Generate base struct classes in generate struct if missing

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Break Versioning](https://www.taoensso.com/break-ve
 
 - Add `hanami new --skip-git` to generate an app without initializing a git repository or generating a `.gitignore`. (@aaronmallen #441)
 - Proper support for MariaDB (@katafrakt in #458)
+- Generate the app or slice base struct class (`db/struct.rb`) in `hanami generate struct` when it does not exist yet, as `hanami generate part` does for the base part. (@anyingiit in #465)
 
 ### Changed
 

lib/hanami/cli/generators/app/struct.rb

@@ -18,6 +18,9 @@ def initialize(fs:, inflector:, stdout: $stdout)
           # @since 2.2.0
           # @api private
           def call(key:, namespace:, base_path:, force: false)
+            create_app_base_struct_if_missing
+            create_slice_base_struct_if_missing(namespace:, base_path:) unless namespace == Hanami.app.namespace
+
             RubyClassFile.new(
               fs: fs,
               inflector: inflector,
@@ -32,6 +35,33 @@ def call(key:, namespace:, base_path:, force: false)
           private
 
           attr_reader :fs, :inflector, :stdout
+
+          def create_app_base_struct_if_missing
+            return if fs.exist?(fs.join(APP_DIR, "db", "struct.rb"))
+
+            RubyClassFile.new(
+              fs: fs,
+              inflector: inflector,
+              namespace: Hanami.app.namespace,
+              key: "db.struct",
+              base_path: APP_DIR,
+              parent_class_name: "Hanami::DB::Struct",
+              requires: ["hanami/db/struct"]
+            ).create
+          end
+
+          def create_slice_base_struct_if_missing(namespace:, base_path:)
+            return if fs.exist?(fs.join(base_path, "db", "struct.rb"))
+
+            RubyClassFile.new(
+              fs: fs,
+              inflector: inflector,
+              namespace: namespace,
+              key: "db.struct",
+              base_path: base_path,
+              parent_class_name: "#{Hanami.app.namespace}::DB::Struct"
+            ).create
+          end
         end
       end
     end

spec/unit/hanami/cli/commands/app/generate/struct_spec.rb

@@ -71,6 +71,43 @@ class Hardcover < Test::DB::Struct
       expect(output).to include("Created app/structs/book/published/hardcover.rb")
     end
 
+    context "without base struct" do
+      it "generates the app base struct" do
+        subject.call(name: "book")
+
+        base_struct = <<~EXPECTED
+          # frozen_string_literal: true
+
+          require "hanami/db/struct"
+
+          module Test
+            module DB
+              class Struct < Hanami::DB::Struct
+              end
+            end
+          end
+        EXPECTED
+
+        expect(fs.read("app/db/struct.rb")).to eq(base_struct)
+        expect(output).to include("Created app/db/struct.rb")
+      end
+    end
+
+    context "with base struct" do
+      before do
+        fs.write("app/db/struct.rb", "existing base struct")
+        stdout.truncate 0
+      end
+
+      it "does not overwrite the app base struct" do
+        subject.call(name: "book")
+
+        expect(fs.read("app/db/struct.rb")).to eq("existing base struct")
+        expect(output).not_to include("Created app/db/struct.rb")
+        expect(fs.exist?("app/structs/book.rb")).to be(true)
+      end
+    end
+
     context "with existing file" do
       let(:file_path) { "app/structs/book/published/hardcover.rb" }
 
@@ -127,6 +164,47 @@ class DraftBook < Main::DB::Struct
       expect(output).to include("Created slices/main/structs/book/draft_book.rb")
     end
 
+    context "without base structs" do
+      it "generates the app and slice base structs" do
+        fs.mkdir("slices/main")
+        subject.call(name: "book", slice: "main")
+
+        slice_base_struct = <<~EXPECTED
+          # frozen_string_literal: true
+
+          module Main
+            module DB
+              class Struct < Test::DB::Struct
+              end
+            end
+          end
+        EXPECTED
+
+        expect(fs.read("slices/main/db/struct.rb")).to eq(slice_base_struct)
+        expect(output).to include("Created slices/main/db/struct.rb")
+        expect(fs.exist?("app/db/struct.rb")).to be(true)
+        expect(output).to include("Created app/db/struct.rb")
+      end
+    end
+
+    context "with base structs" do
+      before do
+        fs.write("app/db/struct.rb", "existing app base struct")
+        fs.write("slices/main/db/struct.rb", "existing slice base struct")
+        stdout.truncate 0
+      end
+
+      it "does not overwrite the base structs" do
+        subject.call(name: "book", slice: "main")
+
+        expect(fs.read("app/db/struct.rb")).to eq("existing app base struct")
+        expect(fs.read("slices/main/db/struct.rb")).to eq("existing slice base struct")
+        expect(output).not_to include("Created app/db/struct.rb")
+        expect(output).not_to include("Created slices/main/db/struct.rb")
+        expect(fs.exist?("slices/main/structs/book.rb")).to be(true)
+      end
+    end
+
     context "with existing file" do
       let(:file_path) { "slices/main/structs/book/draft_book.rb" }