[FIX] make heading level dynamic

The heading level of markdown documents is not strictly 1 based.
Some documents are starting with a random heading. Before those
documents were rendered empty. This change fixes that behavior,
headings to not longer start at level 1.

(cherry picked from commit 561af1b)

Author: jaapio

packages/guides/src/Compiler/NodeTransformers/SectionCreationTransformer.php

@@ -31,10 +31,12 @@ final class SectionCreationTransformer implements NodeTransformer
 {
     /** @var SectionNode[] $sectionStack */
     private array $sectionStack = [];
+    private int $firstLevel = 1;
 
     public function enterNode(Node $node, CompilerContextInterface $compilerContext): Node
     {
         if ($node instanceof DocumentNode) {
+            $this->firstLevel = 1;
             $this->sectionStack = [];
         }
 
@@ -68,7 +70,7 @@ public function leaveNode(Node $node, CompilerContextInterface $compilerContext)
 
         if (count($this->sectionStack) > 0 && $compilerContext->getShadowTree()->isLastChildOfParent()) {
             $lastSection = end($this->sectionStack);
-            while ($lastSection?->getTitle()->getLevel() > 1) {
+            while ($lastSection?->getTitle()->getLevel() > $this->firstLevel) {
                 $lastSection = array_pop($this->sectionStack);
             }
 
@@ -92,17 +94,17 @@ public function leaveNode(Node $node, CompilerContextInterface $compilerContext)
                 end($this->sectionStack)->addChildNode($newSection);
             }
 
-            $this->sectionStack[] = $newSection;
+            $this->pushNewSectionToStack($newSection);
 
-            return $lastSection?->getTitle()->getLevel() === 1 ? $lastSection : null;
+            return $lastSection?->getTitle()->getLevel() <= $this->firstLevel ? $lastSection : null;
         }
 
         $newSection = new SectionNode($node);
         if ($lastSection instanceof SectionNode) {
             $lastSection->addChildNode($newSection);
         }
 
-        $this->sectionStack[] = $newSection;
+        $this->pushNewSectionToStack($newSection);
 
         return null;
     }
@@ -117,4 +119,21 @@ public function getPriority(): int
         // Should run as first transformer
         return PHP_INT_MAX;
     }
+
+    /**
+     * Pushes the new section to the stack.
+     *
+     * The stack is used to track the current level of nodes and adding child
+     * nodes to the section. As not all documentation formats are using the
+     * correct level of title nodes we need to track the level of the first
+     * title node to determine the correct level of the section.
+     */
+    private function pushNewSectionToStack(SectionNode $newSection): void
+    {
+        if (count($this->sectionStack) === 0) {
+            $this->firstLevel = $newSection->getTitle()->getLevel();
+        }
+
+        $this->sectionStack[] = $newSection;
+    }
 }

packages/guides/src/Nodes/DocumentNode.php

@@ -121,7 +121,7 @@ public function getPageTitle(): string|null
     public function getTitle(): TitleNode|null
     {
         foreach ($this->value as $node) {
-            if ($node instanceof SectionNode && $node->getTitle()->getLevel() === 1) {
+            if ($node instanceof SectionNode) {
                 return $node->getTitle();
             }
 

tests/Integration/tests/markdown/sections-no-level-1-md/expected/index.html

@@ -0,0 +1,45 @@
+<!-- content start -->
+
+<div class="section" id="introduction">
+            <h2>Introduction</h2>
+
+    <p>This is a sample Markdown document demonstrating sections and subsections.</p>
+
+    </div>
+            <div class="section" id="section-1">
+            <h2>Section 1</h2>
+
+    <p>This is the first section of the document.</p>
+
+            <div class="section" id="subsection-1-1">
+            <h3>Subsection 1.1</h3>
+
+    <p>This is a subsection under Section 1.</p>
+
+    </div>
+            <div class="section" id="subsection-1-2">
+            <h3>Subsection 1.2</h3>
+
+    <p>Another subsection under Section 1.</p>
+
+    </div>
+    </div>
+            <div class="section" id="section-2">
+            <h2>Section 2</h2>
+
+    <p>Moving on to the second section of the document.</p>
+
+            <div class="section" id="subsection-2-1">
+            <h3>Subsection 2.1</h3>
+
+    <p>A subsection under Section 2.</p>
+
+    </div>
+    </div>
+            <div class="section" id="conclusion">
+            <h2>Conclusion</h2>
+
+    <p>In conclusion, this is a simple example of a Markdown document with various sections and subsections.</p>
+
+    </div>
+<!-- content end -->

tests/Integration/tests/markdown/sections-no-level-1-md/input/guides.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<guides xmlns="https://www.phpdoc.org/guides"
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:schemaLocation="https://www.phpdoc.org/guides packages/guides-cli/resources/schema/guides.xsd"
+        input-format="md"
+>
+</guides>

tests/Integration/tests/markdown/sections-no-level-1-md/input/index.md

@@ -0,0 +1,27 @@
+## Introduction
+
+This is a sample Markdown document demonstrating sections and subsections.
+
+## Section 1
+
+This is the first section of the document.
+
+### Subsection 1.1
+
+This is a subsection under Section 1.
+
+### Subsection 1.2
+
+Another subsection under Section 1.
+
+## Section 2
+
+Moving on to the second section of the document.
+
+### Subsection 2.1
+
+A subsection under Section 2.
+
+## Conclusion
+
+In conclusion, this is a simple example of a Markdown document with various sections and subsections.