FEATURE: support a description attribute on form template fields (#23744)

* FEATURE: support a description attribute on form template fields

spec/lib/validators/form_template_yaml_validator_spec.rb

@@ -0,0 +1,174 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+RSpec.describe FormTemplateYamlValidator, type: :validator do
+  subject(:validator) { described_class.new }
+
+  let(:form_template) { FormTemplate.new(template: yaml_content) }
+
+  describe "#validate" do
+    context "with valid YAML" do
+      let(:yaml_content) { <<~YAML }
+          - type: input
+            id: name
+            attributes:
+              label: "Full name"
+              placeholder: "eg. John Smith"
+              description: "What is your full name?"
+            validations:
+              required: true
+              minimum: 2
+              maximum: 100
+        YAML
+
+      it "does not add any errors" do
+        validator.validate(form_template)
+        expect(form_template.errors).to be_empty
+      end
+    end
+
+    context "with invalid YAML" do
+      let(:yaml_content) { "invalid_yaml_string" }
+
+      it "adds an error message for invalid YAML" do
+        validator.validate(form_template)
+        expect(form_template.errors[:template]).to include(
+          I18n.t("form_templates.errors.invalid_yaml"),
+        )
+      end
+    end
+  end
+
+  describe "#check_missing_fields" do
+    context "when type field is missing" do
+      let(:yaml_content) { <<~YAML }
+          - id: name
+            attributes:
+              label: "Full name"
+        YAML
+
+      it "adds an error for missing type field" do
+        validator.validate(form_template)
+        expect(form_template.errors[:template]).to include(
+          I18n.t("form_templates.errors.missing_type"),
+        )
+      end
+    end
+
+    context "when id field is missing" do
+      let(:yaml_content) { <<~YAML }
+          - type: input
+            attributes:
+              label: "Full name"
+        YAML
+
+      it "adds an error for missing id field" do
+        validator.validate(form_template)
+        expect(form_template.errors[:template]).to include(
+          I18n.t("form_templates.errors.missing_id"),
+        )
+      end
+    end
+  end
+
+  describe "#check_allowed_types" do
+    context "when YAML has invalid field types" do
+      let(:yaml_content) { <<~YAML }
+          - type: invalid_type
+            id: name
+            attributes:
+              label: "Full name"
+        YAML
+
+      it "adds an error for invalid field types" do
+        validator.validate(form_template)
+        expect(form_template.errors[:template]).to include(
+          I18n.t(
+            "form_templates.errors.invalid_type",
+            type: "invalid_type",
+            valid_types: FormTemplateYamlValidator::ALLOWED_TYPES.join(", "),
+          ),
+        )
+      end
+    end
+
+    context "when field type is allowed" do
+      let(:yaml_content) { <<~YAML }
+          - type: input
+            id: name
+        YAML
+
+      it "does not add an error for valid field type" do
+        validator.validate(form_template)
+        expect(form_template.errors[:template]).to be_empty
+      end
+    end
+  end
+
+  describe "#check_descriptions_html" do
+    context "when description field has safe HTML" do
+      let(:yaml_content) { <<~YAML }
+          - type: input
+            id: name
+            attributes:
+              label: "Full name"
+              description: "What is your full name? Details <a href='https://test.com'>here</a>."
+        YAML
+
+      it "does not add an error" do
+        validator.validate(form_template)
+        expect(form_template.errors[:template]).to be_empty
+      end
+    end
+
+    context "when description field has unsafe HTML" do
+      let(:yaml_content) { <<~YAML }
+          - type: input
+            id: name
+            attributes:
+              label: "Full name"
+              description: "What is your full name? Details <script>window.alert('hey');</script>."
+        YAML
+
+      it "adds a validation error" do
+        validator.validate(form_template)
+        expect(form_template.errors[:template]).to include(
+          I18n.t("form_templates.errors.unsafe_description"),
+        )
+      end
+    end
+  end
+
+  describe "#check_ids" do
+    context "when YAML has duplicate ids" do
+      let(:yaml_content) { <<~YAML }
+          - type: input
+            id: name
+          - type: input
+            id: name
+        YAML
+
+      it "adds an error for duplicate ids" do
+        validator.validate(form_template)
+        expect(form_template.errors[:template]).to include(
+          I18n.t("form_templates.errors.duplicate_ids"),
+        )
+      end
+    end
+
+    context "when YAML has reserved ids" do
+      let(:yaml_content) { <<~YAML }
+          - type: input
+            id: title
+        YAML
+
+      it "adds an error for reserved ids" do
+        validator.validate(form_template)
+        expect(form_template.errors[:template]).to include(
+          I18n.t("form_templates.errors.reserved_id", id: "title"),
+        )
+      end
+    end
+  end
+end