DEV: First pass of ThemeSettingsObjectValidator (#25624)

Why this change?

This is a first pass at adding an objects validator which main's job is
to validate an object against a defined schema which we will support. In
this pass, we are simply validating that properties that has been marked
as required are present in the object.

config/locales/server.en.yml

@@ -134,6 +134,8 @@ en:
       string_value_not_valid_min_max: "It must be between %{min} and %{max} characters long."
       string_value_not_valid_min: "It must be at least %{min} characters long."
       string_value_not_valid_max: "It must be at most %{max} characters long."
+      objects:
+        required: "must be present"
     locale_errors:
       top_level_locale: "The top level key in a locale file must match the locale name"
       invalid_yaml: "Translation YAML invalid"

lib/theme_settings_object_validator.rb

@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+class ThemeSettingsObjectValidator
+  def initialize(schema:, object:)
+    @object = object
+    @schema_name = schema[:name]
+    @properties = schema[:properties]
+    @errors = {}
+  end
+
+  def validate
+    validate_required_properties
+
+    @properties.each do |property_name, property_attributes|
+      if property_attributes[:type] == "objects"
+        @object[property_name]&.each do |child_object|
+          @errors[property_name] ||= []
+
+          @errors[property_name].push(
+            self.class.new(schema: property_attributes[:schema], object: child_object).validate,
+          )
+        end
+      end
+    end
+
+    @errors
+  end
+
+  private
+
+  def validate_required_properties
+    @properties.each do |property_name, property_attributes|
+      if property_attributes[:required] && @object[property_name].nil?
+        @errors[property_name] ||= []
+        @errors[property_name] << I18n.t("themes.settings_errors.objects.required")
+      end
+    end
+  end
+end

spec/lib/theme_settings_object_validator_spec.rb

@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+RSpec.describe ThemeSettingsObjectValidator do
+  describe "#validate" do
+    it "should return the right array of error messages when properties are required but missing" do
+      schema = {
+        name: "section",
+        properties: {
+          title: {
+            type: "string",
+            required: true,
+          },
+          description: {
+            type: "string",
+            required: true,
+          },
+          links: {
+            type: "objects",
+            schema: {
+              name: "link",
+              properties: {
+                name: {
+                  type: "string",
+                  required: true,
+                },
+                child_links: {
+                  type: "objects",
+                  schema: {
+                    name: "child_link",
+                    properties: {
+                      title: {
+                        type: "string",
+                        required: true,
+                      },
+                      not_required: {
+                        type: "string",
+                      },
+                    },
+                  },
+                },
+              },
+            },
+          },
+        },
+      }
+
+      errors = described_class.new(schema:, object: {}).validate
+
+      expect(errors).to eq(title: ["must be present"], description: ["must be present"])
+
+      errors =
+        described_class.new(
+          schema: schema,
+          object: {
+            links: [{ child_links: [{}, {}] }, {}],
+          },
+        ).validate
+
+      expect(errors).to eq(
+        title: ["must be present"],
+        description: ["must be present"],
+        links: [
+          {
+            name: ["must be present"],
+            child_links: [{ title: ["must be present"] }, { title: ["must be present"] }],
+          },
+          { name: ["must be present"] },
+        ],
+      )
+    end
+  end
+end