Add support for outputting to Asciidoc format

README.md

@@ -44,6 +44,7 @@ Available on [Docker Hub](https://hub.docker.com/r/openapitools/openapi-diff/) a
 ```bash
 # docker run openapitools/openapi-diff:latest
 usage: openapi-diff <old> <new>
+    --asciidoc <file>           export diff as asciidoc in given file
     --debug                     Print debugging information
     --error                     Print error information
     --fail-on-changed           Fail if API changed but is backward
@@ -101,6 +102,7 @@ openapi-diff can read OpenAPI specs from JSON files or HTTP URLs.
 ```bash
 $ openapi-diff --help
 usage: openapi-diff <old> <new>
+    --asciidoc <file>           export diff as asciidoc in given file
     --debug                     Print debugging information
     --error                     Print error information
  -h,--help                      print this message
@@ -151,6 +153,8 @@ Add openapi-diff to your POM to show diffs when you test your Maven project. You
         <jsonOutputFileName>${project.basedir}/../maven/target/diff.json</jsonOutputFileName>
         <!-- Supply file path for markdown output to file if desired. -->
         <markdownOutputFileName>${project.basedir}/../maven/target/diff.md</markdownOutputFileName>
+        <!-- Supply file path for Asciidoc output to file if desired. -->
+        <asciidocOutputFileName>${project.basedir}/../maven/target/diff.adoc</asciidocOutputFileName>
       </configuration>
     </execution>
   </executions>

cli/src/main/java/org/openapitools/openapidiff/cli/Main.java

@@ -17,10 +17,7 @@
 import org.apache.commons.lang3.exception.ExceptionUtils;
 import org.openapitools.openapidiff.core.OpenApiCompare;
 import org.openapitools.openapidiff.core.model.ChangedOpenApi;
-import org.openapitools.openapidiff.core.output.ConsoleRender;
-import org.openapitools.openapidiff.core.output.HtmlRender;
-import org.openapitools.openapidiff.core.output.JsonRender;
-import org.openapitools.openapidiff.core.output.MarkdownRender;
+import org.openapitools.openapidiff.core.output.*;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -109,6 +106,13 @@ public static void main(String... args) {
             .argName("file")
             .desc("export diff as json in given file")
             .build());
+    options.addOption(
+        Option.builder()
+            .longOpt("asciidoc")
+            .hasArg()
+            .argName("file")
+            .desc("export diff as asciidoc in given file")
+            .build());
 
     // create the parser
     CommandLineParser parser = new DefaultParser();
@@ -191,6 +195,12 @@ public static void main(String... args) {
         OutputStreamWriter outputStreamWriter = new OutputStreamWriter(outputStream);
         mdRender.render(result, outputStreamWriter);
       }
+      if (line.hasOption("asciidoc")) {
+        AsciidocRender asciidocRender = new AsciidocRender();
+        FileOutputStream outputStream = new FileOutputStream(line.getOptionValue("asciidoc"));
+        OutputStreamWriter outputStreamWriter = new OutputStreamWriter(outputStream);
+        asciidocRender.render(result, outputStreamWriter);
+      }
       if (line.hasOption("text")) {
         FileOutputStream outputStream = new FileOutputStream(line.getOptionValue("text"));
         OutputStreamWriter outputStreamWriter = new OutputStreamWriter(outputStream);

core/src/main/java/org/openapitools/openapidiff/core/output/AsciidocRender.java

@@ -0,0 +1,62 @@
+package org.openapitools.openapidiff.core.output;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class AsciidocRender extends MarkdownRenderBase {
+  private static final Logger LOGGER = LoggerFactory.getLogger(AsciidocRender.class);
+  private static final String H4 = "==== ";
+  private static final String H5 = "===== ";
+  private static final String H6 = "====== ";
+  private static final String CODE = "`";
+  private static final String PRE_LI = "*";
+  private static final String LI = "* ";
+  private static final String HR = "\n'''\n";
+
+  @Override
+  public String getH4() {
+    return H4;
+  }
+
+  @Override
+  public String getH5() {
+    return H5;
+  }
+
+  @Override
+  public String getH6() {
+    return H6;
+  }
+
+  @Override
+  public String getBlockQuote() {
+    throw new UnsupportedOperationException(
+        "Asciidoc does not use blockquote marker;"
+            + "instead it uses blocks like this: \n\n----\nQUOTED TEXT\n----\n");
+  }
+
+  @Override
+  public String getCode() {
+    return CODE;
+  }
+
+  @Override
+  public String getPreListItem() {
+    return PRE_LI;
+  }
+
+  @Override
+  public String getListItem() {
+    return LI;
+  }
+
+  @Override
+  public String getHorizontalRule() {
+    return HR;
+  }
+
+  @Override
+  protected String blockquote(String beginning, String text) {
+    return beginning + "\n----\n" + text.trim() + "\n----\n";
+  }
+}