Shortcodes: enable inline PDFs (#14960)

* Shortcodes: enable inline PDFs

* Fix sprintf replacement

* Add unit tests and fix lint errors

* Fix lint errors, add prefix, and other fixes

Add unit test

* Fix unit test

Co-authored-by: Jeremy Herve <jeremy@jeremy.hu>

modules/shortcodes/inline-pdfs.php

@@ -0,0 +1,30 @@
+<?php
+/**
+ * Embed support for Inline PDFs
+ *
+ * Takes a plain-text PDF URL (*.pdf), and attempts to embed it directly
+ * in the post instead of leaving it as a bare link.
+ *
+ * @package Jetpack
+ */
+
+wp_embed_register_handler( 'inline-pdfs', '#https?://[^<]*\.pdf$#i', 'jetpack_inline_pdf_embed_handler' );
+
+/**
+ * Callback to modify the output of embedded PDF files.
+ *
+ * @param array $matches Regex partial matches against the URL passed.
+ * @param array $attr    Attributes received in embed response.
+ * @param array $url     Requested URL to be embedded.
+ */
+function jetpack_inline_pdf_embed_handler( $matches, $attr, $url ) {
+	/** This action is documented in modules/widgets/social-media-icons.php */
+	do_action( 'jetpack_bump_stats_extras', 'embeds', 'inline-pdf' );
+
+	return sprintf(
+		'<object data="%1$s" type="application/pdf" width="100%%" height="800">
+		  <p><a href="%1$s">%1$s</a></p>
+		</object>',
+		esc_attr( $url )
+	);
+}

tests/php/modules/shortcodes/test-class.inline-pdf.php

@@ -0,0 +1,40 @@
+<?php
+/**
+ * Unit test for Inline PDF embeds.
+ *
+ * @package Jetpack
+ * @since   8.4
+ */
+class WP_Test_Jetpack_Shortcodes_Inline_Pdfs extends WP_UnitTestCase {
+
+	/**
+	 * Unit test for Inline PDF embeds.
+	 *
+	 * @author lancewillett
+	 * @covers ::jetpack_inline_pdf_embed_handler
+	 * @since  8.4
+	 */
+	public function test_shortcodes_inline_pdf() {
+		global $post;
+
+		$url  = 'https://jetpackme.files.wordpress.com/2017/08/jetpack-tips-for-hosts.pdf';
+		$post = $this->factory()->post->create_and_get( array( 'post_content' => $url ) );
+
+		setup_postdata( $post );
+
+		// Test HTML version.
+		ob_start();
+		the_content();
+		$actual = ob_get_clean();
+
+		wp_reset_postdata();
+
+		$this->assertContains(
+			sprintf(
+				'<p><object data="%1$s" type="application/pdf" width="100%%" height="800"><p><a href="%1$s">%1$s</a></p></object></p>' . "\n",
+				$url
+			),
+			$actual
+		);
+	}
+}