Add generate migration command and generator (#201)

---------

Co-authored-by: Sean Collins <sean@cllns.com>

lib/hanami/cli/commands/app.rb

@@ -43,6 +43,7 @@ def self.extended(base)
             register "generate", aliases: ["g"] do |prefix|
               prefix.register "action", Generate::Action
               prefix.register "component", Generate::Component
+              prefix.register "migration", Generate::Migration
               prefix.register "operation", Generate::Operation
               prefix.register "part", Generate::Part
               prefix.register "repo", Generate::Repo

lib/hanami/cli/commands/app/generate/command.rb

@@ -39,7 +39,7 @@ def generator_class
             # @since 2.2.0
             # @api private
             def call(name:, slice: nil, **)
-              normalized_slice = inflector.underscore(Shellwords.shellescape(slice)) if slice
+              normalized_slice = inflector.underscore(slice) if slice
               generator.call(app.namespace, name, normalized_slice)
             end
           end

lib/hanami/cli/commands/app/generate/migration.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+module Hanami
+  module CLI
+    module Commands
+      module App
+        module Generate
+          # @since 2.2.0
+          # @api private
+          class Migration < Command
+            argument :name, required: true, desc: "Migration name"
+            option :slice, required: false, desc: "Slice name"
+
+            example [
+              %(create_posts),
+              %(add_published_at_to_posts),
+              %(create_users --slice=admin),
+            ]
+
+            def generator_class
+              Generators::App::Migration
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/hanami/cli/commands/app/generate/repo.rb

@@ -37,8 +37,6 @@ def call(name:, slice: nil, **opts)
                                 else
                                   "#{inflector.singularize(name)}_repo"
                                 end
-              slice = inflector.underscore(slice) if slice
-
               super(name: normalized_name, slice: slice, **opts)
             end
           end

lib/hanami/cli/errors.rb

@@ -107,5 +107,17 @@ def initialize(option1, option2)
         super("`#{option1}' and `#{option2}' cannot be used together")
       end
     end
+
+    # @since 2.2.0
+    # @api public
+    class InvalidMigrationNameError < Error
+      def initialize(name)
+        super(<<~TEXT)
+          Invalid migration name: #{name}
+
+          Name must contain only letters, numbers, and underscores.
+        TEXT
+      end
+    end
   end
 end

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

@@ -0,0 +1,69 @@
+# frozen_string_literal: true
+
+module Hanami
+  module CLI
+    module Generators
+      module App
+        # @since 2.2.0
+        # @api private
+        class Migration
+          # @since 2.2.0
+          # @api private
+          def initialize(fs:, inflector:, out: $stdout)
+            @fs = fs
+            @inflector = inflector
+            @out = out
+          end
+
+          # @since 2.2.0
+          # @api private
+          def call(_app_namespace, name, slice, **_opts)
+            normalized_name = inflector.underscore(name)
+            ensure_valid_name(normalized_name)
+
+            base = if slice
+                     fs.join("slices", slice, "config", "db", "migrate")
+                   else
+                     fs.join("config", "db", "migrate")
+                   end
+
+            path = fs.join(base, file_name(normalized_name))
+
+            fs.write(path, FILE_CONTENTS)
+          end
+
+          private
+
+          attr_reader :fs, :inflector, :out
+
+          VALID_NAME_REGEX = /^[_a-z0-9]+$/
+          private_constant :VALID_NAME_REGEX
+
+          def ensure_valid_name(name)
+            unless VALID_NAME_REGEX.match?(name.downcase)
+              raise InvalidMigrationNameError.new(name)
+            end
+          end
+
+          def file_name(name)
+            "#{Time.now.strftime(VERSION_FORMAT)}_#{name}.rb"
+          end
+
+          VERSION_FORMAT = "%Y%m%d%H%M%S"
+          private_constant :VERSION_FORMAT
+
+          FILE_CONTENTS = <<~RUBY
+            # frozen_string_literal: true
+
+            ROM::SQL.migration do
+              # Add your migration here.
+              #
+              # See https://sequel.jeremyevans.net/rdoc/files/doc/migration_rdoc.html for details.
+            end
+          RUBY
+          private_constant :FILE_CONTENTS
+        end
+      end
+    end
+  end
+end

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

@@ -0,0 +1,71 @@
+# frozen_string_literal: true
+
+require "hanami"
+
+RSpec.describe Hanami::CLI::Commands::App::Generate::Migration, :app do
+  subject { described_class.new(fs: fs, inflector: inflector) }
+
+  let(:fs) { Hanami::CLI::Files.new(memory: true, out: out) }
+  let(:inflector) { Dry::Inflector.new }
+
+  let(:out) { StringIO.new }
+
+  def output
+    out.string.strip
+  end
+
+  let(:app) { Hanami.app.namespace }
+
+  let(:migration_file_contents) {
+    <<~RUBY
+      # frozen_string_literal: true
+
+      ROM::SQL.migration do
+        # Add your migration here.
+        #
+        # See https://sequel.jeremyevans.net/rdoc/files/doc/migration_rdoc.html for details.
+      end
+    RUBY
+  }
+
+  before do
+    allow(Time).to receive(:now) { Time.new(2024, 7, 13, 14, 6, 0) }
+  end
+
+  context "generating for app" do
+    it "generates a migration" do
+      subject.call(name: "create_posts")
+
+      expect(fs.read("config/db/migrate/20240713140600_create_posts.rb")).to eq migration_file_contents
+      expect(output).to eq("Created config/db/migrate/20240713140600_create_posts.rb")
+    end
+
+    it "generates a migration with underscored version of camel cased name" do
+      subject.call(name: "CreatePosts")
+
+      expect(fs.read("config/db/migrate/20240713140600_create_posts.rb")).to eq migration_file_contents
+      expect(output).to eq("Created config/db/migrate/20240713140600_create_posts.rb")
+    end
+
+    it "raises an error if given an invalid name" do
+      expect {
+        subject.call(name: "create posts")
+      }.to raise_error(include_in_order(
+                         "Invalid migration name: create posts",
+                         "Name must contain only letters, numbers, and underscores."
+                       ))
+    end
+  end
+
+  context "generating for a slice" do
+    it "generates a migration" do
+      fs.mkdir("slices/main")
+      out.truncate 0
+
+      subject.call(name: "create_posts", slice: "main")
+
+      expect(fs.read("slices/main/config/db/migrate/20240713140600_create_posts.rb")).to eq migration_file_contents
+      expect(output).to eq("Created slices/main/config/db/migrate/20240713140600_create_posts.rb")
+    end
+  end
+end