Fix block validation error message (#13499)

* Rename variable to make code more clear

* Fix display of expected and actual block HTML

The variable were in the wrong order, making the message confusing. It
would show the actual HTML as the expected HTML and visa versa.

* Change wording to be more clear

Expected & Actual were confusing words to use in this content. This
change makes the message actually reflect what the values are.

* Regenerate docs

packages/blocks/README.md

@@ -574,7 +574,7 @@ Logs to console in development environments when invalid.
 
 -   **blockTypeOrName** `(string|Object)`: Block type.
 -   **attributes** `Object`: Parsed block attributes.
--   **innerHTML** `string`: Original block content.
+-   **originalBlockContent** `string`: Original block content.
 
 **Returns**
 

packages/blocks/src/api/validation.js

@@ -620,30 +620,30 @@ export function isEquivalentHTML( actual, expected ) {
  *
  * Logs to console in development environments when invalid.
  *
- * @param {string|Object} blockTypeOrName Block type.
- * @param {Object}        attributes      Parsed block attributes.
- * @param {string}        innerHTML       Original block content.
+ * @param {string|Object} blockTypeOrName      Block type.
+ * @param {Object}        attributes           Parsed block attributes.
+ * @param {string}        originalBlockContent Original block content.
  *
  * @return {boolean} Whether block is valid.
  */
-export function isValidBlockContent( blockTypeOrName, attributes, innerHTML ) {
+export function isValidBlockContent( blockTypeOrName, attributes, originalBlockContent ) {
 	const blockType = normalizeBlockType( blockTypeOrName );
-	let saveContent;
+	let generatedBlockContent;
 	try {
-		saveContent = getSaveContent( blockType, attributes );
+		generatedBlockContent = getSaveContent( blockType, attributes );
 	} catch ( error ) {
 		log.error( 'Block validation failed because an error occurred while generating block content:\n\n%s', error.toString() );
 		return false;
 	}
 
-	const isValid = isEquivalentHTML( innerHTML, saveContent );
+	const isValid = isEquivalentHTML( originalBlockContent, generatedBlockContent );
 	if ( ! isValid ) {
 		log.error(
-			'Block validation failed for `%s` (%o).\n\nExpected:\n\n%s\n\nActual:\n\n%s',
+			'Block validation failed for `%s` (%o).\n\nContent generated by `save` function:\n\n%s\n\nContent retrieved from post body:\n\n%s',
 			blockType.name,
 			blockType,
-			saveContent,
-			innerHTML
+			generatedBlockContent,
+			originalBlockContent
 		);
 	}