Tighten RBS test suite: consolidate redundant variants, strengthen weak assertions

Six edits driven by a focused review of the PR's 44 added tests:

* Drop test_method_without_type_signature — pure default-state check that
  was redundant with every other parser test using a sig-less sibling.
* Drop test_merge_rbs_signatures_unmatched_key — exercised built-in Hash
  semantics rather than store behavior.
* Replace six per-type-form tests (union/optional/tuple/intersection/proc/
  block) with one data-driven test that iterates the same six shapes. Same
  coverage, ~50 fewer lines.
* Strengthen test_signature_to_html_multiline — previously asserted only
  that a newline appeared somewhere; now asserts ordered structure of each
  rendered line.
* Strengthen test_type_signature_invalid_still_stored_and_warns — asserts
  the parser emits the documented "invalid RBS type signature" warning
  in addition to keeping the malformed sig.
* Re-target test_merge_rbs_signatures_clears_signatures_removed_in_subsequent_merge
  (formerly _replaces_previous_rbs_signature) to verify that a key
  REMOVED in a later merge clears the signature — the actual property
  clear_rbs_signatures was added for.

Net: 44 PR-added tests -> 37, same or stronger coverage.

Author: st0012

test/rdoc/parser/ruby_test.rb

@@ -2696,20 +2696,6 @@ def convert(value); end
     assert_equal 'Convert a value', convert.comment.text.strip
   end
 
-  def test_method_without_type_signature
-    util_parser <<~RUBY
-      class Foo
-        # A plain method
-        def plain; end
-      end
-    RUBY
-
-    klass = @store.find_class_named 'Foo'
-    plain = klass.method_list.first
-    assert_nil plain.type_signature_lines
-    assert_equal 'A plain method', plain.comment.text.strip
-  end
-
   def test_method_type_signature_with_blank_line_separation
     util_parser <<~RUBY
       class Foo
@@ -2726,18 +2712,24 @@ def bar(x); end
     assert_equal "Documentation here", bar.comment.text
   end
 
-  def test_type_signature_invalid_still_stored
-    util_parser <<~RUBY
-      class Foo
-        #: (String ->
-        def bar(x); end
-      end
-    RUBY
+  def test_type_signature_invalid_still_stored_and_warns
+    @options.verbosity = 2
+    _out, err = capture_output do
+      util_parser <<~RUBY
+        class Foo
+          #: (String ->
+          def bar(x); end
+        end
+      RUBY
+    end
 
     klass = @store.find_class_named 'Foo'
     bar = klass.method_list.first
-    # Invalid sigs are still stored (don't block display)
+    # Invalid sigs are still stored so the doc author can see what they typed.
     assert_equal ['(String ->'], bar.type_signature_lines
+    # ...but a warning must be emitted so it doesn't slip through silently.
+    # The format includes the file and line so authors can find the typo.
+    assert_match %r{:\d+: invalid RBS type signature: "\(String ->"}, err
   end
 
   def util_parser(content)

test/rdoc/rbs_helper_test.rb

@@ -97,56 +97,34 @@ def test_signature_to_html_multiline
     lookup = { 'String' => 'String.html', 'Integer' => 'Integer.html' }
     result = RDoc::RbsHelper.signature_to_html(["(String) -> Integer", "(Integer) -> String"], lookup: lookup, from_path: 'Test.html')
 
-    assert_includes result, '<a href="String.html" class="rbs-type">String</a>'
-    assert_includes result, '<a href="Integer.html" class="rbs-type">Integer</a>'
-    assert_includes result, "\n"
-  end
-
-  def test_signature_to_html_union_type
-    lookup = { 'String' => 'String.html', 'Integer' => 'Integer.html' }
-    result = RDoc::RbsHelper.signature_to_html(["(String | Integer) -> void"], lookup: lookup, from_path: 'Test.html')
-
-    assert_includes result, '<a href="String.html" class="rbs-type">String</a>'
-    assert_includes result, '<a href="Integer.html" class="rbs-type">Integer</a>'
-  end
-
-  def test_signature_to_html_optional_type
-    lookup = { 'String' => 'String.html' }
-    result = RDoc::RbsHelper.signature_to_html(["String?"], lookup: lookup, from_path: 'Test.html')
-
-    assert_includes result, '<a href="String.html" class="rbs-type">String</a>'
-  end
-
-  def test_signature_to_html_tuple_type
-    lookup = { 'String' => 'String.html', 'Integer' => 'Integer.html' }
-    result = RDoc::RbsHelper.signature_to_html(["[String, Integer]"], lookup: lookup, from_path: 'Test.html')
-
-    assert_includes result, '<a href="String.html" class="rbs-type">String</a>'
-    assert_includes result, '<a href="Integer.html" class="rbs-type">Integer</a>'
-  end
-
-  def test_signature_to_html_intersection_type
-    lookup = { 'String' => 'String.html', 'Comparable' => 'Comparable.html' }
-    result = RDoc::RbsHelper.signature_to_html(["(String & Comparable) -> void"], lookup: lookup, from_path: 'Test.html')
-
-    assert_includes result, '<a href="String.html" class="rbs-type">String</a>'
-    assert_includes result, '<a href="Comparable.html" class="rbs-type">Comparable</a>'
-  end
-
-  def test_signature_to_html_proc_type
-    lookup = { 'String' => 'String.html', 'Integer' => 'Integer.html' }
-    result = RDoc::RbsHelper.signature_to_html(["^(String) -> Integer"], lookup: lookup, from_path: 'Test.html')
-
-    assert_includes result, '<a href="String.html" class="rbs-type">String</a>'
-    assert_includes result, '<a href="Integer.html" class="rbs-type">Integer</a>'
-  end
-
-  def test_signature_to_html_links_block_return_type
-    lookup = { 'String' => 'String.html', 'Integer' => 'Integer.html' }
-    result = RDoc::RbsHelper.signature_to_html(["() { (String) -> Integer } -> void"], lookup: lookup, from_path: 'Test.html')
-
-    assert_includes result, '<a href="String.html" class="rbs-type">String</a>'
-    assert_includes result, '<a href="Integer.html" class="rbs-type">Integer</a>'
+    first, second = result.split("\n", 2)
+    assert_match %r{<a href="String\.html"[^>]*>String</a>.*&rarr;.*<a href="Integer\.html"[^>]*>Integer</a>}, first
+    assert_match %r{<a href="Integer\.html"[^>]*>Integer</a>.*&rarr;.*<a href="String\.html"[^>]*>String</a>}, second
+  end
+
+  def test_signature_to_html_links_types_inside_compound_forms
+    lookup = {
+      'String'     => 'String.html',
+      'Integer'    => 'Integer.html',
+      'Comparable' => 'Comparable.html',
+    }
+
+    cases = [
+      ['union',        "(String | Integer) -> void",        %w[String Integer]],
+      ['optional',     "String?",                           %w[String]],
+      ['tuple',        "[String, Integer]",                 %w[String Integer]],
+      ['intersection', "(String & Comparable) -> void",     %w[String Comparable]],
+      ['proc',         "^(String) -> Integer",              %w[String Integer]],
+      ['block',        "() { (String) -> Integer } -> void", %w[String Integer]],
+    ]
+
+    cases.each do |form, sig, expected_types|
+      result = RDoc::RbsHelper.signature_to_html([sig], lookup: lookup, from_path: 'Test.html')
+      expected_types.each do |type|
+        assert_includes result, %(<a href="#{lookup[type]}" class="rbs-type">#{type}</a>),
+          "#{form} signature #{sig.inspect} did not link #{type}"
+      end
+    end
   end
 
   def test_signature_to_html_unparseable_signature

test/rdoc/rdoc_store_test.rb

@@ -1326,16 +1326,16 @@ def test_merge_rbs_signatures_constructor
     assert_equal ['(String name) -> void'], ctor.type_signature_lines
   end
 
-  def test_merge_rbs_signatures_replaces_previous_rbs_signature
+  def test_merge_rbs_signatures_clears_signatures_removed_in_subsequent_merge
     @s.merge_rbs_signatures(
       'Object#method' => ['() -> String']
     )
+    assert_equal ['() -> String'], @meth.type_signature_lines
 
-    @s.merge_rbs_signatures(
-      'Object#method' => ['() -> Integer']
-    )
-
-    assert_equal ['() -> Integer'], @meth.type_signature_lines
+    # Subsequent merge no longer mentions the key — the signature must be
+    # cleared rather than left stale, so live-reload reflects deletions.
+    @s.merge_rbs_signatures({})
+    assert_nil @meth.type_signature_lines
   end
 
   def test_merge_rbs_signatures_propagates_to_method_alias
@@ -1447,15 +1447,4 @@ def test_merge_rbs_signatures_does_not_overwrite_inline_annotations
     assert_equal ['(String) -> void'], m.type_signature_lines
   end
 
-  def test_merge_rbs_signatures_unmatched_key
-    @s.merge_rbs_signatures(
-      'Object#nonexistent' => ['(String) -> void']
-    )
-
-    # No method matches — nothing should blow up, no sigs assigned
-    @klass.method_list.each do |m|
-      assert_nil m.type_signature_lines
-    end
-  end
-
 end