Fix guide editor issues 4-10

core/blocks.js

@@ -0,0 +1,41 @@
+'use strict';
+
+const BLOCK_KIND_ORDER = { text: 0, code: 1, table: 2 };
+
+function blockText(block) {
+  if (!block || typeof block !== 'object') return '';
+  for (const key of ['code', 'text', 'body', 'value', 'content']) {
+    const value = block[key];
+    if (value != null && value !== '') return String(value);
+  }
+  return '';
+}
+
+function orderedBlocks(step) {
+  const blocks = [];
+  for (const tb of step.textBlocks || []) {
+    blocks.push({ kind: 'text', ...tb });
+  }
+  for (const cb of step.codeBlocks || []) {
+    blocks.push({ kind: 'code', ...cb, code: blockText(cb) });
+  }
+  for (const tbl of step.tableBlocks || []) {
+    blocks.push({ kind: 'table', ...tbl });
+  }
+  return blocks.sort((a, b) => (
+    (Number.isFinite(a.order) ? a.order : 0) - (Number.isFinite(b.order) ? b.order : 0)
+    || (BLOCK_KIND_ORDER[a.kind] - BLOCK_KIND_ORDER[b.kind])
+    || String(a.id || '').localeCompare(String(b.id || ''))
+  ));
+}
+
+function nextBlockOrder(step) {
+  return orderedBlocks(step).reduce((max, block) => Math.max(max, Number.isFinite(block.order) ? block.order : 0), 0) + 1;
+}
+
+module.exports = {
+  BLOCK_KIND_ORDER,
+  blockText,
+  orderedBlocks,
+  nextBlockOrder,
+};