Asciidoctor does not highlight source code by highlightjs - syntax-highlighting

Question

I try to generate documentation via Spring Rest Docs using Asciidoctor. User manual says: for highlighting source code in documentation I shall to use :source-highlighter: highlightjs attribute in header of .adoc file.
Here's an example of my index.adoc:
:source-highlighter: highlightjs
= Source code listing
Code listings look cool with Asciidoctor and highlight.js with {highlightjs-theme} theme.
[source,groovy]
----
// File: User.groovy
class User {
String username
}
----
[source,sql]
----
CREATE TABLE USER (
ID INT NOT NULL,
USERNAME VARCHAR(40) NOT NULL
);
----
after that I build and run application, and here's an generated doc without highlighting of source code:
My maven plugin configuration:
<plugin>
<groupId>org.asciidoctor</groupId>
<artifactId>asciidoctor-maven-plugin</artifactId>
<version>1.5.3</version>
<executions>
<execution>
<id>generate-docs</id>
<phase>prepare-package</phase>
<goals>
<goal>process-asciidoc</goal>
</goals>
<configuration>
<backend>html</backend>
<doctype>book</doctype>
</configuration>
</execution>
</executions>
<dependencies>
<dependency>
<groupId>org.springframework.restdocs</groupId>
<artifactId>spring-restdocs-asciidoctor</artifactId>
<version>2.0.2.RELEASE</version>
</dependency>
</dependencies>
</plugin>
What am I doing wrong?
P.S. Also I have tried to install highlight.js locally with renaming highlight/highlight.pack.js to highlight/highlight.min.js and highlight/styles/github.css to highlight/styles/github.min.css and so on, as user manual says but there is no result too

Answer 1

Unfortunately, as you probably figured out, Groovy is not included in the standard highlight.js language pack. It only includes the ones in the "common" section. SQL would work though. As you can see in this picture, the SQL part works with my setup out of the box, but not Groovy.
To fix the Groovy code, you can either use Java as the language (fine for a lot of Groovy code examples) or download the custom HighlightJS pack with Groovy checked. I'm guessing that's where you got to.
If you are using the custom HighlightJS pack, I ran into a similar issue at first. When I went into developer tools in the browser, it showed that the highlight.js files were not found. Another hint that was the problem is that all the Spring REST Docs examples lost their highlighting too. Although the Asciidoctor manual says to put it into the same folder and it should copy over automatically, with Gradle, I still had to tell it to include the highlight files using the resources config option. I'm not a Maven user, but maybe the Maven plugin has a similar setup?
After I fixed the config, it worked for both Groovy and SQL
so I hope that will work for you too.