bug(#3811): relative /program/@source path

eo-maven-plugin/pom.xml

@@ -194,6 +194,10 @@ SOFTWARE.
     <dependency>
       <groupId>com.yegor256</groupId>
       <artifactId>mktmp</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>com.github.volodya-lombrozo</groupId>
+      <artifactId>xnav</artifactId>
       <!-- version from parent POM -->
     </dependency>
     <dependency>

eo-maven-plugin/src/main/java/org/eolang/maven/CopyMojo.java

@@ -67,18 +67,6 @@ public final class CopyMojo extends SafeMojo {
         Pattern.MULTILINE
     );
 
-    /**
-     * Directory in which .eo files are located.
-     *
-     * @checkstyle MemberNameCheck (7 lines)
-     */
-    @Parameter(
-        property = "eo.sourcesDir",
-        required = true,
-        defaultValue = "${project.basedir}/src/main/eo"
-    )
-    private File sourcesDir;
-
     /**
      * Target directory with resources to be packaged in JAR.
      *

eo-maven-plugin/src/main/java/org/eolang/maven/ParseMojo.java

@@ -131,7 +131,7 @@ private int parsed(final ForeignTojo tojo) throws Exception {
         final Path target = new Place(name).make(base, AssembleMojo.XMIR);
         tojo.withXmir(
             new FpDefault(
-                ParseMojo.parse(name),
+                this.parse(name),
                 this.cache.toPath().resolve(ParseMojo.CACHE),
                 this.plugin.getVersion(),
                 new TojoHash(tojo),
@@ -158,12 +158,12 @@ private int parsed(final ForeignTojo tojo) throws Exception {
      * @param name Name of the EO object
      * @return Function that parses EO source
      */
-    private static Func<Path, String> parse(final String name) {
+    private Func<Path, String> parse(final String name) {
         return source -> {
             final String parsed = new XMLDocument(
                 new Xembler(
                     new Directives().xpath("/program").attr(
-                        "source", source.toAbsolutePath()
+                        "source",  this.sourcesDir.toPath().relativize(source.toAbsolutePath())
                     )
                 ).applyQuietly(new EoSyntax(name, new InputOf(source)).parsed().inner())
             ).toString();

eo-maven-plugin/src/main/java/org/eolang/maven/SafeMojo.java

@@ -113,6 +113,19 @@ abstract class SafeMojo extends AbstractMojo {
     @Parameter(property = "eo.foreignFormat", required = true, defaultValue = "csv")
     protected String foreignFormat = "csv";
 
+    /**
+     * Directory in which .eo files are located.
+     *
+     * @checkstyle VisibilityModifierCheck (10 lines)
+     * @checkstyle MemberNameCheck (8 lines)
+     */
+    @Parameter(
+        property = "eo.sourcesDir",
+        required = true,
+        defaultValue = "${project.basedir}/src/main/eo"
+    )
+    protected File sourcesDir;
+
     /**
      * Target directory.
      * @checkstyle MemberNameCheck (10 lines)

eo-maven-plugin/src/test/java/org/eolang/maven/ParseMojoTest.java

@@ -23,6 +23,7 @@
  */
 package org.eolang.maven;
 
+import com.github.lombrozo.xnav.Xnav;
 import com.yegor256.Mktmp;
 import com.yegor256.MktmpResolver;
 import com.yegor256.WeAreOnline;
@@ -224,6 +225,31 @@ void parsesConcurrentlyWithLotsOfPrograms(@Mktmp final Path temp) throws IOExcep
         }
     }
 
+    @Test
+    void injectsRelativeSource(@Mktmp final Path temp) throws IOException {
+        final String path = new Xnav(
+            new FakeMaven(temp)
+                .withHelloWorld()
+                .execute(ParseMojo.class)
+                .result()
+                .get(String.format("target/%s/foo/x/main.%s", ParseMojo.DIR, AssembleMojo.XMIR))
+        )
+            .element("program")
+            .attribute("source")
+            .text()
+            .get();
+        MatcherAssert.assertThat(
+            "The /program/@source attribute must be a relative path",
+            Paths.get(path).isAbsolute(),
+            Matchers.is(false)
+        );
+        MatcherAssert.assertThat(
+            "The /program/@source attribute must be a relative path to EO source",
+            path,
+            Matchers.equalTo(Paths.get("foo/x/main.eo").toString())
+        );
+    }
+
     /**
      * The mojo that does nothing, but executes infinitely.
      * @since 0.29