feat(objectionary#1574): add disabled concurrency test

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

@@ -193,7 +193,14 @@ public void exec() throws IOException {
      */
     @SuppressWarnings({"PMD.AvoidCatchingGenericException", "PMD.ExceptionAsFlowControl"})
     private void parse(final Tojo tojo) throws IOException {
-        final Path source = Paths.get(tojo.get(AssembleMojo.ATTR_EO));
+        String first;
+        try {
+            first = tojo.get(AssembleMojo.ATTR_EO);
+        } catch (final Exception ex) {
+            Logger.error(this, "Failed to parse %s: %[exception]s", tojo, ex);
+            throw ex;
+        }
+        final Path source = Paths.get(first);
         final String name = tojo.get(Tojos.KEY);
         final Footprint footprint;
         if (tojo.exists(AssembleMojo.ATTR_HASH)) {

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

@@ -0,0 +1,62 @@
+package org.eolang.maven;
+
+import com.yegor256.tojos.Tojo;
+import com.yegor256.tojos.Tojos;
+import java.nio.file.Path;
+import java.util.UUID;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+import org.cactoos.Scalar;
+import org.cactoos.experimental.Threads;
+import org.cactoos.number.SumOf;
+import org.hamcrest.MatcherAssert;
+import org.hamcrest.Matchers;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+/**
+ * Concurrency tests for {@link Catalogs}.
+ * All tests in that class must be executed in parallel and in order to be sure that
+ * everything works fine it's important to run the tests many times.
+ * @since 0.29.0
+ * @todo #1574:30min MonoTojo is not thread safe.
+ *  It's not possible to use it in parallel. It should be fixed.
+ *  After that, remove the @Disabled annotation from the test below.
+ */
+class CatalogsConcurrencyTest {
+
+    final static int CORES = Runtime.getRuntime().availableProcessors();
+
+    @Disabled
+    @Test
+    void readsFromTojosConcurrently(@TempDir final Path tmp) {
+        final Tojos tojos = Catalogs.INSTANCE.make(tmp.resolve("foreign"), "json");
+        MatcherAssert.assertThat(
+            new SumOf(
+                new Threads<>(
+                    CORES,
+                    IntStream.range(0, CORES)
+                        .mapToObj(i -> tojos.add(UUID.randomUUID().toString()))
+                        .map(CatalogsConcurrencyTest::task)
+                        .collect(Collectors.toList())
+                )
+            ),
+            Matchers.equalTo(CORES)
+        );
+    }
+
+    private static Scalar<Integer> task(final Tojo tojo) {
+        return () -> {
+            final String uuid = "uuid";
+            tojo.set(uuid, UUID.randomUUID().toString());
+            tojo.get(uuid);
+            tojo.get(uuid);
+            tojo.get(uuid);
+            tojo.get(uuid);
+            return 1;
+        };
+    }
+
+
+}