Workspace transfer: custom themes ride the export/import envelope

src/core/export-envelope.ts

@@ -12,6 +12,7 @@
  * migration target — see snippet.ts / dataset.ts).
  */
 
+import type { CustomTheme } from './custom-theme';
 import type { Dataset } from './dataset';
 import type { Snippet } from './snippet';
 
@@ -24,8 +25,9 @@ export const EXPORT_ENVELOPE_VERSION = '1.0';
 
 /**
  * The downloaded file's top-level shape (spec §08 → Export envelope shape): format
- * metadata plus the two complete-record arrays. Each record keeps its own `version`
- * field unchanged.
+ * metadata plus the complete-record arrays. Each record keeps its own `version`
+ * field unchanged. `themes` is additive (always written, optional on read) so
+ * pre-theme envelopes and importers remain compatible without a format bump.
  */
 export interface ExportEnvelope {
   /** Export format version (currently `"1.0"`). */
@@ -38,6 +40,8 @@ export interface ExportEnvelope {
   snippets: Snippet[];
   /** All datasets, as complete records (each including its record `version`). */
   datasets: Dataset[];
+  /** All custom chart themes, as complete records (each including its record `version`). */
+  themes: CustomTheme[];
 }
 
 /**
@@ -50,6 +54,7 @@ export interface ExportEnvelope {
 export function buildExportEnvelope(
   snippets: ReadonlyArray<Snippet>,
   datasets: ReadonlyArray<Dataset>,
+  themes: ReadonlyArray<CustomTheme>,
   opts: { now: Date },
 ): ExportEnvelope {
   return {
@@ -58,6 +63,7 @@ export function buildExportEnvelope(
     exportedBy: 'Astrolabe',
     snippets: [...snippets],
     datasets: [...datasets],
+    themes: [...themes],
   };
 }
 
@@ -82,12 +88,21 @@ function countClause(count: number, noun: string): string {
 }
 
 /**
- * Success-toast message reporting the export counts (spec §08 → Feedback), e.g.
- * "Exported 4 snippets and 2 datasets". The dataset clause is omitted entirely when
- * there are no datasets; singular/plural wording adapts to the counts.
+ * Success-toast message reporting transfer counts (spec §08 → Feedback) for both
+ * directions, e.g. "Exported 4 snippets, 2 datasets and 1 theme" / "Imported 1
+ * snippet". The dataset and theme clauses are omitted entirely when their counts
+ * are zero; singular/plural wording adapts. One builder for export and import so
+ * a new record kind or wording change lands in both messages at once.
  */
-export function exportSummaryMessage(snippetCount: number, datasetCount: number): string {
-  const snippets = countClause(snippetCount, 'snippet');
-  if (datasetCount === 0) return `Exported ${snippets}`;
-  return `Exported ${snippets} and ${countClause(datasetCount, 'dataset')}`;
+export function transferSummaryMessage(
+  verb: 'Exported' | 'Imported',
+  snippetCount: number,
+  datasetCount: number,
+  themeCount: number,
+): string {
+  const clauses = [countClause(snippetCount, 'snippet')];
+  if (datasetCount > 0) clauses.push(countClause(datasetCount, 'dataset'));
+  if (themeCount > 0) clauses.push(countClause(themeCount, 'theme'));
+  const last = clauses.pop()!;
+  return clauses.length === 0 ? `${verb} ${last}` : `${verb} ${clauses.join(', ')} and ${last}`;
 }