feat(context): naive storage for values in a context

Refs: #4

Author: nergal-perm

.editorconfig

@@ -68,7 +68,7 @@ ij_java_case_statement_on_separate_line = true
 ij_java_catch_on_new_line = false
 ij_java_class_annotation_wrap = split_into_lines
 ij_java_class_brace_style = end_of_line
-ij_java_class_count_to_use_import_on_demand = 5
+ij_java_class_count_to_use_import_on_demand = 100
 ij_java_class_names_in_javadoc = 1
 ij_java_do_not_indent_top_level_class_members = false
 ij_java_do_not_wrap_after_single_annotation = false
@@ -104,7 +104,7 @@ ij_java_for_statement_wrap = off
 ij_java_generate_final_locals = false
 ij_java_generate_final_parameters = false
 ij_java_if_brace_force = never
-ij_java_imports_layout = *,|,javax.**,java.**,|,$*
+ij_java_imports_layout = *
 ij_java_indent_case_from_switch = true
 ij_java_insert_inner_class_imports = false
 ij_java_insert_override_annotation = true
@@ -124,7 +124,7 @@ ij_java_keep_simple_methods_in_one_line = false
 ij_java_label_indent_absolute = false
 ij_java_label_indent_size = 0
 ij_java_lambda_brace_style = end_of_line
-ij_java_layout_static_imports_separately = true
+ij_java_layout_static_imports_separately = false
 ij_java_line_comment_add_space = false
 ij_java_line_comment_at_first_column = true
 ij_java_method_annotation_wrap = split_into_lines
@@ -134,7 +134,7 @@ ij_java_method_parameters_new_line_after_left_paren = false
 ij_java_method_parameters_right_paren_on_new_line = false
 ij_java_method_parameters_wrap = off
 ij_java_modifier_list_wrap = false
-ij_java_names_count_to_use_import_on_demand = 3
+ij_java_names_count_to_use_import_on_demand = 100
 ij_java_packages_to_use_import_on_demand = java.awt.*,javax.swing.*
 ij_java_parameter_annotation_wrap = off
 ij_java_parentheses_expression_new_line_after_left_paren = false

src/main/java/ewc/composer/core/ChainContext.java

@@ -0,0 +1,83 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2024 Decision-Driven Development
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package ewc.composer.core;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Supplier;
+
+/**
+ * I am a context for a chain of operations. I provide a way to pass data between operations.
+ * I can (and should, actually) be extended in order to provide application-specific amenities to
+ * all the operations in the chain.
+ *
+ * @since 0.1.0
+ */
+public class ChainContext {
+    /**
+     * The storage for all the data that needs to be passed between operations. The data is stored
+     * as a map of keys and suppliers of lists of strings. The suppliers are used to provide the
+     * data only when it is needed, so the real data is not stored in the map until it is requested.
+     */
+    private final Map<String, Supplier<List<String>>> data;
+
+    /**
+     * Ctor.
+     */
+    public ChainContext() {
+        this(new HashMap<>());
+    }
+
+    /**
+     * Ctor.
+     *
+     * @param data The data to store in the context.
+     */
+    private ChainContext(final Map<String, Supplier<List<String>>> data) {
+        this.data = data;
+    }
+
+    /**
+     * Retrieves the data from the context by the key. If the data is not present, an empty list is
+     * returned.
+     *
+     * @param key The key to retrieve the data by.
+     * @return The data stored under the key or an empty list if the data is not present.
+     */
+    public List<String> fetch(final String key) {
+        return this.data.getOrDefault(key, List::of).get();
+    }
+
+    /**
+     * Adds the data to the context under the provided key.
+     *
+     * @param key The key to store the data under.
+     * @param supplier The supplier of the data to store.
+     */
+    public void add(final String key, final Supplier<List<String>> supplier) {
+        this.data.put(key, supplier);
+    }
+}

src/test/java/ewc/composer/core/ChainContextTest.java

@@ -0,0 +1,59 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2024 Decision-Driven Development
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package ewc.composer.core;
+
+import java.util.List;
+import org.hamcrest.MatcherAssert;
+import org.hamcrest.Matchers;
+import org.junit.jupiter.api.Test;
+
+/**
+ * I am a test for the {@link ChainContext}.
+ *
+ * @since 0.1.0
+ */
+final class ChainContextTest {
+    @Test
+    void shouldGetValueOutOfContext() {
+        final ChainContext target = new ChainContext();
+        final List<String> actual = target.fetch("data-by-key");
+        MatcherAssert.assertThat(
+            "Should be empty for a non-existent key?",
+            actual,
+            Matchers.empty()
+        );
+    }
+
+    @Test
+    void shouldBeAbleToAddNewData() {
+        final ChainContext target = new ChainContext();
+        target.add("data-by-key", () -> List.of("value"));
+        MatcherAssert.assertThat(
+            "Should be able to add and retrieve data",
+            target.fetch("data-by-key"),
+            Matchers.contains("value")
+        );
+    }
+}