feat(core): joinTextWithEntities method in utils

packages/core/src/highlevel/utils/entities.test.ts

@@ -0,0 +1,61 @@
+import { describe, expect, it } from 'vitest'
+
+import { tl } from '@mtcute/tl'
+
+import { joinTextWithEntities } from './entities.js'
+
+const createEntity = (offset: number, length: number): tl.TypeMessageEntity => {
+    return {
+        _: 'messageEntityBold',
+        offset,
+        length,
+    }
+}
+
+describe('joinTextWithEntities', () => {
+    it('should join text with entities using a string delimiter', () => {
+        expect(
+            joinTextWithEntities(
+                [
+                    { text: 'foo bar baz', entities: [createEntity(0, 3), createEntity(4, 3), createEntity(8, 3)] },
+                    { text: 'egg spam', entities: [createEntity(4, 4)] },
+                    { text: 'very spam', entities: [createEntity(0, 4)] },
+                ],
+                ' 🚀 ',
+            ),
+        ).toEqual({
+            text: 'foo bar baz 🚀 egg spam 🚀 very spam',
+            entities: [
+                createEntity(0, 3),
+                createEntity(4, 3),
+                createEntity(8, 3),
+                createEntity(19, 4),
+                createEntity(27, 4),
+            ],
+        })
+    })
+
+    it('should join text with entities using a TextWithEntities delimiter', () => {
+        expect(
+            joinTextWithEntities(
+                [
+                    { text: 'foo bar baz', entities: [createEntity(0, 3), createEntity(4, 3), createEntity(8, 3)] },
+                    { text: 'egg spam', entities: [createEntity(4, 4)] },
+                    { text: 'very spam', entities: [createEntity(0, 4)] },
+                ],
+                { text: ' 🚀 ', entities: [createEntity(1, 2)] },
+            ),
+        ).toEqual({
+            text: 'foo bar baz 🚀 egg spam 🚀 very spam',
+            entities: [
+                createEntity(0, 3),
+                createEntity(4, 3),
+                createEntity(8, 3),
+                createEntity(12, 2),
+                createEntity(19, 4),
+                createEntity(24, 2),
+                createEntity(27, 4),
+            ],
+        })
+    })
+})

packages/core/src/highlevel/utils/entities.ts

@@ -0,0 +1,62 @@
+import { tl } from '@mtcute/tl'
+
+import { TextWithEntities } from '../types/misc/entities.js'
+
+/**
+ * Join multiple text parts with entities into a single text with entities,
+ * adjusting the entities' offsets accordingly.
+ *
+ * @param parts  List of text parts with entities
+ * @param delim  Delimiter to insert between parts
+ * @returns  A single text with entities
+ * @example
+ *
+ * ```ts
+ * const scoreboardText = joinTextWithEntities(
+ *   apiResult.scoreboard.map((entry) => html`<b>${entry.name}</b>: ${entry.score}`),
+ *   html`<br>`
+ * )
+ * await tg.sendText(chatId, html`<b>scoreboard:</b><br><br>${scoreboardText}`)
+ * ```
+ */
+export function joinTextWithEntities(
+    parts: (string | TextWithEntities)[],
+    delim: string | TextWithEntities = '',
+): TextWithEntities {
+    const textParts: string[] = []
+    const newEntities: tl.TypeMessageEntity[] = []
+
+    let position = 0
+
+    if (typeof delim === 'string') {
+        delim = { text: delim }
+    }
+
+    const pushPart = (part: TextWithEntities) => {
+        textParts.push(part.text)
+        const entitiesOffset = position
+        position += part.text.length
+
+        if (part.entities) {
+            for (const entity of part.entities) {
+                newEntities.push({
+                    ...entity,
+                    offset: entity.offset + entitiesOffset,
+                })
+            }
+        }
+    }
+
+    for (const part of parts) {
+        if (position > 0) {
+            pushPart(delim)
+        }
+
+        pushPart(typeof part === 'string' ? { text: part } : part)
+    }
+
+    return {
+        text: textParts.join(''),
+        entities: newEntities,
+    }
+}

packages/core/src/highlevel/utils/index.ts

@@ -1,5 +1,6 @@
 // todo: merge this with the main utils dir?
 
+export * from './entities.js'
 export * from './file-utils.js'
 export * from './inline-utils.js'
 export * from './inspectable.js'