chore(web): translate alt text (#10922)

* chore(web): translate image alt text

* fix: capitalize translations, improve unit test

* fix: unit testing against the actual en.json file

* fix: use derived store to generate alt text

web/src/lib/utils/thumbnail-util.spec.ts

@@ -0,0 +1,68 @@
+import { getAltText } from '$lib/utils/thumbnail-util';
+import { AssetTypeEnum, type AssetResponseDto } from '@immich/sdk';
+import { init, register, waitLocale } from 'svelte-i18n';
+
+describe('getAltText', () => {
+  beforeAll(async () => {
+    await init({ fallbackLocale: 'en-US' });
+    register('en-US', () => import('$lib/i18n/en.json'));
+    await waitLocale('en-US');
+  });
+
+  it('defaults to the description, if available', () => {
+    const asset = {
+      exifInfo: { description: 'description' },
+    } as AssetResponseDto;
+
+    getAltText.subscribe((fn) => {
+      expect(fn(asset)).toEqual('description');
+    });
+  });
+
+  it('includes the city and country', () => {
+    const asset = {
+      exifInfo: { city: 'city', country: 'country' },
+      localDateTime: '2024-01-01T12:00:00.000Z',
+    } as AssetResponseDto;
+
+    getAltText.subscribe((fn) => {
+      expect(fn(asset)).toEqual('Image taken in city, country on January 1, 2024');
+    });
+  });
+
+  // convert the people tests into an it.each
+  it.each([
+    [[{ name: 'person' }], 'Image taken with person on January 1, 2024'],
+    [[{ name: 'person1' }, { name: 'person2' }], 'Image taken with person1 and person2 on January 1, 2024'],
+    [
+      [{ name: 'person1' }, { name: 'person2' }, { name: 'person3' }],
+      'Image taken with person1, person2, and person3 on January 1, 2024',
+    ],
+    [
+      [{ name: 'person1' }, { name: 'person2' }, { name: 'person3' }, { name: 'person4' }],
+      'Image taken with person1, person2, and 2 others on January 1, 2024',
+    ],
+  ])('includes people, correctly formatted', (people, expected) => {
+    const asset = {
+      localDateTime: '2024-01-01T12:00:00.000Z',
+      people,
+    } as AssetResponseDto;
+
+    getAltText.subscribe((fn) => {
+      expect(fn(asset)).toEqual(expected);
+    });
+  });
+
+  it('handles videos, location, people, and date', () => {
+    const asset = {
+      exifInfo: { city: 'city', country: 'country' },
+      localDateTime: '2024-01-01T12:00:00.000Z',
+      people: [{ name: 'person1' }, { name: 'person2' }, { name: 'person3' }, { name: 'person4' }, { name: 'person5' }],
+      type: AssetTypeEnum.Video,
+    } as AssetResponseDto;
+
+    getAltText.subscribe((fn) => {
+      expect(fn(asset)).toEqual('Video taken in city, country with person1, person2, and 3 others on January 1, 2024');
+    });
+  });
+});

web/src/lib/utils/thumbnail-util.ts

@@ -1,4 +1,6 @@
-import type { AssetResponseDto } from '@immich/sdk';
+import { AssetTypeEnum, type AssetResponseDto } from '@immich/sdk';
+import { t } from 'svelte-i18n';
+import { derived } from 'svelte/store';
 import { fromLocalDateTime } from './timeline-util';
 
 /**
@@ -35,29 +37,39 @@ export function getThumbnailSize(assetCount: number, viewWidth: number): number
   return 300;
 }
 
-export function getAltText(asset: AssetResponseDto) {
-  if (asset.exifInfo?.description) {
-    return asset.exifInfo.description;
-  }
+export const getAltText = derived(t, ($t) => {
+  return (asset: AssetResponseDto) => {
+    if (asset.exifInfo?.description) {
+      return asset.exifInfo.description;
+    }
 
-  let altText = 'Image taken';
-  if (asset.exifInfo?.city && asset.exifInfo.country) {
-    altText += ` in ${asset.exifInfo.city}, ${asset.exifInfo.country}`;
-  }
+    let altText = $t('image_taken', { values: { isVideo: asset.type === AssetTypeEnum.Video } });
 
-  const names = asset.people?.filter((p) => p.name).map((p) => p.name) ?? [];
-  if (names.length == 1) {
-    altText += ` with ${names[0]}`;
-  }
-  if (names.length > 1 && names.length <= 3) {
-    altText += ` with ${names.slice(0, -1).join(', ')} and ${names.at(-1)}`;
-  }
-  if (names.length > 3) {
-    altText += ` with ${names.slice(0, 2).join(', ')}, and ${names.length - 2} others`;
-  }
+    if (asset.exifInfo?.city && asset.exifInfo?.country) {
+      const placeText = $t('image_alt_text_place', {
+        values: { city: asset.exifInfo.city, country: asset.exifInfo.country },
+      });
+      altText += ` ${placeText}`;
+    }
 
-  const date = fromLocalDateTime(asset.localDateTime).toLocaleString({ dateStyle: 'long' });
-  altText += ` on ${date}`;
+    const names = asset.people?.filter((p) => p.name).map((p) => p.name) ?? [];
+    if (names.length > 0) {
+      const namesText = $t('image_alt_text_people', {
+        values: {
+          count: names.length,
+          person1: names[0],
+          person2: names[1],
+          person3: names[2],
+          others: names.length > 3 ? names.length - 2 : 0,
+        },
+      });
+      altText += ` ${namesText}`;
+    }
 
-  return altText;
-}
+    const date = fromLocalDateTime(asset.localDateTime).toLocaleString({ dateStyle: 'long' });
+    const dateText = $t('image_alt_text_date', { values: { date } });
+    altText += ` ${dateText}`;
+
+    return altText;
+  };
+});