feat(websocket): Enhance patch functionality to support pinning operations

Author: takker99

websocket/patch.ts

@@ -5,6 +5,7 @@ import { push, type PushError, type PushOptions } from "./push.ts";
 import { suggestUnDupTitle } from "./suggestUnDupTitle.ts";
 import type { Result } from "option-t/plain_result";
 import type { Socket } from "socket.io-client";
+import { pinNumber } from "./pin.ts";
 
 export interface PatchMetadata extends Page {
   /** Number of retry attempts for page modification
@@ -25,17 +26,27 @@ export interface PatchMetadata extends Page {
  * @param lines - Current page lines
  * @param metadata - Current page metadata
  * @returns one of the following or a {@linkcode Promise} resolving to one:
- * - `(string | { text: string; })[]`: New page content
+ * - `NewPageContent["lines"]`: New page lines
+ * - `NewPageContent`: New page content with optional pinning operation
  * - `[]`: Delete the page
  * - `undefined`: Abort modification
  */
 export type MakePatchFn = (
   lines: BaseLine[],
   metadata: PatchMetadata,
 ) =>
-  | (string | { text: string })[]
+  | NewPageContent["lines"]
+  | NewPageContent
   | undefined
-  | Promise<(string | { text: string })[] | undefined>;
+  | Promise<NewPageContent["lines"] | NewPageContent | undefined>;
+
+export interface NewPageContent {
+  /** New page lines */
+  lines: (string | { text: string })[];
+
+  /** Whether to pin the page */
+  pin?: boolean;
+}
 
 export type PatchOptions = PushOptions;
 
@@ -48,6 +59,8 @@ export type PatchOptions = PushOptions;
  * 4. Handles errors (e.g., duplicate titles)
  * 5. Retries on conflicts
  *
+ * This function also can pin/unpin pages by setting the `pin` property in the return of `update`.
+ *
  * @param project Project ID containing the target page
  * @param title Title of the page to modify
  * @param update Function to generate new content
@@ -76,10 +89,23 @@ export const patch = (
         }) as Change[] | [DeletePageChange];
       }
       const pending = update(page.lines, { ...page, attempts });
-      const newLines = pending instanceof Promise ? await pending : pending;
-      if (newLines === undefined) return [];
+      const newContent = pending instanceof Promise ? await pending : pending;
+      if (newContent === undefined) return [];
+      const [newLines, pin] = Array.isArray(newContent)
+        ? ([newContent, undefined] as const)
+        : ([newContent.lines, newContent.pin] as const);
+
       if (newLines.length === 0) return [{ deleted: true }];
-      return [...makeChanges(page, newLines, page.userId)];
+
+      const changes = page.lines === newLines
+        ? []
+        : [...makeChanges(page, newLines, page.userId)];
+      if (
+        pin !== undefined && ((pin && page.pin === 0) || (!pin && page.pin > 0))
+      ) {
+        changes.push({ pin: pin ? pinNumber() : 0 });
+      }
+      return changes;
     },
     options,
   );

websocket/pin.ts

@@ -22,6 +22,9 @@ export interface PinOptions extends PushOptions {
  * based on the current timestamp to maintain a stable order.
  * Higher pin numbers appear first in the list.
  *
+ * > [!NOTE]
+ * > If you want to modify the page content while pinning it, {@linkcode patch} is more suitable.
+ *
  * @param project - Project containing the target page
  * @param title - Title of the page to pin
  * @param options - Optional settings:
@@ -58,6 +61,9 @@ export interface UnPinOptions extends PushOptions {}
  *
  * This sets the page's pin number to `0`, which effectively unpins it.
  *
+ * > [!NOTE]
+ * > If you want to modify the page content while unpinning it, {@linkcode patch} is more suitable.
+ *
  * @param project - Project containing the target page
  * @param title - Title of the page to unpin
  * @returns A {@linkcode Promise} that resolves to a {@linkcode Result} containing: