Fix duplicate responses in XPath following, following-sibling, preceding, preceding-sibling (#255)

naitoh · web-flow · commit 249d770b4ead · 2025-05-06T21:33:00.000+09:00
## Why? See: #251 (comment) ## Expected values - XPath : a/d/preceding::* => ["d", "c", "b"] ```xml <a> <b/>  <c/>  <d/>  <d/>  <e/> <f/> </a> ``` - XPath : a/d/following::* => ["d", "e", "f"] ```xml <a> <b/> <c/> <d/>  <d/>  <e/>  <f/>  </a> ``` - XPath : a/b/x/following-sibling:* => ["c", "d", "e"] ```xml <a> <b> <x/>  <c/>  <d/>  </b> <b> <x/>  <e/>  </b> </a> ``` - XPath : a/b/x/following-sibling:* => ["c", "d", "x", "e"] ```xml <a> <b> <x/>  <c/>  <d/>  <x/>  <e/>  </b> </a> ``` - XPath : a/b/x/preceding-sibling::* => ["e", "d", "c"] ```xml <a> <b> <c/>  <d/>  <x/>  </b> <b> <e/>  <x/>  </b> </a> ``` - XPath : a/b/x/preceding-sibling::* => ["e", "x", "d", "c"] ```xml <a> <b> <c/>  <d/>  <x/>  <e/>  <x/>  </b> </a> ``` - XPath : //a/following-sibling:*[1] => ["w", "x", "y", "z"] ```xml <div> <div> <a/> <-- self --> <w/> <-- //a/following-sibling:*[1] --> </div> <a/> <-- self --> <x/> <-- //a/following-sibling:*[1] --> <a/> <-- self --> <y/> <-- //a/following-sibling:*[1] --> <a/> <-- self --> <z/> <-- //a/following-sibling:*[1] --> </div> ```
diff --git a/lib/rexml/xpath_parser.rb b/lib/rexml/xpath_parser.rb
@@ -144,7 +144,7 @@ def match(path_stack, nodeset)
       result = expr(path_stack, nodeset)
       case result
       when Array # nodeset
-        unnode(result)
+        unnode(result).uniq
       else
         [result]
       end
diff --git a/test/xpath/test_base.rb b/test/xpath/test_base.rb
@@ -416,12 +416,103 @@ def test_preceding
       assert_equal( 4, cs.length )
     end
 
-    def test_preceding_sibling
-      d = REXML::Document.new("<a><b><c/><d/><x/></b><b><e/><x/></b></a>")
-      matches = REXML::XPath.match(d, "a/b/x/preceding-sibling::node()")
+    def test_preceding_multiple
+      source = <<-XML
+<a>
+  <b/><c/><d/><d/><e/><f/>
+</a>
+      XML
+      doc = REXML::Document.new(source)
+      matches = REXML::XPath.match(doc, "a/d/preceding::*")
+      assert_equal(["d", "c", "b"], matches.map(&:name))
+    end
+
+    def test_following_multiple
+      source = <<-XML
+<a>
+  <b/><c/><d/><d/><e/><f/>
+</a>
+      XML
+      doc = REXML::Document.new(source)
+      matches = REXML::XPath.match(doc, "a/d/following::*")
+      assert_equal(["d", "e", "f"], matches.map(&:name))
+    end
+
+    def test_following_sibling_across_multiple_nodes
+      source = <<-XML
+<a>
+  <b>
+    <x/><c/><d/>
+  </b>
+  <b>
+    <x/><e/>
+  </b>
+</a>
+      XML
+      doc = REXML::Document.new(source)
+      matches = REXML::XPath.match(doc, "a/b/x/following-sibling::*")
+      assert_equal(["c", "d", "e"], matches.map(&:name))
+    end
+
+    def test_following_sibling_within_single_node
+      source = <<-XML
+<a>
+  <b>
+    <x/><c/><d/><x/><e/>
+  </b>
+</a>
+      XML
+      doc = REXML::Document.new(source)
+      matches = REXML::XPath.match(doc, "a/b/x/following-sibling::*")
+      assert_equal(["c", "d", "x", "e"], matches.map(&:name))
+    end
+
+    def test_following_sibling_predicates
+      source = <<-XML
+<div>
+  <div>
+    <a/><w/>
+  </div>
+  <a/><x/>
+  <a/><y/>
+  <a/><z/>
+</div>
+      XML
+      doc = REXML::Document.new(source)
+      # Finds a node flowing <a/>
+      matches = REXML::XPath.match(doc, "//a/following-sibling::*[1]")
+      assert_equal(["w", "x", "y", "z"], matches.map(&:name))
+    end
+
+    def test_preceding_sibling_across_multiple_nodes
+      source = <<-XML
+<a>
+  <b>
+    <c/><d/><x/>
+  </b>
+  <b>
+    <e/><x/>
+  </b>
+</a>
+      XML
+      doc = REXML::Document.new(source)
+      matches = REXML::XPath.match(doc, "a/b/x/preceding-sibling::*")
       assert_equal(["e", "d", "c"], matches.map(&:name))
     end
 
+    def test_preceding_sibling_within_single_node
+      source = <<-XML
+<a>
+  <b>
+    <c/><d/><x/><e/><x/>
+  </b>
+</a>
+      XML
+      doc = REXML::Document.new(source)
+      matches = REXML::XPath.match(doc, "a/b/x/preceding-sibling::*")
+      assert_equal(["e", "x", "d", "c"], matches.map(&:name))
+    end
+
     def test_following
       d = Document.new "<a><b id='0'/><b/><b><c id='1'/><c id='2'/></b><b id='1'/></a>"
       start = XPath.first( d, "/a/b[@id='0']" )
