UrlBuilder has absolute(to) method.

lib/src/main/groovy/com/jessebrault/ssg/url/PathBasedUrlBuilder.groovy

@@ -5,10 +5,12 @@ import java.nio.file.Path
 class PathBasedUrlBuilder implements UrlBuilder {
 
     private final String absolute
+    private final String baseUrl
     private final Path fromDirectory
 
     PathBasedUrlBuilder(String targetPath, String baseUrl) {
         this.absolute = baseUrl + '/' + targetPath
+        this.baseUrl = baseUrl
         def fromFilePath = Path.of(targetPath)
         if (fromFilePath.parent) {
             this.fromDirectory = fromFilePath.parent
@@ -22,6 +24,11 @@ class PathBasedUrlBuilder implements UrlBuilder {
         this.absolute
     }
 
+    @Override
+    String absolute(String to) {
+        this.baseUrl + '/' + to
+    }
+
     @Override
     String relative(String to) {
         this.fromDirectory.relativize(Path.of(to)).toString()

lib/src/main/groovy/com/jessebrault/ssg/url/UrlBuilder.groovy

@@ -2,5 +2,6 @@ package com.jessebrault.ssg.url
 
 interface UrlBuilder {
     String getAbsolute()
+    String absolute(String to)
     String relative(String to)
 }

lib/src/testFixtures/groovy/com/jessebrault/ssg/url/AbstractUrlBuilderTests.groovy

@@ -38,4 +38,12 @@ abstract class AbstractUrlBuilderTests {
         )
     }
 
+    @Test
+    void absoluteToCorrect() {
+        assertEquals(
+                'https://test.com/images/test.jpg',
+                this.getUrlBuilder('', 'https://test.com').absolute('images/test.jpg')
+        )
+    }
+
 }