Optional with and typesafe return

[ChoaibMouhrachAkera]

I have the following method:

public async all(options?: { course?: boolean }) {
    const chapters = await this.db.query.chaptersTable.findMany({
      where: and(...this.getBaseConditions()),
      with: {
        course: options?.course === true || undefined,
      },
    });

    return chapters.map((chapter) => {
      return {
        chapter: new Chapter(chapter, this.db),
        course:
          options?.course === true
            ? new Course(chapter.course, this.db)
            : undefined,
      };
    });
  }

Problem:

I want the return type to include course when I pass true for the course parameter, and to exclude it (i.e., return undefined) when no value is passed. However, when passing true | undefined to the with attribute, it doesn't make the course optional—it just sets the type to true | undefined. This issue also affects the return type, as it doesn't reflect the optional nature of course.

Expected Behavior:

• When options?.course is true, the course should be included in the returned object.
• When options?.course is not passed (or is undefined), the course should be excluded from the returned object.

How can I ensure the return type is correctly adjusted to reflect this optional course property?