Files
classroomio/apps/api/src/services/course/slug.ts
T

43 lines
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TypeScript

import { AppError, ErrorCodes } from '@api/utils/errors';
import { getTakenItemSlugs } from '@cio/db/queries/course';
import { SLUG_REGEX, resolveSlugCollision, slugifyTitle } from '@cio/utils/validation';
/**
* Resolve an item (lesson or exercise) slug for a given course:
* - If `requestedSlug` is provided, validate it and reject if already taken (excluding `ignoreItemId`).
* - Otherwise derive a slug from `title` and append `-2`, `-3`, ... until free.
*
* Uniqueness is enforced across the union of `lesson.slug` and `exercise.slug` per course.
*/
export async function resolveItemSlug(params: {
courseId: string;
title: string;
requestedSlug?: string;
ignoreItemSlug?: string;
}): Promise<string> {
const { courseId, title, requestedSlug, ignoreItemSlug } = params;
const takenSlugs = await getTakenItemSlugs(courseId);
if (ignoreItemSlug) {
takenSlugs.delete(ignoreItemSlug);
}
if (requestedSlug) {
if (!SLUG_REGEX.test(requestedSlug)) {
throw new AppError(
'Slug must be lowercase letters, numbers, and single dashes',
ErrorCodes.VALIDATION_ERROR,
400,
'slug'
);
}
if (takenSlugs.has(requestedSlug)) {
throw new AppError('Slug is already in use in this course', ErrorCodes.SLUG_IN_USE, 409, 'slug');
}
return requestedSlug;
}
const base = slugifyTitle(title);
return resolveSlugCollision(base, takenSlugs);
}