Fix and improve tests for source URI trailing slash normalization

- Fix setup_fake_source double-slash bug: normalize URI before
  registering spec data to prevent URL mismatch in load_specs
- Fix test_execute_add/append_https_rubygems_org: these tests were
  incorrectly expecting TermError due to the double-slash bug
- Fix test_execute_prepend_without_trailing_slash: correct expected
  source order (prepend adds to front, not end)
- Fix test_execute_remove_redundant_source_trailing_slash: path-less
  URIs are not modified by normalize_source_uri
- Use assert_equal for Gem.sources to improve failure diagnostics

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hsbt

test/rubygems/test_gem_commands_sources_command.rb

@@ -61,15 +61,15 @@ def test_execute_add
   end
 
   def test_execute_add_without_trailing_slash
-    setup_fake_source('https://rubygems.pkg.github.com/my-org')
+    setup_fake_source("https://rubygems.pkg.github.com/my-org")
 
     @cmd.handle_options %W[--add https://rubygems.pkg.github.com/my-org]
 
     use_ui @ui do
       @cmd.execute
     end
 
-    assert_equal [@gem_repo, 'https://rubygems.pkg.github.com/my-org/'], Gem.sources
+    assert_equal [@gem_repo, "https://rubygems.pkg.github.com/my-org/"], Gem.sources
 
     expected = <<-EOF
 https://rubygems.pkg.github.com/my-org/ added to sources
@@ -78,16 +78,17 @@ def test_execute_add_without_trailing_slash
     assert_equal expected, @ui.output
     assert_equal "", @ui.error
   end
+
   def test_execute_add_multiple_trailing_slash
-    setup_fake_source('https://rubygems.pkg.github.com/my-org/')
+    setup_fake_source("https://rubygems.pkg.github.com/my-org/")
 
     @cmd.handle_options %W[--add https://rubygems.pkg.github.com/my-org///]
 
     use_ui @ui do
       @cmd.execute
     end
 
-    assert_equal [@gem_repo, 'https://rubygems.pkg.github.com/my-org/'], Gem.sources
+    assert_equal [@gem_repo, "https://rubygems.pkg.github.com/my-org/"], Gem.sources
 
     expected = <<-EOF
 https://rubygems.pkg.github.com/my-org/ added to sources
@@ -98,15 +99,15 @@ def test_execute_add_multiple_trailing_slash
   end
 
   def test_execute_append_without_trailing_slash
-    setup_fake_source('https://rubygems.pkg.github.com/my-org')
+    setup_fake_source("https://rubygems.pkg.github.com/my-org")
 
     @cmd.handle_options %W[--append https://rubygems.pkg.github.com/my-org]
 
     use_ui @ui do
       @cmd.execute
     end
 
-    assert_equal [@gem_repo, 'https://rubygems.pkg.github.com/my-org/'], Gem.sources
+    assert_equal [@gem_repo, "https://rubygems.pkg.github.com/my-org/"], Gem.sources
 
     expected = <<-EOF
 https://rubygems.pkg.github.com/my-org/ added to sources
@@ -117,15 +118,15 @@ def test_execute_append_without_trailing_slash
   end
 
   def test_execute_prepend_without_trailing_slash
-    setup_fake_source('https://rubygems.pkg.github.com/my-org')
+    setup_fake_source("https://rubygems.pkg.github.com/my-org")
 
     @cmd.handle_options %W[--prepend https://rubygems.pkg.github.com/my-org]
 
     use_ui @ui do
       @cmd.execute
     end
 
-    assert_equal [@gem_repo, 'https://rubygems.pkg.github.com/my-org/'], Gem.sources
+    assert_equal ["https://rubygems.pkg.github.com/my-org/", @gem_repo], Gem.sources
 
     expected = <<-EOF
 https://rubygems.pkg.github.com/my-org/ added to sources
@@ -605,17 +606,14 @@ def test_execute_add_https_rubygems_org
 
     @cmd.handle_options %W[--add #{https_rubygems_org}]
 
-    ui = Gem::MockGemUi.new "n"
-
-    use_ui ui do
-      assert_raise Gem::MockGemUi::TermError do
-        @cmd.execute
-      end
+    use_ui @ui do
+      @cmd.execute
     end
 
-    assert_equal [@gem_repo], Gem.sources
+    assert_equal [@gem_repo, https_rubygems_org], Gem.sources
 
     expected = <<-EXPECTED
+#{https_rubygems_org} added to sources
     EXPECTED
 
     assert_equal expected, @ui.output
@@ -629,17 +627,14 @@ def test_execute_append_https_rubygems_org
 
     @cmd.handle_options %W[--append #{https_rubygems_org}]
 
-    ui = Gem::MockGemUi.new "n"
-
-    use_ui ui do
-      assert_raise Gem::MockGemUi::TermError do
-        @cmd.execute
-      end
+    use_ui @ui do
+      @cmd.execute
     end
 
-    assert_equal [@gem_repo], Gem.sources
+    assert_equal [@gem_repo, https_rubygems_org], Gem.sources
 
     expected = <<-EXPECTED
+#{https_rubygems_org} added to sources
     EXPECTED
 
     assert_equal expected, @ui.output
@@ -872,6 +867,31 @@ def test_execute_remove_redundant_source_trailing_slash
     Gem.configuration.sources = nil
   end
 
+  def test_execute_remove_without_trailing_slash
+    source_uri = "https://rubygems.pkg.github.com/my-org/"
+
+    Gem.configuration.sources = [source_uri]
+
+    setup_fake_source(source_uri)
+
+    @cmd.handle_options %W[--remove https://rubygems.pkg.github.com/my-org]
+
+    use_ui @ui do
+      @cmd.execute
+    end
+
+    assert_equal [], Gem.sources
+
+    expected = <<-EOF
+#{source_uri} removed from sources
+    EOF
+
+    assert_equal expected, @ui.output
+    assert_equal "", @ui.error
+  ensure
+    Gem.configuration.sources = nil
+  end
+
   def test_execute_update
     @cmd.handle_options %w[--update]
 
@@ -982,6 +1002,6 @@ def setup_fake_source(uri)
       Marshal.dump specs, io
     end
 
-    @fetcher.data["#{uri}/specs.#{@marshal_version}.gz"] = specs_dump_gz.string
+    @fetcher.data["#{uri.chomp("/")}/specs.#{@marshal_version}.gz"] = specs_dump_gz.string
   end
 end