From 71da9bff818c0b2e850c0bed3125544987a093ec Mon Sep 17 00:00:00 2001
From: Marat-Tim <rurikcat@gmail.com>
Date: Sat, 3 May 2025 14:52:32 +0300
Subject: [PATCH 1/3] feat(#256): lint that find not merged bases

---
 .../eolang/lints/refs/base-must-be-merged.xsl | 37 +++++++++++
 .../motives/refs/base-must-be-merged.md       | 61 +++++++++++++++++++
 .../catches-not-merged-objects.yaml           | 16 +++++
 .../no-merge-if-base-starts-with-dot.yaml     | 13 ++++
 .../no-merge-if-object-has-data.yaml          | 15 +++++
 .../no-merge-if-object-is-abstract.yaml       | 13 ++++
 ...ge-if-parent-base-not-starts-with-dot.yaml | 13 ++++
 .../prints-name-of-not-merged-object.yaml     | 15 +++++
 8 files changed, 183 insertions(+)
 create mode 100644 src/main/resources/org/eolang/lints/refs/base-must-be-merged.xsl
 create mode 100644 src/main/resources/org/eolang/motives/refs/base-must-be-merged.md
 create mode 100644 src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/catches-not-merged-objects.yaml
 create mode 100644 src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-base-starts-with-dot.yaml
 create mode 100644 src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-has-data.yaml
 create mode 100644 src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-is-abstract.yaml
 create mode 100644 src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-parent-base-not-starts-with-dot.yaml
 create mode 100644 src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/prints-name-of-not-merged-object.yaml

diff --git a/src/main/resources/org/eolang/lints/refs/base-must-be-merged.xsl b/src/main/resources/org/eolang/lints/refs/base-must-be-merged.xsl
new file mode 100644
index 000000000..3a30a8e44
--- /dev/null
+++ b/src/main/resources/org/eolang/lints/refs/base-must-be-merged.xsl
@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
+  ~ SPDX-License-Identifier: MIT
+  -->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:eo="https://www.eolang.org" id="base-must-be-merged" version="2.0">
+  <xsl:import href="/org/eolang/parser/_funcs.xsl"/>
+  <xsl:import href="/org/eolang/funcs/lineno.xsl"/>
+  <xsl:import href="/org/eolang/funcs/defect-context.xsl"/>
+  <xsl:output encoding="UTF-8" method="xml"/>
+  <xsl:template match="/">
+    <defects>
+      <xsl:for-each select="//o[not(eo:abstract(.)) and parent::o[starts-with(@base, '.')] and not(starts-with(@base, '.')) and not(text())]">
+        <defect>
+          <xsl:variable name="line" select="eo:lineno(@line)"/>
+          <xsl:attribute name="line">
+            <xsl:value-of select="$line"/>
+          </xsl:attribute>
+          <xsl:if test="$line = '0'">
+            <xsl:attribute name="context">
+              <xsl:value-of select="eo:defect-context(.)"/>
+            </xsl:attribute>
+          </xsl:if>
+          <xsl:attribute name="severity">
+            <xsl:text>warning</xsl:text>
+          </xsl:attribute>
+          <xsl:text>Object </xsl:text>
+          <xsl:if test="@name">
+            <xsl:value-of select="@name"/>
+            <xsl:text> </xsl:text>
+          </xsl:if>
+          <xsl:text>can be merged with its parent</xsl:text>
+        </defect>
+      </xsl:for-each>
+    </defects>
+  </xsl:template>
+</xsl:stylesheet>
diff --git a/src/main/resources/org/eolang/motives/refs/base-must-be-merged.md b/src/main/resources/org/eolang/motives/refs/base-must-be-merged.md
new file mode 100644
index 000000000..583ec88ae
--- /dev/null
+++ b/src/main/resources/org/eolang/motives/refs/base-must-be-merged.md
@@ -0,0 +1,61 @@
+# '@base' attributes of objects must be merged if possible
+
+In [XMIR], the object must be merged with parent if the following
+conditions are met:
+
+1. Object is not abstract
+2. Attribute `@base` of parent object should start with dot
+3. Attribute `@base` object should not start with dot
+4. Object should not have data
+
+Incorrect:
+
+```xml
+<o base=".foo">
+    <o base=".bar">
+        <o base="x"/>
+    </o>
+</o>
+```
+
+Correct:
+
+```xml
+<o base="x.bar.foo"/>
+```
+
+Correct:
+
+```xml
+<o base=".foo">
+    <o base=".bar"/>
+</o>
+```
+
+Correct:
+
+```xml
+<o base=".foo">
+    <o/>
+</o>
+```
+
+Correct:
+
+```xml
+<o base=".foo">
+    <o base="bar">
+        A1-B2-C3-D4-E5
+    </o>
+</o>
+```
+
+Correct:
+
+```xml
+<o base="foo">
+    <o base=".bar"/>
+</o>
+```
+
+[XMIR]: https://news.eolang.org/2022-11-25-xmir-guide.html
diff --git a/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/catches-not-merged-objects.yaml b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/catches-not-merged-objects.yaml
new file mode 100644
index 000000000..d39df581a
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/catches-not-merged-objects.yaml
@@ -0,0 +1,16 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/refs/base-must-be-merged.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=1]
+  - /defects/defect[@line='2']
+document: |
+  <object>
+    <o base=".foo">
+      <o base=".bar">
+        <o base="x" line="2"/>
+      </o>
+    </o>
+  </object>
diff --git a/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-base-starts-with-dot.yaml b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-base-starts-with-dot.yaml
new file mode 100644
index 000000000..870658d9a
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-base-starts-with-dot.yaml
@@ -0,0 +1,13 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/refs/base-must-be-merged.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=0]
+document: |
+  <object>
+    <o base=".foo">
+      <o base=".bar"/>
+    </o>
+  </object>
diff --git a/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-has-data.yaml b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-has-data.yaml
new file mode 100644
index 000000000..cfc7653f1
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-has-data.yaml
@@ -0,0 +1,15 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/refs/base-must-be-merged.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=0]
+document: |
+  <object>
+    <o base=".foo">
+      <o base="bar">
+       A1-B2-C3-D4-E5
+      </o>
+    </o>
+  </object>
diff --git a/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-is-abstract.yaml b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-is-abstract.yaml
new file mode 100644
index 000000000..fe8433d23
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-is-abstract.yaml
@@ -0,0 +1,13 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/refs/base-must-be-merged.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=0]
+document: |
+  <object>
+    <o base=".foo">
+      <o/>
+    </o>
+  </object>
diff --git a/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-parent-base-not-starts-with-dot.yaml b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-parent-base-not-starts-with-dot.yaml
new file mode 100644
index 000000000..2a9a2667e
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-parent-base-not-starts-with-dot.yaml
@@ -0,0 +1,13 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/refs/base-must-be-merged.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=0]
+document: |
+  <object>
+    <o base="foo">
+      <o base=".bar"/>
+    </o>
+  </object>
diff --git a/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/prints-name-of-not-merged-object.yaml b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/prints-name-of-not-merged-object.yaml
new file mode 100644
index 000000000..b4f54d1f4
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/prints-name-of-not-merged-object.yaml
@@ -0,0 +1,15 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/refs/base-must-be-merged.xsl
+asserts:
+  - /defects/defect[contains(text(), 'abracadabra')]
+document: |
+  <object>
+    <o base=".foo">
+      <o base=".bar">
+        <o base="x" name="abracadabra"/>
+      </o>
+    </o>
+  </object>

From b7cb9846a174ec4ee2464d9c79ec620d4854dec8 Mon Sep 17 00:00:00 2001
From: Marat-Tim <rurikcat@gmail.com>
Date: Sat, 3 May 2025 15:18:20 +0300
Subject: [PATCH 2/3] feat(#256): delete impossible test

---
 ...no-merge-if-parent-base-not-starts-with-dot.yaml | 13 -------------
 1 file changed, 13 deletions(-)
 delete mode 100644 src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-parent-base-not-starts-with-dot.yaml

diff --git a/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-parent-base-not-starts-with-dot.yaml b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-parent-base-not-starts-with-dot.yaml
deleted file mode 100644
index 2a9a2667e..000000000
--- a/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-parent-base-not-starts-with-dot.yaml
+++ /dev/null
@@ -1,13 +0,0 @@
-# SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
-# SPDX-License-Identifier: MIT
----
-sheets:
-  - /org/eolang/lints/refs/base-must-be-merged.xsl
-asserts:
-  - /defects[count(defect[@severity='warning'])=0]
-document: |
-  <object>
-    <o base="foo">
-      <o base=".bar"/>
-    </o>
-  </object>

From 89a147f6e6c90a9a4827f45ca3c7fc24dc30d5b6 Mon Sep 17 00:00:00 2001
From: Marat-Tim <rurikcat@gmail.com>
Date: Mon, 5 May 2025 14:42:23 +0300
Subject: [PATCH 3/3] feat(256): check for inner objects

---
 .../eolang/lints/refs/base-must-be-merged.xsl |  3 ++-
 .../motives/refs/base-must-be-merged.md       | 23 +++++++++++--------
 .../no-merge-if-object-has-data.yaml          |  2 +-
 .../no-merge-if-object-has-inner-object.yaml  | 15 ++++++++++++
 4 files changed, 31 insertions(+), 12 deletions(-)
 create mode 100644 src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-has-inner-object.yaml

diff --git a/src/main/resources/org/eolang/lints/refs/base-must-be-merged.xsl b/src/main/resources/org/eolang/lints/refs/base-must-be-merged.xsl
index 3a30a8e44..684a99102 100644
--- a/src/main/resources/org/eolang/lints/refs/base-must-be-merged.xsl
+++ b/src/main/resources/org/eolang/lints/refs/base-must-be-merged.xsl
@@ -3,7 +3,7 @@
   ~ SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
   ~ SPDX-License-Identifier: MIT
   -->
-<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:eo="https://www.eolang.org" id="base-must-be-merged" version="2.0">
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:eo="https://www.eolang.org" id="base-must-be-merged" version="2.0">
   <xsl:import href="/org/eolang/parser/_funcs.xsl"/>
   <xsl:import href="/org/eolang/funcs/lineno.xsl"/>
   <xsl:import href="/org/eolang/funcs/defect-context.xsl"/>
@@ -11,6 +11,7 @@
   <xsl:template match="/">
     <defects>
       <xsl:for-each select="//o[not(eo:abstract(.)) and parent::o[starts-with(@base, '.')] and not(starts-with(@base, '.')) and not(text())]">
+        <xsl:message select="."/>
         <defect>
           <xsl:variable name="line" select="eo:lineno(@line)"/>
           <xsl:attribute name="line">
diff --git a/src/main/resources/org/eolang/motives/refs/base-must-be-merged.md b/src/main/resources/org/eolang/motives/refs/base-must-be-merged.md
index 583ec88ae..c5868aeeb 100644
--- a/src/main/resources/org/eolang/motives/refs/base-must-be-merged.md
+++ b/src/main/resources/org/eolang/motives/refs/base-must-be-merged.md
@@ -7,14 +7,15 @@ conditions are met:
 2. Attribute `@base` of parent object should start with dot
 3. Attribute `@base` object should not start with dot
 4. Object should not have data
+5. Object should not have inner objects
 
 Incorrect:
 
 ```xml
 <o base=".foo">
-    <o base=".bar">
-        <o base="x"/>
-    </o>
+  <o base=".bar">
+    <o base="x"/>
+  </o>
 </o>
 ```
 
@@ -28,7 +29,7 @@ Correct:
 
 ```xml
 <o base=".foo">
-    <o base=".bar"/>
+  <o base=".bar"/>
 </o>
 ```
 
@@ -36,7 +37,7 @@ Correct:
 
 ```xml
 <o base=".foo">
-    <o/>
+  <o/>
 </o>
 ```
 
@@ -44,17 +45,19 @@ Correct:
 
 ```xml
 <o base=".foo">
-    <o base="bar">
-        A1-B2-C3-D4-E5
-    </o>
+  <o base="bar">
+    A1-B2-C3-D4-E5
+  </o>
 </o>
 ```
 
 Correct:
 
 ```xml
-<o base="foo">
-    <o base=".bar"/>
+<o base=".foo">
+  <o base="bar">
+    <o base="baz"/>
+  </o>
 </o>
 ```
 
diff --git a/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-has-data.yaml b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-has-data.yaml
index cfc7653f1..9de923dc3 100644
--- a/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-has-data.yaml
+++ b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-has-data.yaml
@@ -9,7 +9,7 @@ document: |
   <object>
     <o base=".foo">
       <o base="bar">
-       A1-B2-C3-D4-E5
+        A1-B2-C3-D4-E5
       </o>
     </o>
   </object>
diff --git a/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-has-inner-object.yaml b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-has-inner-object.yaml
new file mode 100644
index 000000000..81abae977
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/base-must-be-merged/no-merge-if-object-has-inner-object.yaml
@@ -0,0 +1,15 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/refs/base-must-be-merged.xsl
+asserts:
+  - /defects[count(defect[@severity='warning'])=0]
+document: |
+  <object>
+    <o base=".foo">
+      <o base="bar">
+        <o base="baz"/>
+      </o>
+    </o>
+  </object>