pref/adjusting get_retrievability (#83)

* pref/adjusting the return type in retrievability

* Number(r) -> r

* stability -> Math.round(stability)

Keep the synchronous code consistent:
https://github.com/open-spaced-repetition/fsrs4anki/blob/c6ce3f197fb403ccb7cb5290d5a59fd818ad11cb/fsrs4anki_scheduler.js#L138-L144

* _now -> now

* 3.5.7

__tests__/FSRSV4.test.ts

@@ -114,11 +114,17 @@ describe("get retrievability", () => {
  });
 
  test("return retrievability percentage for review cards", () => {
- const card = createEmptyCard();
- const sc = fsrs.repeat(card, new Date());
- const r = [undefined, undefined, undefined, "100.00%"];
- Grades.forEach((grade,index) => {
- expect(fsrs.get_retrievability(sc[grade].card, new Date())).toBe(r[index]);
+ const card = createEmptyCard("2023-12-01 04:00:00");
+ const sc = fsrs.repeat(card, "2023-12-01 04:05:00");
+ const r = [undefined, undefined, undefined, "90.00%"];
+ const r_number = [undefined, undefined, undefined, 0.9];
+ Grades.forEach((grade, index) => {
+ expect(fsrs.get_retrievability(sc[grade].card, sc[grade].card.due)).toBe(
+ r[index],
+ );
+ expect(
+ fsrs.get_retrievability(sc[grade].card, sc[grade].card.due, false),
+ ).toBe(r_number[index]);
  });
  });
 });

package.json

@@ -1,6 +1,6 @@
 {
  "name": "ts-fsrs",
- "version": "3.5.6",
+ "version": "3.5.7",
  "description": "ts-fsrs is a ES modules package based on TypeScript, used to implement the Free Spaced Repetition Scheduler (FSRS) algorithm. It helps developers apply FSRS to their flashcard applications, there by improving the user learning experience.",
  "main": "dist/index.cjs",
  "umd": "dist/index.umd.js",

src/fsrs/default.ts

@@ -9,7 +9,7 @@ export const default_w = [
 ];
 export const default_enable_fuzz = false;
 
-export const FSRSVersion: string = "3.5.6";
+export const FSRSVersion: string = "3.5.7";
 
 export const generatorParameters = (
  props?: Partial<FSRSParameters>,

src/fsrs/fsrs.ts

@@ -159,20 +159,29 @@ export class FSRS extends FSRSAlgorithm {
  }
  }
 
- get_retrievability = (
+ /**
+ * Get the retrievability of the card
+ * @param card Card to be processed
+ * @param now Current time or scheduled time
+ * @param format default:true , Convert the result to another type. (Optional)
+ * @returns The retrievability of the card,if format is true, the result is a string, otherwise it is a number
+ */
+ get_retrievability<T extends boolean>(
  card: CardInput | Card,
- now: Date,
- ): undefined | string => {
+ now: DateInput,
+ format: T = true as T,
+ ): undefined | (T extends true ? string : number) {
  const processedCard = this.preProcessCard(card);
  now = this.preProcessDate(now);
  if (processedCard.state !== State.Review) {
  return undefined;
  }
  const t = Math.max(now.diff(processedCard.last_review as Date, "days"), 0);
- return (
- (this.forgetting_curve(t, processedCard.stability) * 100).toFixed(2) + "%"
- );
- };
+ const r = this.forgetting_curve(t, Math.round(processedCard.stability));
+ return (format ? `${(r * 100).toFixed(2)}%` : r) as T extends true
+ ? string
+ : number;
+ }
 
  /**
  *
@@ -420,4 +429,4 @@ export class FSRS extends FSRSAlgorithm {
  */
 export const fsrs = (params?: Partial<FSRSParameters>) => {
  return new FSRS(params || {});
-};
+};