feat: add ContainerBlock layout block support

slack-api-model-kotlin-extension/src/main/kotlin/com/slack/api/model/kotlin_extension/block/ContainerBlockBuilder.kt

@@ -0,0 +1,86 @@
+package com.slack.api.model.kotlin_extension.block
+
+import com.slack.api.model.block.ContainerBlock
+import com.slack.api.model.block.LayoutBlock
+import com.slack.api.model.block.RichTextBlock
+import com.slack.api.model.block.composition.PlainTextObject
+import com.slack.api.model.block.composition.TextObject
+import com.slack.api.model.block.element.ImageElement
+import com.slack.api.model.kotlin_extension.block.container.MultiLayoutBlockContainer
+
+@BlockLayoutBuilder
+class ContainerBlockBuilder : Builder<ContainerBlock> {
+    private var blockId: String? = null
+    private var title: TextObject? = null
+    private var richTextTitle: RichTextBlock? = null
+    private var subtitle: TextObject? = null
+    private var childBlocks: List<LayoutBlock>? = null
+    private var width: String? = null
+    private var icon: ImageElement? = null
+    private var isCollapsible: Boolean? = null
+    private var defaultCollapsed: Boolean? = null
+    private var hasHeaderDivider: Boolean? = null
+
+    fun blockId(id: String) {
+        blockId = id
+    }
+
+    fun title(text: String, emoji: Boolean? = null) {
+        title = PlainTextObject(text, emoji)
+    }
+
+    fun title(textObject: TextObject) {
+        title = textObject
+    }
+
+    fun richTextTitle(richText: RichTextBlock) {
+        richTextTitle = richText
+    }
+
+    fun subtitle(text: String, emoji: Boolean? = null) {
+        subtitle = PlainTextObject(text, emoji)
+    }
+
+    fun subtitle(textObject: TextObject) {
+        subtitle = textObject
+    }
+
+    fun childBlocks(builder: MultiLayoutBlockContainer.() -> Unit) {
+        childBlocks = MultiLayoutBlockContainer().apply(builder).underlying
+    }
+
+    fun width(width: String) {
+        this.width = width
+    }
+
+    fun icon(imageUrl: String, altText: String) {
+        icon = ImageElement.builder().imageUrl(imageUrl).altText(altText).build()
+    }
+
+    fun isCollapsible(collapsible: Boolean) {
+        isCollapsible = collapsible
+    }
+
+    fun defaultCollapsed(collapsed: Boolean) {
+        defaultCollapsed = collapsed
+    }
+
+    fun hasHeaderDivider(divider: Boolean) {
+        hasHeaderDivider = divider
+    }
+
+    override fun build(): ContainerBlock {
+        return ContainerBlock.builder()
+            .blockId(blockId)
+            .title(title)
+            .richTextTitle(richTextTitle)
+            .subtitle(subtitle)
+            .childBlocks(childBlocks ?: ArrayList())
+            .width(width)
+            .icon(icon)
+            .isCollapsible(isCollapsible)
+            .defaultCollapsed(defaultCollapsed)
+            .hasHeaderDivider(hasHeaderDivider)
+            .build()
+    }
+}

slack-api-model-kotlin-extension/src/main/kotlin/com/slack/api/model/kotlin_extension/block/container/MultiLayoutBlockContainer.kt

@@ -67,4 +67,8 @@ class MultiLayoutBlockContainer : LayoutBlockDsl {
     override fun shareShortcut(builder: ShareShortcutBlockBuilder.() -> Unit) {
         underlying += ShareShortcutBlockBuilder().apply(builder).build()
     }
+
+    override fun container(builder: ContainerBlockBuilder.() -> Unit) {
+        underlying += ContainerBlockBuilder().apply(builder).build()
+    }
 }

slack-api-model-kotlin-extension/src/main/kotlin/com/slack/api/model/kotlin_extension/block/dsl/LayoutBlockDsl.kt

@@ -95,4 +95,11 @@ interface LayoutBlockDsl {
      * @see <a href="https://tools.slack.dev/deno-slack-sdk/">Next generation platform</a>
      */
     fun shareShortcut(builder: ShareShortcutBlockBuilder.() -> Unit)
+
+    /**
+     * A container block groups related blocks together into a visually distinct section.
+     *
+     * @see <a href="https://docs.slack.dev/reference/block-kit/blocks/container-block">Container documentation</a>
+     */
+    fun container(builder: ContainerBlockBuilder.() -> Unit)
 }

slack-api-model/src/main/java/com/slack/api/model/block/Blocks.java

@@ -147,10 +147,14 @@
         return configurator.configure(CarouselBlock.builder()).build();
     }
 
+    // ContainerBlock
+
+    public static ContainerBlock container(ModelConfigurator<ContainerBlock.ContainerBlockBuilder> configurator) {
+        return configurator.configure(ContainerBlock.builder()).build();
     // TaskCardBlock
 
     public static TaskCardBlock taskCard(ModelConfigurator<TaskCardBlock.TaskCardBlockBuilder> configurator) {
         return configurator.configure(TaskCardBlock.builder()).build();
     }
 
 }

slack-api-model/src/main/java/com/slack/api/model/block/ContainerBlock.java

@@ -0,0 +1,44 @@
+package com.slack.api.model.block;
+
+import com.slack.api.model.block.composition.TextObject;
+import com.slack.api.model.block.element.ImageElement;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * https://docs.slack.dev/reference/block-kit/blocks/container-block
+ */
+@Data
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public class ContainerBlock implements LayoutBlock {
+    public static final String TYPE = "container";
+    private final String type = TYPE;
+
+    private TextObject title;
+
+    private RichTextBlock richTextTitle;
+
+    private TextObject subtitle;
+
+    @Builder.Default
+    private List<LayoutBlock> childBlocks = new ArrayList<>();
+
+    private String width;
+
+    private ImageElement icon;
+
+    private Boolean isCollapsible;
+
+    private Boolean defaultCollapsed;
+
+    private Boolean hasHeaderDivider;
+
+    private String blockId;
+}

slack-api-model/src/test/java/test_locally/api/model/block/BlockKitTest.java

@@ -2169,6 +2169,154 @@ public void parseCarouselBlock() {
         assertThat(reparsed.getElements().get(0).getType(), is("card"));
     }
 
+    @Test
+    public void parseContainerBlock() {
+        // https://docs.slack.dev/reference/block-kit/blocks/container-block
+        String json = "{\"blocks\":[\n" +
+                "  {\n" +
+                "    \"type\": \"container\",\n" +
+                "    \"block_id\": \"container1\",\n" +
+                "    \"title\": {\n" +
+                "      \"type\": \"plain_text\",\n" +
+                "      \"text\": \"Container Title\"\n" +
+                "    },\n" +
+                "    \"subtitle\": {\n" +
+                "      \"type\": \"mrkdwn\",\n" +
+                "      \"text\": \"*Bold* subtitle\"\n" +
+                "    },\n" +
+                "    \"width\": \"wide\",\n" +
+                "    \"is_collapsible\": true,\n" +
+                "    \"default_collapsed\": false,\n" +
+                "    \"icon\": {\n" +
+                "      \"type\": \"image\",\n" +
+                "      \"image_url\": \"https://example.com/icon.png\",\n" +
+                "      \"alt_text\": \"icon\"\n" +
+                "    },\n" +
+                "    \"child_blocks\": [\n" +
+                "      {\n" +
+                "        \"type\": \"section\",\n" +
+                "        \"text\": {\n" +
+                "          \"type\": \"mrkdwn\",\n" +
+                "          \"text\": \"Section inside container.\"\n" +
+                "        }\n" +
+                "      },\n" +
+                "      {\n" +
+                "        \"type\": \"divider\"\n" +
+                "      }\n" +
+                "    ]\n" +
+                "  }\n" +
+                "]}";
+        Gson gson = GsonFactory.createSnakeCase();
+        Message message = gson.fromJson(json, Message.class);
+        assertThat(message, is(notNullValue()));
+        assertThat(message.getBlocks().size(), is(1));
+
+        ContainerBlock container = (ContainerBlock) message.getBlocks().get(0);
+        assertThat(container.getType(), is("container"));
+        assertThat(container.getBlockId(), is("container1"));
+        assertThat(container.getTitle().getType(), is("plain_text"));
+        assertThat(container.getTitle().getText(), is("Container Title"));
+        assertThat(container.getSubtitle().getType(), is("mrkdwn"));
+        assertThat(container.getWidth(), is("wide"));
+        assertThat(container.getIsCollapsible(), is(true));
+        assertThat(container.getDefaultCollapsed(), is(false));
+        assertThat(container.getIcon().getImageUrl(), is("https://example.com/icon.png"));
+        assertThat(container.getChildBlocks().size(), is(2));
+        assertThat(container.getChildBlocks().get(0), is(instanceOf(SectionBlock.class)));
+        assertThat(container.getChildBlocks().get(1), is(instanceOf(DividerBlock.class)));
+
+        // Round-trip
+        Message roundTrip = gson.fromJson(gson.toJson(message), Message.class);
+        ContainerBlock reparsed = (ContainerBlock) roundTrip.getBlocks().get(0);
+        assertThat(reparsed.getBlockId(), is("container1"));
+        assertThat(reparsed.getChildBlocks().size(), is(2));
+    }
+
+    @Test
+    public void parseContainerBlockWithRichTextTitle() {
+        String json = "{\"blocks\":[\n" +
+                "  {\n" +
+                "    \"type\": \"container\",\n" +
+                "    \"rich_text_title\": {\n" +
+                "      \"type\": \"rich_text\",\n" +
+                "      \"elements\": [\n" +
+                "        {\n" +
+                "          \"type\": \"rich_text_section\",\n" +
+                "          \"elements\": [\n" +
+                "            {\n" +
+                "              \"type\": \"text\",\n" +
+                "              \"text\": \"Rich Title\"\n" +
+                "            }\n" +
+                "          ]\n" +
+                "        }\n" +
+                "      ]\n" +
+                "    },\n" +
+                "    \"child_blocks\": [\n" +
+                "      {\n" +
+                "        \"type\": \"divider\"\n" +
+                "      }\n" +
+                "    ]\n" +
+                "  }\n" +
+                "]}";
+        Gson gson = GsonFactory.createSnakeCase();
+        Message message = gson.fromJson(json, Message.class);
+        assertThat(message, is(notNullValue()));
+        ContainerBlock container = (ContainerBlock) message.getBlocks().get(0);
+        assertThat(container.getRichTextTitle(), is(notNullValue()));
+        assertThat(container.getRichTextTitle().getType(), is("rich_text"));
+        assertThat(container.getRichTextTitle().getElements().size(), is(1));
+        assertThat(container.getTitle(), is(nullValue()));
+    }
+
+    @Test
+    public void parseContainerBlockWithHeaderDivider() {
+        String json = "{\"blocks\":[\n" +
+                "  {\n" +
+                "    \"type\": \"container\",\n" +
+                "    \"title\": {\n" +
+                "      \"type\": \"plain_text\",\n" +
+                "      \"text\": \"With divider\"\n" +
+                "    },\n" +
+                "    \"has_header_divider\": true,\n" +
+                "    \"child_blocks\": [\n" +
+                "      {\n" +
+                "        \"type\": \"divider\"\n" +
+                "      }\n" +
+                "    ]\n" +
+                "  }\n" +
+                "]}";
+        Gson gson = GsonFactory.createSnakeCase();
+        Message message = gson.fromJson(json, Message.class);
+        ContainerBlock container = (ContainerBlock) message.getBlocks().get(0);
+        assertThat(container.getHasHeaderDivider(), is(true));
+        assertThat(container.getIsCollapsible(), is(nullValue()));
+    }
+
+    @Test
+    public void buildContainerBlock() {
+        ContainerBlock container = container(c -> c
+                .blockId("container1")
+                .title(com.slack.api.model.block.composition.PlainTextObject.builder().text("Title").build())
+                .width("wide")
+                .isCollapsible(true)
+                .childBlocks(Arrays.asList(
+                        divider()
+                ))
+        );
+        assertThat(container.getType(), is("container"));
+        assertThat(container.getBlockId(), is("container1"));
+
+        Gson gson = GsonFactory.createSnakeCase();
+        Message message = new Message();
+        message.setBlocks(asBlocks(container));
+        Message reparsed = gson.fromJson(gson.toJson(message), Message.class);
+        ContainerBlock parsedContainer = (ContainerBlock) reparsed.getBlocks().get(0);
+        assertThat(parsedContainer.getBlockId(), is("container1"));
+        assertThat(parsedContainer.getWidth(), is("wide"));
+        assertThat(parsedContainer.getIsCollapsible(), is(true));
+        assertThat(parsedContainer.getChildBlocks().size(), is(1));
+    }
+
     @Test
     public void buildCarouselBlock() {
         CarouselBlock carousel = carousel(c -> c

slack-api-model/src/test/java/test_locally/api/model/block/BlocksTest.java

@@ -117,6 +117,14 @@ public void testCarousel() {
         ))), is(notNullValue()));
     }
 
+    @Test
+    public void testContainer() {
+        assertThat(container(c -> c.blockId("container-1")
+                .title(com.slack.api.model.block.composition.PlainTextObject.builder().text("Title").build())
+                .childBlocks(Arrays.asList(divider()))
+        ), is(notNullValue()));
+    }
+
     @Test
     public void testImage() {
         assertThat(Blocks.image(i -> i.blockId("block-id").imageUrl("https://www.example.com/")), is(notNullValue()));