feat(super-editor): resolve default fontSize in get_content blocks response

Author: tupizz

packages/document-api/src/contract/operation-definitions.ts

@@ -151,7 +151,7 @@ export const INTENT_GROUP_META: Record<string, IntentGroupMeta> = {
       'IMPORTANT: After a markdown insert, analyze the document context (what kind of document, how titles and body text are styled) and follow up with ONE superdoc_mutations call to format inserted blocks so they look like they belong. ' +
       'Each format.apply step accepts "inline" (fontFamily, fontSize, bold, underline, color), "alignment", and "scope" in the same step. ' +
       'Use scope: "block" so formatting covers the entire paragraph. ' +
-      'ONLY set inline properties that are explicitly shown in the existing get_content blocks. If blocks do not show fontSize, do NOT set fontSize (it inherits the document default). Do NOT invent values — mirror exactly what the document blocks show. ' +
+      'Copy the exact property values from the existing get_content blocks (fontFamily, fontSize, color, alignment, bold, underline). Do NOT invent values — use what the blocks show. ' +
       'Also supports replace, delete, and undo/redo. For replace and delete, pass a "ref" from superdoc_search or superdoc_get_content blocks. ' +
       'A search ref covers only the matched substring; a block ref covers the entire block text, so use block refs when rewriting or shortening whole paragraphs. ' +
       'Refs expire after any mutation; always re-search before the next edit. ' +

packages/sdk/tools/prompt-templates/system-prompt-core.md

@@ -151,23 +151,13 @@ superdoc_edit({action: "insert", type: "markdown",
 
 **Step 3: Format ALL inserted blocks in ONE superdoc_mutations call.** Each format.apply step accepts `inline`, `alignment`, and `scope: "block"`.
 
-Use `scope: "block"` so the formatting covers the entire paragraph (not just the matched text). The text pattern only needs to identify which block.
+Use `scope: "block"` so formatting covers the entire paragraph (not just the matched text). The text pattern only needs to identify which block. Copy the exact property values from the existing blocks in the get_content response. Do NOT invent values.
 
-ONLY include inline properties that are explicitly present in the existing blocks. If the document blocks don't show `fontSize`, do NOT set fontSize (it will inherit the document's default, which is correct). If they don't show `bold`, don't set bold. Mirror exactly what you see, nothing more. Inventing values (like assuming fontSize: 12) causes mismatches.
-
-Example: document blocks show fontFamily and color but NO fontSize, titles are centered:
-```
-superdoc_mutations({action: "apply", atomic: true, steps: [
-  {id: "f1", op: "format.apply", where: {by: "select", select: {type: "text", pattern: "Executive Summary"}, require: "first"}, args: {inline: {fontFamily: "Times New Roman, serif", color: "#000000"}, alignment: "center", scope: "block"}},
-  {id: "f2", op: "format.apply", where: {by: "select", select: {type: "text", pattern: "This agreement sets forth"}, require: "first"}, args: {inline: {fontFamily: "Times New Roman, serif", color: "#000000"}, scope: "block"}}
-]})
-```
-
-Example: document blocks explicitly show fontSize: 12, titles are centered and underlined:
+Example: document blocks show fontFamily, fontSize: 10, color, titles centered:
 ```
 superdoc_mutations({action: "apply", atomic: true, steps: [
-  {id: "f1", op: "format.apply", where: {by: "select", select: {type: "text", pattern: "Executive Summary"}, require: "first"}, args: {inline: {fontFamily: "Times New Roman, serif", fontSize: 12, underline: true}, alignment: "center", scope: "block"}},
-  {id: "f2", op: "format.apply", where: {by: "select", select: {type: "text", pattern: "This agreement sets forth"}, require: "first"}, args: {inline: {fontFamily: "Times New Roman, serif", fontSize: 12, color: "#000000"}, alignment: "justify", scope: "block"}}
+  {id: "f1", op: "format.apply", where: {by: "select", select: {type: "text", pattern: "Executive Summary"}, require: "first"}, args: {inline: {fontFamily: "Times New Roman, serif", fontSize: 10, color: "#000000"}, alignment: "center", scope: "block"}},
+  {id: "f2", op: "format.apply", where: {by: "select", select: {type: "text", pattern: "This agreement sets forth"}, require: "first"}, args: {inline: {fontFamily: "Times New Roman, serif", fontSize: 10, color: "#000000"}, scope: "block"}}
 ]})
 ```
 

packages/super-editor/src/editors/v1/document-api-adapters/plan-engine/blocks-wrappers.ts

@@ -35,6 +35,7 @@ import { requireEditorCommand, rejectTrackedMode } from '../helpers/mutation-hel
 import { executeDomainCommand } from './plan-wrappers.js';
 import { getRevision } from './revision-tracker.js';
 import { encodeV4Ref } from '../story-runtime/story-ref-codec.js';
+import { readTranslatedLinkedStyles } from '../../core/parts/adapters/styles-read.js';
 
 // ---------------------------------------------------------------------------
 // Constants
@@ -66,10 +67,36 @@ function extractTextPreview(node: ProseMirrorNode): string | null {
 
 const HEADING_PATTERN = /^Heading(\d)$/;
 
+/**
+ * Resolve the document's default font size (in points) from the style catalog.
+ * Falls back through: Normal style rPr → docDefaults rPr → undefined.
+ * OOXML stores fontSize as half-points (w:sz val), so we divide by 2.
+ */
+function resolveDefaultFontSizePt(editor: Editor): number | undefined {
+  const styleProps = readTranslatedLinkedStyles(editor);
+  if (!styleProps) return undefined;
+
+  // Try Normal style first
+  const normalStyle = styleProps.styles?.['Normal'];
+  const normalFontSize = normalStyle?.runProperties?.fontSize;
+  if (typeof normalFontSize === 'number') return normalFontSize / 2;
+
+  // Fall back to docDefaults
+  const defaultFontSize = styleProps.docDefaults?.runProperties?.fontSize;
+  if (typeof defaultFontSize === 'number') return defaultFontSize / 2;
+
+  return undefined;
+}
+
 /**
  * Extract key formatting from a block node's first text run marks.
+ * When defaultFontSizePt is provided, it's used as fallback when the
+ * inline marks don't specify a fontSize (common for inherited styles).
  */
-function extractBlockFormatting(node: ProseMirrorNode): {
+function extractBlockFormatting(
+  node: ProseMirrorNode,
+  defaultFontSizePt?: number,
+): {
   styleId?: string | null;
   fontFamily?: string;
   fontSize?: number;
@@ -126,7 +153,7 @@ function extractBlockFormatting(node: ProseMirrorNode): {
   return {
     ...(styleId ? { styleId } : {}),
     ...(fontFamily ? { fontFamily } : {}),
-    ...(fontSize !== undefined ? { fontSize } : {}),
+    ...((fontSize ?? defaultFontSizePt) !== undefined ? { fontSize: fontSize ?? defaultFontSizePt } : {}),
     ...(bold ? { bold } : {}),
     ...(underline ? { underline } : {}),
     ...(color ? { color } : {}),
@@ -240,6 +267,9 @@ export function blocksListWrapper(editor: Editor, input?: BlocksListInput): Bloc
 
   const rev = getRevision(editor);
 
+  // Resolve document's default fontSize once for all blocks
+  const defaultFontSizePt = resolveDefaultFontSizePt(editor);
+
   const blocks: BlockListEntry[] = paged.map((candidate, i) => {
     const textLength = computeTextContentLength(candidate.node);
     const ref =
@@ -261,7 +291,7 @@ export function blocksListWrapper(editor: Editor, input?: BlocksListInput): Bloc
       nodeType: candidate.nodeType,
       textPreview: extractTextPreview(candidate.node),
       isEmpty: textLength === 0,
-      ...extractBlockFormatting(candidate.node),
+      ...extractBlockFormatting(candidate.node, defaultFontSizePt),
       ...(ref ? { ref } : {}),
     };
   });