Fall back to raw HTML when HTML-to-Markdown conversion fails

Catches InvalidArgumentException from league/html-to-markdown's
HtmlConverter::convert() in convert_content() and falls back to the
post's raw HTML, so a single unparseable post no longer aborts the
entire export with 'Jekyll Export failed: Invalid HTML was provided'.

Bumps version to 4.0.3.

Fixes #400

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: benbalter

docs/changelog.md

@@ -1,5 +1,9 @@
 ## Changelog
 
+### 4.0.3
+
+* Catch `InvalidArgumentException` from `league/html-to-markdown` in `convert_content()` and fall back to the post's raw HTML for that single post instead of aborting the entire export with "Jekyll Export failed: Invalid HTML was provided" ([#400](https://github.com/benbalter/wordpress-static-site-exporter/issues/400))
+
 ### 4.0.2
 
 * Add shutdown handler to surface fatal errors (memory exhaustion, max execution time) during export with actionable error messages instead of a generic WordPress critical error page

docs/header.md

@@ -4,7 +4,7 @@ Tags: jekyll, github, github pages, yaml, export, markdown
 Requires at least: 6.4
 Tested up to: 6.9
 Requires PHP: 8.2
-Stable tag: 4.0.2
+Stable tag: 4.0.3
 License: GPLv3 or later
 License URI: http://www.gnu.org/licenses/gpl-3.0.html
 GitHub Plugin URI: benbalter/wordpress-to-jekyll-exporter

jekyll-exporter.php

@@ -12,7 +12,7 @@
  * Plugin Name: Static Site Exporter
  * Plugin URI:  https://github.com/benbalter/wordpress-to-jekyll-exporter/
  * Description: One-click plugin that converts all posts, pages, taxonomies, metadata, and settings to Markdown and YAML for Jekyll, Hugo, or other static site generators.
- * Version:     4.0.2
+ * Version:     4.0.3
  * Author:      Ben Balter
  * Author URI:  https://ben.balter.com
  * Text Domain: jekyll-exporter
@@ -377,7 +377,19 @@ public function convert_content( $post ) {
 			$converter->getEnvironment()->addConverter( new ColspanTableConverter() );
 		}
 
-		$markdown = $converter->convert( $content );
+		try {
+			$markdown = $converter->convert( $content );
+		} catch ( \InvalidArgumentException $e ) {
+			// Converter rejected the HTML (e.g., empty or unparseable content).
+			// Fall back to the raw HTML rather than aborting the entire export.
+			// See https://github.com/benbalter/wordpress-static-site-exporter/issues/400.
+			$post_id = isset( $post->ID ) ? (int) $post->ID : 0;
+			// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log
+			error_log( sprintf( '[jekyll-export] HTML-to-Markdown conversion failed for post %d: %s. Falling back to raw HTML.', $post_id, $e->getMessage() ) );
+			$content = apply_filters( 'jekyll_export_html', $content );
+			$content = apply_filters( 'jekyll_export_content', $content );
+			return $content;
+		}
 
 		if ( strpos( $markdown, '[]: ' ) !== false ) {
 			// faulty links; return plain HTML.

readme.txt

@@ -4,7 +4,7 @@ Tags: jekyll, github, github pages, yaml, export, markdown
 Requires at least: 6.4
 Tested up to: 6.9
 Requires PHP: 8.2
-Stable tag: 4.0.2
+Stable tag: 4.0.3
 License: GPLv3 or later
 License URI: http://www.gnu.org/licenses/gpl-3.0.html
 GitHub Plugin URI: benbalter/wordpress-to-jekyll-exporter
@@ -272,6 +272,10 @@ The custom post type will be exported as a Jekyll collection. You'll need to ini
 
 == Changelog ==
 
+= 4.0.3 =
+
+* Catch `InvalidArgumentException` from `league/html-to-markdown` in `convert_content()` and fall back to the post's raw HTML for that single post instead of aborting the entire export with "Jekyll Export failed: Invalid HTML was provided" ([#400](https://github.com/benbalter/wordpress-static-site-exporter/issues/400))
+
 = 4.0.2 =
 
 * Add shutdown handler to surface fatal errors (memory exhaustion, max execution time) during export with actionable error messages instead of a generic WordPress critical error page