_3: "London",
+              postcode: "SW1A 2AA"
+            }
+          end
+
+          it "is invalid with format errors" do
+            is_expected.not_to be_valid
+
+            expect(form.errors.size).to eq 1
+            expect(form.errors[:address_line_2]).to eq([form.i18n_errors_path(:address_format)])
+          end
+        end
+
+        context "with an invalid line 3" do
+          let(:claim_params) do
+            {
+              address_line_1: "Flat 1",
+              address_line_2: "10 Downing Street",
+              address_line_3: "123",
+              postcode: "SW1A 2AA"
+            }
+          end
+
+          it "is invalid with format errors" do
+            is_expected.not_to be_valid
+
+            expect(form.errors.size).to eq 1
+            expect(form.errors[:address_line_3]).to eq([form.i18n_errors_path(:address_format)])
+          end
+        end
       end
     end
   end