fix(scratch-vm): 拡張機能の HAT/EVENT ブロックを modern Blockly で帽子型に描画

.claude/rules/scratch-vm/development.md

@@ -216,6 +216,7 @@ The mesh v2 extension uses AWS AppSync for real-time collaboration:
 | `src/blocks/scratch3_operators.js` | regex support | operator_contains で正規表現マッチングをサポート |
 | `src/engine/comment.js` | toXML modernization | Blockly v12 対応: `pinned="${!minimized}"` (cherry-pick from upstream spork@29bdbd1fe) + (0,0) 時の x/y 属性省略 (Smalruby 独自) |
 | `src/engine/runtime.js` | toolboxitemid for extension categories | Blockly v12 対応: 拡張機能のカテゴリ XML に `toolboxitemid` 属性を追加。Blockly v12 の ContinuousToolbox は `toolboxitemid` から id を読むため、未指定だと `blockly-XXX` の auto-id が StatusIndicatorLabel.extensionId に伝搬し、`!` 接続モーダルが拡張機能を見つけられず scanning で固まる |
+| `src/engine/runtime.js` | extension hat shape (modern Blockly) | Blockly v12 対応: 拡張機能の HAT/EVENT ブロックの blockJSON に `shape_hat` extension を付与。modern Blockly は `block.hat === 'cap'`（= `shape_hat` extension）でのみ帽子型を描画し、`ADD_START_HATS` は既定 false。未付与だと甲子園 `connect_game` や micro:bit/顔認識の `when ...` ブロックが帽子型にならず平らな上端で描画される |
 
 ### 関連ファイル
 

packages/scratch-vm/src/engine/runtime.js

@@ -1156,6 +1156,16 @@ class Runtime extends EventEmitter {
             }
             blockJSON.outputShape = ScratchBlocksConstants.OUTPUT_SHAPE_SQUARE;
             blockJSON.nextStatement = null; // null = available connection; undefined = terminal
+            // === Smalruby: Start of extension hat shape (modern Blockly) ===
+            // In modern Blockly (scratch-blocks v2) the cap-hat shape is only
+            // drawn when the block carries the `shape_hat` extension (which sets
+            // block.hat = 'cap'); a missing previousConnection alone is no longer
+            // enough (ADD_START_HATS defaults to false). The built-in event blocks
+            // declare extensions: ['colours_event', 'shape_hat'], so mirror that
+            // here for extension HAT/EVENT blocks (e.g. koshien connect_game,
+            // micro:bit/face-sensing "when ..." blocks) so they render as hats.
+            blockJSON.extensions = (blockJSON.extensions || []).concat('shape_hat');
+            // === Smalruby: End of extension hat shape (modern Blockly) ===
             break;
         case BlockType.CONDITIONAL:
         case BlockType.LOOP:

packages/scratch-vm/test/unit/runtime_extension_hat_shape.js

@@ -0,0 +1,54 @@
+const test = require('tap').test;
+const Runtime = require('../../src/engine/runtime');
+const BlockType = require('../../src/extension-support/block-type');
+
+const categoryInfo = {
+    id: 'testcat',
+    name: 'Test',
+    color1: '#111111',
+    color2: '#222222',
+    color3: '#333333',
+    blocks: [],
+    customFieldTypes: {},
+    menus: [],
+    menuInfo: {}
+};
+
+const convert = (rt, blockInfo) => rt._convertForScratchBlocks(blockInfo, categoryInfo);
+
+// Modern Blockly (scratch-blocks v2) only draws the cap-hat shape for blocks
+// carrying the `shape_hat` extension. Verify the extension-block conversion adds
+// it for HAT/EVENT blocks (so e.g. koshien connect_game renders as a hat) and
+// does not turn COMMAND blocks into hats.
+test('extension HAT/EVENT blocks get the shape_hat extension', t => {
+    const rt = new Runtime();
+
+    const hat = convert(rt, {opcode: 'whenX', blockType: BlockType.HAT, text: 'when X', arguments: {}});
+    t.ok(hat.json.extensions, 'HAT has an extensions array');
+    t.ok(hat.json.extensions.includes('shape_hat'), 'HAT has shape_hat');
+    t.equal(hat.json.previousStatement, undefined, 'HAT has no previous connection');
+    t.equal(hat.json.nextStatement, null, 'HAT has a next connection');
+
+    const event = convert(rt, {opcode: 'onX', blockType: BlockType.EVENT, text: 'on X', arguments: {}});
+    t.ok(event.json.extensions.includes('shape_hat'), 'EVENT has shape_hat');
+
+    const cmd = convert(rt, {opcode: 'doX', blockType: BlockType.COMMAND, text: 'do X', arguments: {}});
+    t.notOk(
+        cmd.json.extensions && cmd.json.extensions.includes('shape_hat'),
+        'COMMAND does not get shape_hat'
+    );
+    t.equal(cmd.json.previousStatement, null, 'COMMAND keeps its previous connection');
+
+    // a HAT with an icon keeps the icon extension AND gains shape_hat
+    const hatWithIcon = convert(rt, {
+        opcode: 'whenIcon',
+        blockType: BlockType.HAT,
+        text: 'when icon',
+        arguments: {},
+        blockIconURI: 'data:image/png;base64,AAAA'
+    });
+    t.ok(hatWithIcon.json.extensions.includes('shape_hat'), 'icon HAT has shape_hat');
+    t.ok(hatWithIcon.json.extensions.includes('scratch_extension'), 'icon HAT keeps scratch_extension');
+
+    t.end();
+});