Make capture_erb plugin call integrate better with erubi/capture_block

This has capture_erb call capture on the output buffer object if
it responds to it.  This can fix issues when inside the block
passed to capture_erb, there is a call to capture directly on the
buffer object.

CHANGELOG

@@ -1,3 +1,7 @@
+= master
+
+* Make capture_erb plugin call integrate better with erubi/capture_block (jeremyevans)
+
 = 3.81.0 (2024-06-12)
 
 * Make assets plugin :early_hints option follow Rack 3 SPEC if using Rack 3 (jeremyevans)

lib/roda/plugins/capture_erb.rb

@@ -15,6 +15,11 @@ module RodaPlugins
     # inside templates.  It can be combined with the inject_erb plugin
     # to wrap template blocks with arbitrary output and then inject the
     # wrapped output into the template.
+    #
+    # If the output buffer object responds to +capture+ (e.g. when
+    # +erubi/capture_block+ is being used as the template engine),
+    # this will call +capture+ on the output buffer object, instead
+    # of setting the output buffer object temporarily to a new object.
     module CaptureERB
       def self.load_dependencies(app)
         app.plugin :render
@@ -25,13 +30,20 @@ module InstanceMethods
         # with an empty string, and then yield to the block.
         # Return the value of the block, converted to a string.
         # Restore the previous ERB output buffer before returning.
-        def capture_erb
+        def capture_erb(&block)
           outvar = render_opts[:template_opts][:outvar]
           buf_was = instance_variable_get(outvar)
-          instance_variable_set(outvar, String.new)
-          yield.to_s
-        ensure
-          instance_variable_set(outvar, buf_was) if outvar && buf_was
+
+          if buf_was.respond_to?(:capture)
+            buf_was.capture(&block)
+          else
+            begin
+              instance_variable_set(outvar, String.new)
+              yield.to_s
+            ensure
+              instance_variable_set(outvar, buf_was) if outvar && buf_was
+            end
+          end
         end
       end
     end

spec/plugin/capture_erb_spec.rb

@@ -1,7 +1,7 @@
 require_relative "../spec_helper"
 
 begin
-  require 'tilt/erb'
+  require 'tilt'
 rescue LoadError
   warn "tilt not installed, skipping capture_erb plugin test"
 else
@@ -52,3 +52,55 @@ def some_method(&block)
   end
 end
 end
+
+begin
+  require 'tilt/erubi'
+  require 'erubi/capture_block'
+rescue LoadError
+  warn "tilt/erubi or erubi/capture not installed, skipping capture_erb plugin test for erubi/capture_block"
+else
+describe "capture_erb plugin with erubi/capture_block" do
+  before do
+    app(:bare) do
+      plugin :render, :views => './spec/views', template_opts: {engine_class: Erubi::CaptureBlockEngine}
+      plugin :capture_erb
+      plugin :inject_erb
+
+      route do |r|
+        r.root do
+          render(:inline => "<% value = capture_erb do %>foo<% end %>bar<%= value %>")
+        end
+        r.get 'rescue' do
+          render(:inline => "<% value = capture_erb do %>foo<% raise %><% end rescue (value = 'baz') %>bar<%= value %>")
+        end
+        r.get 'inject' do
+          render(:inline => "<%= some_method do %>foo<% end %>")
+        end
+        r.get 'outside' do
+          capture_erb{1}
+        end
+      end
+
+      def some_method(&block)
+        "bar#{capture_erb(&block).upcase}baz"
+      end
+    end
+  end
+
+  it "should capture erb output" do
+    body.strip.must_equal "barfoo"
+  end
+
+  it "should handle exceptions in captured blocks" do
+    body('/rescue').strip.must_equal "barbaz"
+  end
+
+  it "should work with the inject_erb plugin" do
+    body('/inject').strip.must_equal "barFOObaz"
+  end
+
+  it "should return result of block converted to string when used outside template" do
+    body('/outside').must_equal "1"
+  end
+end
+end