Fix/elapsed days (#45)

* Fix/ incorrect calculation of elapsed_days in the revlog caused by rollback * 3.1.0-beta3
open-spaced-repetition · Nov 11, 2023 · c9d994d · c9d994d
1 parent 8154795
commit c9d994d
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Showing 7 changed files with 100 additions and 12 deletions.
diff --git a/__tests__/FSRSV4.test.ts b/__tests__/FSRSV4.test.ts
@@ -6,7 +6,7 @@ import {
   createEmptyCard,
   State,
   Grade,
-  Grades
+  Grades,
 } from "../src/fsrs";
 
 describe("initial FSRS V4", () => {
@@ -77,6 +77,9 @@ describe("FSRS V4 AC by py-fsrs", () => {
           scheduling_cards[check].log,
         );
         expect(rollbackCard).toEqual(card);
+        expect(scheduling_cards[check].log.elapsed_days).toEqual(
+          card.last_review ? now.diff(card.last_review as Date, "days") : 0,
+        );
       }
       card = scheduling_cards[rating].card;
       const ivl = card.scheduled_days;

diff --git a/__tests__/elapsed_days.test.ts b/__tests__/elapsed_days.test.ts
@@ -0,0 +1,74 @@
+// Ref:https://github.com/ishiko732/ts-fsrs/issues/44
+
+import { fsrs, FSRS, createEmptyCard, Rating, Grade } from "../src/fsrs";
+
+describe("elapsed_days", () => {
+  const f: FSRS = fsrs();
+
+  const createDue = new Date(Date.UTC(2023, 9, 18, 14, 32, 3, 370));
+  const grades: Grade[] = [
+    Rating.Good,
+    Rating.Again,
+    Rating.Again,
+    Rating.Good,
+  ];
+  let currentLog = null;
+  let index = 0;
+  let card = createEmptyCard(createDue);
+  test("first repeat[Rating.Good]", () => {
+    const firstDue = new Date(Date.UTC(2023, 10, 5, 8, 27, 2, 605));
+    const sc = f.repeat(card, firstDue);
+    currentLog = sc[grades[index]].log;
+
+    expect(currentLog.elapsed_days).toEqual(0);
+    // console.log(sc[grades[index]].log)
+    card = sc[grades[index]].card;
+    // console.log(card)
+    index += 1;
+  });
+
+  test("second repeat[Rating.Again]", () => {
+    // 2023-11-08 15:02:09.791,4.93,2023-11-05 08:27:02.605
+    const secondDue = new Date(Date.UTC(2023, 10, 8, 15, 2, 9, 791));
+    expect(card).not.toBeNull()
+    const sc = f.repeat(card, secondDue);
+
+    currentLog = sc[grades[index]].log;
+    expect(currentLog.elapsed_days).toEqual(secondDue.diff(card.last_review as Date,'days')); // 3
+    expect(currentLog.elapsed_days).toEqual(3); // 0
+    card = sc[grades[index]].card;
+    // console.log(card)
+    // console.log(currentLog)
+    index += 1;
+  });
+
+  test("third repeat[Rating.Again]", () => {
+    // 2023-11-08 15:02:30.799,4.93,2023-11-08 15:02:09.791
+    const secondDue = new Date(Date.UTC(2023, 10, 8, 15, 2, 30, 799));
+    expect(card).not.toBeNull()
+    const sc = f.repeat(card, secondDue);
+
+    currentLog = sc[grades[index]].log;
+    expect(currentLog.elapsed_days).toEqual(secondDue.diff(card.last_review as Date,'days')); // 0
+    expect(currentLog.elapsed_days).toEqual(0); // 0
+    // console.log(currentLog);
+    card = sc[grades[index]].card;
+    // console.log(card);
+    index += 1;
+  });
+
+  test("fourth repeat[Rating.Good]", () => {
+    // 2023-11-08 15:04:08.739,4.93,2023-11-08 15:02:30.799
+    const secondDue = new Date(Date.UTC(2023, 10, 8, 15, 4, 8, 739));
+    expect(card).not.toBeNull()
+    const sc = f.repeat(card, secondDue);
+
+    currentLog = sc[grades[index]].log;
+    expect(currentLog.elapsed_days).toEqual(secondDue.diff(card.last_review as Date,'days')); // 0
+    expect(currentLog.elapsed_days).toEqual(0); // 0
+    // console.log(currentLog);
+    card = sc[grades[index]].card;
+    // console.log(card);
+    index += 1;
+  })
+});
diff --git a/package.json b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ts-fsrs",
-  "version": "3.1.0-beta2",
+  "version": "3.1.0-beta3",
   "description": "ts-fsrs is a TypeScript package used to implement the Free Spaced Repetition Scheduler (FSRS) algorithm. It helps developers apply FSRS to their flashcard applications, thereby improving the user learning experience.",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

diff --git a/src/fsrs/default.ts b/src/fsrs/default.ts
@@ -30,7 +30,7 @@ export const default_w = envParams.FSRS_W || [
 ];
 export const default_enable_fuzz = envParams.FSRS_ENABLE_FUZZ || false;
 
-export const FSRSVersion: string = "3.1.0-beta2";
+export const FSRSVersion: string = "3.1.0-beta3";
 
 export const generatorParameters = (props?: Partial<FSRSParameters>): FSRSParameters => {
   return {

diff --git a/src/fsrs/fsrs.ts b/src/fsrs/fsrs.ts
@@ -107,12 +107,13 @@ export class FSRS extends FSRSAlgorithm {
     if (log.rating === Rating.Manual) {
       throw new Error("Cannot rollback a manual rating");
     }
-    let last_due, last_review, last_lapses;
+    let last_due, last_review, last_lapses, last_elapsed_days;
     switch (log.state) {
       case State.New:
         last_due = log.due;
         last_review = undefined;
         last_lapses = 0;
+        last_elapsed_days = 0;
         break;
       case State.Learning:
       case State.Relearning:
@@ -122,6 +123,10 @@ export class FSRS extends FSRSAlgorithm {
         last_lapses =
           card.lapses -
           (log.rating === Rating.Again && log.state === State.Review ? 1 : 0);
+        last_elapsed_days =
+          log.elapsed_days == 0
+            ? 0
+            : card.scheduled_days;
         break;
     }
 
@@ -130,7 +135,7 @@ export class FSRS extends FSRSAlgorithm {
       due: last_due,
       stability: log.stability,
       difficulty: log.difficulty,
-      elapsed_days: log.elapsed_days,
+      elapsed_days: log.last_elapsed_days,
       scheduled_days: log.scheduled_days,
       reps: Math.max(0, card.reps - 1),
       lapses: Math.max(0, last_lapses),
@@ -152,7 +157,8 @@ export class FSRS extends FSRSAlgorithm {
       due: card.due,
       stability: card.stability,
       difficulty: card.difficulty,
-      elapsed_days: card.elapsed_days,
+      elapsed_days: 0,
+      last_elapsed_days: card.elapsed_days,
       scheduled_days: card.scheduled_days,
       review: now,
     };

diff --git a/src/fsrs/models.ts b/src/fsrs/models.ts
@@ -28,6 +28,7 @@ export interface ReviewLog {
   stability: number;
   difficulty: number;
   elapsed_days: number;
+  last_elapsed_days: number;
   scheduled_days: number;
   review: Date;
 }

diff --git a/src/fsrs/scheduler.ts b/src/fsrs/scheduler.ts
@@ -7,7 +7,7 @@ export class SchedulingCard {
   good: Card;
   easy: Card;
   last_review: Date;
-  elapsed_days: number;
+  last_elapsed_days: number;
 
   private copy(card: Card): Card {
     return {
@@ -17,7 +17,7 @@ export class SchedulingCard {
 
   constructor(card: Card, now: Date) {
     this.last_review = card.last_review || card.due;
-    this.elapsed_days = card.elapsed_days;
+    this.last_elapsed_days = card.elapsed_days;
     card.elapsed_days =
       card.state === State.New ? 0 : now.diff(card.last_review as Date, "days"); //相距时间
     card.last_review = now; // 上次复习时间
@@ -80,7 +80,8 @@ export class SchedulingCard {
           due: this.last_review,
           stability: card.stability,
           difficulty: card.difficulty,
-          elapsed_days: this.elapsed_days,
+          elapsed_days: card.elapsed_days,
+          last_elapsed_days: this.last_elapsed_days,
           scheduled_days: card.scheduled_days,
           review: now,
         },
@@ -93,7 +94,8 @@ export class SchedulingCard {
           due: this.last_review,
           stability: card.stability,
           difficulty: card.difficulty,
-          elapsed_days: this.elapsed_days,
+          elapsed_days: card.elapsed_days,
+          last_elapsed_days: this.last_elapsed_days,
           scheduled_days: card.scheduled_days,
           review: now,
         },
@@ -106,7 +108,8 @@ export class SchedulingCard {
           due: this.last_review,
           stability: card.stability,
           difficulty: card.difficulty,
-          elapsed_days: this.elapsed_days,
+          elapsed_days: card.elapsed_days,
+          last_elapsed_days: this.last_elapsed_days,
           scheduled_days: card.scheduled_days,
           review: now,
         },
@@ -119,7 +122,8 @@ export class SchedulingCard {
           due: this.last_review,
           stability: card.stability,
           difficulty: card.difficulty,
-          elapsed_days: this.elapsed_days,
+          elapsed_days: card.elapsed_days,
+          last_elapsed_days: this.last_elapsed_days,
           scheduled_days: card.scheduled_days,
           review: now,
         },