feat(#123): Program also use Source for linting

pom.xml

@@ -359,7 +359,7 @@
                     <class>org.eolang.lints.PkMonoTest</class>
                     <class>org.eolang.lints.LtByXslTest</class>
                     <class>org.eolang.lints.PkWpaTest</class>
-                    <class>org.eolang.lints.ProgramTest</class>
+                    <class>org.eolang.lints.EoPackageTest</class>
                     <class>org.eolang.lints.LtUnlintNonExistingDefectWpaTest</class>
                     <class>org.eolang.lints.LtTestNotVerbTest</class>
                     <class>org.eolang.lints.WpaLintsTest</class>

src/it/lints-it/src/test/java/org/eolang/lints/it/LintsItTest.java

@@ -6,7 +6,8 @@
 
 import com.jcabi.xml.XMLDocument;
 import java.io.IOException;
-import org.eolang.lints.Source;
+import java.util.Map;
+import org.eolang.lints.Program;
 import org.hamcrest.MatcherAssert;
 import org.hamcrest.Matchers;
 import org.junit.jupiter.api.Test;
@@ -22,7 +23,12 @@ final class LintsItTest {
     void lintsSource() throws IOException {
         MatcherAssert.assertThat(
             "passes with no exceptions",
-            new Source(new XMLDocument("<object/>")).defects(),
+            new Program(
+                Map.of(
+                    "main.eo",
+                    new XMLDocument("<object/>")
+                )
+            ).defects(),
             Matchers.notNullValue()
         );
     }

src/main/java/org/eolang/lints/EoPackage.java

@@ -0,0 +1,163 @@
+/*
+ * SPDX-FileCopyrightText: Copyright (c) 2016-2025 Objectionary.com
+ * SPDX-License-Identifier: MIT
+ */
+package org.eolang.lints;
+
+import com.jcabi.xml.XML;
+import com.jcabi.xml.XMLDocument;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+import org.cactoos.iterable.Sticky;
+import org.cactoos.list.ListOf;
+import org.cactoos.list.Synced;
+
+/**
+ * Whole EO package, as collection of XMIR sources to analyze.
+ * @since 0.1.0
+ */
+final class EoPackage {
+
+    /**
+     * Collection of wpa lints, preloaded on JVM start.
+     */
+    private static final Iterable<Lint<Map<String, XML>>> WPA = new Synced<>(
+        new ListOf<>(
+            new Sticky<>(
+                new PkWpa()
+            )
+        )
+    );
+
+    /**
+     * Lints to use.
+     */
+    private final Iterable<Lint<Map<String, XML>>> lints;
+
+    /**
+     * The package of XMIR files.
+     */
+    private final Map<String, XML> pkg;
+
+    /**
+     * Ctor.
+     * @param dirs The directory
+     * @throws IOException If fails
+     */
+    EoPackage(final Path... dirs) throws IOException {
+        this(Arrays.asList(dirs));
+    }
+
+    /**
+     * Ctor.
+     *
+     * <p>Pay attention, it's important to use {@link Collection} as a type
+     * of argument, because {@link Path} implements {@link Iterable}.</p>
+     *
+     * @param dirs The directory
+     * @throws IOException If fails
+     */
+    EoPackage(final Collection<Path> dirs) throws IOException {
+        this(EoPackage.discover(dirs));
+    }
+
+    /**
+     * Ctor.
+     * @param map The map with them
+     */
+    EoPackage(final Map<String, XML> map) {
+        this(map, EoPackage.WPA);
+    }
+
+    /**
+     * Ctor.
+     * @param map The map with them
+     * @param list The lints
+     */
+    EoPackage(final Map<String, XML> map, final Iterable<Lint<Map<String, XML>>> list) {
+        this.pkg = Collections.unmodifiableMap(map);
+        this.lints = list;
+    }
+
+    /**
+     * Package with disabled lints.
+     * @param names Lint names
+     * @return Package analysis without specifics names
+     */
+    public EoPackage without(final String... names) {
+        return new EoPackage(this.pkg, new WpaWithout(names));
+    }
+
+    /**
+     * Find all possible defects in the EO package.
+     * @return All defects found
+     */
+    public Collection<Defect> defects() {
+        final Collection<Defect> messages = new ArrayList<>(0);
+        for (final Lint<Map<String, XML>> lint : this.lints) {
+            try {
+                messages.addAll(new ScopedDefects(lint.defects(this.pkg), "WPA"));
+            } catch (final IOException exception) {
+                throw new IllegalStateException(
+                    String.format(
+                        "Failed to find defects in the '%s' package with '%s' lint",
+                        this.pkg,
+                        lint
+                    ),
+                    exception
+                );
+            }
+        }
+        return messages;
+    }
+
+    /**
+     * Discover all XMIR files in the directory.
+     * @param dirs The directories to search for XMIR files in (recursively)
+     * @return Map of XMIR files
+     * @throws IOException If fails
+     */
+    private static Map<String, XML> discover(final Iterable<Path> dirs) throws IOException {
+        final Map<String, XML> map = new HashMap<>(0);
+        for (final Path dir : dirs) {
+            map.putAll(EoPackage.discover(dir));
+        }
+        return map;
+    }
+
+    /**
+     * Discover all XMIR files in the directory.
+     * @param dir The directories to search for XMIR files in (recursively)
+     * @return Map of XMIR files
+     * @throws IOException If fails
+     */
+    private static Map<String, XML> discover(final Path dir) throws IOException {
+        try (Stream<Path> walk = Files.walk(dir)) {
+            return walk
+                .filter(Files::isRegularFile)
+                .collect(
+                    Collectors.toMap(
+                        path -> new XmirKey(path, dir).asString(),
+                        path -> {
+                            try {
+                                return new XMLDocument(path);
+                            } catch (final FileNotFoundException ex) {
+                                throw new IllegalArgumentException(ex);
+                            }
+                        }
+                    )
+                );
+        }
+    }
+
+}

src/main/java/org/eolang/lints/PkWpa.java

@@ -13,8 +13,8 @@
 import org.cactoos.list.ListOf;
 
 /**
- * A collection of lints for Whole Program Analysis (WPA),
- * provided by the {@link Program} class.
+ * A collection of lints for Whole Package Analysis (WPA),
+ * provided by the {@link EoPackage} class.
  *
  * <p>This class is thread-safe.</p>
  *