bug(#221): empty-object allows void attributes

src/main/resources/org/eolang/lints/errors/empty-object.xsl

@@ -2,7 +2,7 @@
 <!--
 The MIT License (MIT)
 
-Copyright (c) 2016-2024 Objectionary.com
+Copyright (c) 2016-2025 Objectionary.com
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -28,7 +28,7 @@ SOFTWARE.
   <xsl:output encoding="UTF-8" method="xml"/>
   <xsl:template match="/">
     <defects>
-      <xsl:for-each select="/program/objects//o[not(o)]">
+      <xsl:for-each select="/program/objects//o[not(@base) and not(o) and not(@atom)]">
         <xsl:element name="defect">
           <xsl:attribute name="line">
             <xsl:value-of select="eo:lineno(@line)"/>

src/test/resources/org/eolang/lints/packs/empty-object/allows-good-objects-with-multiple-void-attributes.yaml

@@ -0,0 +1,41 @@
+# The MIT License (MIT)
+#
+# Copyright (c) 2016-2025 Objectionary.com
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+---
+sheets:
+  - /org/eolang/lints/errors/empty-object.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=0]
+document: |
+  <program>
+    <objects>
+      <o line="2" name="main" pos="0">
+         <o base="∅" line="2" name="x" pos="1"/>
+         <o base="∅" line="2" name="y" pos="1"/>
+         <o base=".print" line="3" name="@" pos="2">
+            <o base="stdout" line="4" pos="4">
+               <o base="string" line="4" pos="11">48-65-6C-6C-6F-21</o>
+               <o base="x" line="4" pos="20"/>
+            </o>
+         </o>
+      </o>
+    </objects>
+  </program>

src/test/resources/org/eolang/lints/packs/empty-object/allows-good-objects.yaml

@@ -0,0 +1,40 @@
+# The MIT License (MIT)
+#
+# Copyright (c) 2016-2025 Objectionary.com
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+---
+sheets:
+  - /org/eolang/lints/errors/empty-object.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=0]
+document: |
+  <program>
+    <objects>
+      <o line="2" name="main" pos="0">
+         <o base="∅" line="2" name="x" pos="1"/>
+         <o base=".print" line="3" name="@" pos="2">
+            <o base="stdout" line="4" pos="4">
+               <o base="string" line="4" pos="11">48-65-6C-6C-6F-21</o>
+               <o base="x" line="4" pos="20"/>
+            </o>
+         </o>
+      </o>
+    </objects>
+  </program>

src/test/resources/org/eolang/lints/packs/empty-object/allows-void-attributes.yaml

@@ -0,0 +1,34 @@
+# The MIT License (MIT)
+#
+# Copyright (c) 2016-2025 Objectionary.com
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+---
+sheets:
+  - /org/eolang/lints/errors/empty-object.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=0]
+document: |
+  <program>
+    <objects>
+        <o line="2" name="main" pos="0">
+           <o base="∅" line="2" name="x" pos="1"/>
+        </o>
+     </objects>
+  </program>

src/test/resources/org/eolang/lints/packs/empty-object/catches-empty-object-that-is-not-void-attribute.yaml

@@ -0,0 +1,41 @@
+# The MIT License (MIT)
+#
+# Copyright (c) 2016-2025 Objectionary.com
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+---
+sheets:
+  - /org/eolang/lints/errors/empty-object.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=1]
+  - /defects/defect[@line='4']
+document: |
+  <program>
+    <objects>
+      <o line="2" name="main" pos="0">
+         <o base="∅" line="2" name="x" pos="1"/>
+         <o base=".print" line="3" name="@" pos="2">
+            <o base="stdout" line="4" pos="4">
+               <o base="string" line="4" pos="11">48-65-6C-6C-6F-21</o>
+               <o name="y" line="4" pos="20"/>
+            </o>
+         </o>
+      </o>
+    </objects>
+  </program>

src/test/resources/org/eolang/lints/packs/empty-object/catches-empty-object.yaml

@@ -1,6 +1,6 @@
 # The MIT License (MIT)
 #
-# Copyright (c) 2016-2024 Objectionary.com
+# Copyright (c) 2016-2025 Objectionary.com
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal

src/test/resources/org/eolang/lints/packs/empty-object/catches-empty-objects-in-snippet.yaml

@@ -0,0 +1,37 @@
+# The MIT License (MIT)
+#
+# Copyright (c) 2016-2025 Objectionary.com
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+---
+sheets:
+  - /org/eolang/lints/errors/empty-object.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=1]
+  - /defects/defect[@line='3']
+input: |
+  # Snippet with some empty objects.
+  [] > app
+    [] > a1
+    if. > @
+      true
+      []
+        2 > @
+      1
+    [x] > a2

src/test/resources/org/eolang/lints/packs/empty-object/catches-empty-with-weird-line.yaml

@@ -1,6 +1,6 @@
 # The MIT License (MIT)
 #
-# Copyright (c) 2016-2024 Objectionary.com
+# Copyright (c) 2016-2025 Objectionary.com
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal