Add a validation and fixer for modal submit buttons when inputs are present

Author: davidcelis

lib/block_kit/surfaces/modal.rb

@@ -50,7 +50,9 @@ class Modal < Base
       fixes :close, truncate: {maximum: MAX_BUTTON_LENGTH}, null_value: {error_types: [:blank]}
 
       validates :submit, presence: true, length: {maximum: MAX_BUTTON_LENGTH}, allow_nil: true
+      validate :submit_present_if_contains_input
       fixes :submit, truncate: {maximum: MAX_BUTTON_LENGTH}, null_value: {error_types: [:blank]}
+      fix :add_default_submit_button
 
       def initialize(attributes = {})
         attributes = attributes.with_indifferent_access
@@ -69,6 +71,20 @@ def as_json(*)
           submit_disabled: submit_disabled
         ).compact
       end
+
+      private
+
+      def submit_present_if_contains_input
+        errors.add(:submit, "can't be blank when blocks contain input elements") if contains_input? && submit.blank?
+      end
+
+      def add_default_submit_button
+        self.submit = "Submit" if contains_input? && submit.blank?
+      end
+
+      def contains_input?
+        blocks.any? { |block| block.is_a?(Layout::Input) }
+      end
     end
   end
 end

spec/block_kit/surfaces/modal_spec.rb

@@ -255,7 +255,7 @@
     end
   end
 
-  context "validates" do
+  context "validations" do
     it { is_expected.to validate_length_of(:private_metadata).is_at_most(3000).allow_nil }
     it { is_expected.to validate_length_of(:callback_id).is_at_most(255).allow_nil }
     it { is_expected.to validate_length_of(:external_id).is_at_most(255).allow_nil }
@@ -340,6 +340,22 @@
       expect(modal.errors["blocks[2].elements[0]"]).to include("is invalid: can't set focus_on_load when other elements have set focus_on_load")
       expect(modal.errors["blocks[2].elements[2]"]).to include("is invalid: can't set focus_on_load when other elements have set focus_on_load")
     end
+
+    it "validates that a submit button is present if there are inputs" do
+      modal.header(text: "Header text")
+      modal.section(text: "Info text")
+
+      expect(modal).to be_valid
+
+      modal.input(label: "Input label", element: BlockKit::Elements::PlainTextInput.new)
+
+      expect(modal).not_to be_valid
+      expect(modal.errors[:submit]).to include("can't be blank when blocks contain input elements")
+
+      modal.submit = "Submit"
+      expect(modal).to be_valid
+      expect(modal.errors[:submit]).to be_empty
+    end
   end
 
   it "fixes individually-contained blocks" do
@@ -417,6 +433,20 @@
     }.from(true).to(false)
   end
 
+  it "fixes missing submit buttons when blocks contain inputs" do
+    modal.header(text: "Header text")
+    modal.section(text: "Info text")
+    modal.input(label: "Input label", element: BlockKit::Elements::PlainTextInput.new)
+
+    expect {
+      modal.fix_validation_errors
+    }.to change {
+      modal.submit
+    }.from(nil).to(BlockKit::Composition::PlainText.new(text: "Submit"))
+
+    expect(modal).to be_valid
+  end
+
   it "can raise unfixed validation errors" do
     modal.header(text: "")
     modal.divider