Provide a root to assets object (#136)

This makes it easier to use separate assets objects for different sets of compiled assets at different paths.

lib/hanami/assets.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require "json"
+require "pathname"
 require "zeitwerk"
 
 module Hanami
@@ -37,10 +38,15 @@ def self.gem_loader
     # @since 2.1.0
     attr_reader :config
 
+    # @api private
+    # @since 2.1.0
+    attr_reader :root
+
     # @api public
     # @since 2.1.0
-    def initialize(config:)
+    def initialize(config:, root:)
       @config = config
+      @root = Pathname(root)
     end
 
     # Returns the asset at the given path.
@@ -92,15 +98,13 @@ def crossorigin?(source_path)
     def manifest
       return @manifest if instance_variable_defined?(:@manifest)
 
-      unless config.manifest_path
-        raise ConfigError, "no manifest_path configured"
-      end
+      full_manifest_path = root.join(config.manifest_path)
 
-      unless File.exist?(config.manifest_path)
-        raise ManifestMissingError.new(config.manifest_path)
+      unless full_manifest_path.exist?
+        raise ManifestMissingError.new(full_manifest_path.to_s)
       end
 
-      @manifest = JSON.parse(File.read(config.manifest_path))
+      @manifest = JSON.parse(File.read(full_manifest_path))
     end
   end
 end

lib/hanami/assets/config.rb

@@ -17,6 +17,13 @@ class Config
       BASE_URL = ""
       private_constant :BASE_URL
 
+      # @!attribute [rw] manifest_path
+      #   @return [String, nil]
+      #
+      #   @api public
+      #   @since 2.1.0
+      setting :manifest_path, default: "assets.json"
+
       # @!attribute [rw] package_manager_run_command
       #   @return [String]
       #
@@ -51,13 +58,6 @@ class Config
       #   @since 2.1.0
       setting :base_url, constructor: -> url { BaseUrl.new(url.to_s) }
 
-      # @!attribute [rw] manifest_path
-      #   @return [String, nil]
-      #
-      #   @api public
-      #   @since 2.1.0
-      setting :manifest_path
-
       # @api public
       # @since 2.1.0
       def initialize(**values)

lib/hanami/assets/errors.rb

@@ -9,13 +9,6 @@ class Assets
     class Error < ::StandardError
     end
 
-    # Error raised when assets config is not valid.
-    #
-    # @api public
-    # @since 2.1.0
-    class ConfigError < Error
-    end
-
     # Error returned when the assets manifest file is missing.
     #
     # @api public

spec/integration/hanami/assets/manifest_spec.rb

@@ -3,16 +3,21 @@
 require "tmpdir"
 
 RSpec.describe "manifest handling" do
-  subject(:assets) { Hanami::Assets.new(config: Hanami::Assets::Config.new(**config_kwargs)) }
+  subject(:assets) {
+    Hanami::Assets.new(
+      config: Hanami::Assets::Config.new(**config_kwargs),
+      root: root,
+    )
+  }
 
   let(:config_kwargs) { {} }
 
   context "manifest_path configured and real file exists" do
-    let(:config_kwargs) { {manifest_path: File.join(@dir, "manifest.json")} }
+    let(:root) { @dir }
 
     before do
       @dir = Dir.mktmpdir
-      File.write(File.join(@dir, "manifest.json"), <<~JSON)
+      File.write(File.join(@dir, "assets.json"), <<~JSON)
         {
           "app.js": {"url": "/path/to/app.js"}
         }
@@ -33,19 +38,12 @@
     end
   end
 
-  context "manifest_path not configured" do
-    it "raises a ConfigError" do
-      expect { assets["app.js"] }
-        .to raise_error Hanami::Assets::ConfigError, "no manifest_path configured"
-    end
-  end
-
   context "no file at configured manifest_path" do
-    let(:config_kwargs) { {manifest_path: "/missing/manifest.json"} }
+    let(:root) { "/missing/dir" }
 
     it "raises a ManifestMissingError" do
       expect { assets["app.js"] }
-        .to raise_error Hanami::Assets::ManifestMissingError, %r{/missing/manifest.json}
+        .to raise_error Hanami::Assets::ManifestMissingError, %r{/missing/dir/assets.json}
     end
   end
 end