File Block: Add a deprecation for the button element class name (#45159)

* File Block: Add a deprecation for the button element class name

* switch v2 and v3

* Add fixtures for new deprecation

* Fix deprecation comment

* Remove new fixture for now as failing a php test for some reason

Co-authored-by: Glen Davies <glen.davies@automattic.com>

packages/block-library/src/file/deprecated.js

@@ -14,7 +14,7 @@ import {
 import { __, sprintf } from '@wordpress/i18n';
 
 // Version of the file block without PR#43050 removing the translated aria-label.
-const v2 = {
+const v3 = {
 	attributes: {
 		id: {
 			type: 'number',
@@ -143,6 +143,134 @@ const v2 = {
 	},
 };
 
+// In #41239 the button was made an element button which added a `wp-element-button` classname
+// to the download link element.
+const v2 = {
+	attributes: {
+		id: {
+			type: 'number',
+		},
+		href: {
+			type: 'string',
+		},
+		fileId: {
+			type: 'string',
+			source: 'attribute',
+			selector: 'a:not([download])',
+			attribute: 'id',
+		},
+		fileName: {
+			type: 'string',
+			source: 'html',
+			selector: 'a:not([download])',
+		},
+		textLinkHref: {
+			type: 'string',
+			source: 'attribute',
+			selector: 'a:not([download])',
+			attribute: 'href',
+		},
+		textLinkTarget: {
+			type: 'string',
+			source: 'attribute',
+			selector: 'a:not([download])',
+			attribute: 'target',
+		},
+		showDownloadButton: {
+			type: 'boolean',
+			default: true,
+		},
+		downloadButtonText: {
+			type: 'string',
+			source: 'html',
+			selector: 'a[download]',
+		},
+		displayPreview: {
+			type: 'boolean',
+		},
+		previewHeight: {
+			type: 'number',
+			default: 600,
+		},
+	},
+	supports: {
+		anchor: true,
+		align: true,
+	},
+	save( { attributes } ) {
+		const {
+			href,
+			fileId,
+			fileName,
+			textLinkHref,
+			textLinkTarget,
+			showDownloadButton,
+			downloadButtonText,
+			displayPreview,
+			previewHeight,
+		} = attributes;
+
+		const pdfEmbedLabel = RichText.isEmpty( fileName )
+			? __( 'PDF embed' )
+			: sprintf(
+					/* translators: %s: filename. */
+					__( 'Embed of %s.' ),
+					fileName
+			  );
+
+		const hasFilename = ! RichText.isEmpty( fileName );
+
+		// Only output an `aria-describedby` when the element it's referring to is
+		// actually rendered.
+		const describedById = hasFilename ? fileId : undefined;
+
+		return (
+			href && (
+				<div { ...useBlockProps.save() }>
+					{ displayPreview && (
+						<>
+							<object
+								className="wp-block-file__embed"
+								data={ href }
+								type="application/pdf"
+								style={ {
+									width: '100%',
+									height: `${ previewHeight }px`,
+								} }
+								aria-label={ pdfEmbedLabel }
+							/>
+						</>
+					) }
+					{ hasFilename && (
+						<a
+							id={ describedById }
+							href={ textLinkHref }
+							target={ textLinkTarget }
+							rel={
+								textLinkTarget
+									? 'noreferrer noopener'
+									: undefined
+							}
+						>
+							<RichText.Content value={ fileName } />
+						</a>
+					) }
+					{ showDownloadButton && (
+						<a
+							href={ href }
+							className="wp-block-file__button"
+							download={ true }
+							aria-describedby={ describedById }
+						>
+							<RichText.Content value={ downloadButtonText } />
+						</a>
+					) }
+				</div>
+			)
+		);
+	},
+};
+
 // Version of the file block without PR#28062 accessibility fix.
 const v1 = {
 	attributes: {
@@ -255,6 +383,6 @@ const v1 = {
 	},
 };
 
-const deprecated = [ v2, v1 ];
+const deprecated = [ v3, v2, v1 ];
 
 export default deprecated;