feat(ts): add formatChat util

Author: jhen0409

src/__tests__/chat.test.ts

@@ -0,0 +1,61 @@
+import { formatChat } from '../chat'
+
+describe('formatChat', () => {
+  it('should format chat messages', () => {
+    const messages = [
+      {
+        role: 'user',
+        content: 'Hello, world!',
+      },
+      {
+        role: 'bot',
+        content: [
+          {
+            text: 'Hello, user!',
+          },
+          {
+            text: 'How are you?',
+          },
+        ],
+      },
+    ]
+
+    const expected = [
+      {
+        role: 'user',
+        content: 'Hello, world!',
+      },
+      {
+        role: 'bot',
+        content: 'Hello, user!\nHow are you?',
+      },
+    ]
+
+    expect(formatChat(messages)).toEqual(expected)
+  })
+
+  it('should throw an error if the content is missing', () => {
+    const messages = [
+      {
+        role: 'user',
+      },
+    ]
+
+    expect(() => formatChat(messages)).toThrowError(
+      "Missing 'content' (ref: https://github.com/ggerganov/llama.cpp/issues/8367)",
+    )
+  })
+
+  it('should throw an error if the content type is invalid', () => {
+    const messages = [
+      {
+        role: 'user',
+        content: 42,
+      },
+    ]
+
+    expect(() => formatChat(messages)).toThrowError(
+      "Invalid 'content' type (ref: https://github.com/ggerganov/llama.cpp/issues/8367)",
+    )
+  })
+})

src/chat.ts

@@ -0,0 +1,47 @@
+export type RNLlamaMessagePart = {
+  text?: string
+}
+
+export type RNLlamaOAICompatibleMessage = {
+  role: string
+  content?: string | RNLlamaMessagePart[] | any // any for check invalid content type
+}
+
+export type RNLlamaChatMessage = {
+  role: string
+  content: string
+}
+
+export function formatChat(
+  messages: RNLlamaOAICompatibleMessage[],
+): RNLlamaChatMessage[] {
+  const chat: RNLlamaChatMessage[] = []
+
+  messages.forEach((currMsg) => {
+    const role: string = currMsg.role || ''
+
+    let content: string = ''
+    if ('content' in currMsg) {
+      if (typeof currMsg.content === 'string') {
+        ;({ content } = currMsg)
+      } else if (Array.isArray(currMsg.content)) {
+        currMsg.content.forEach((part) => {
+          if ('text' in part) {
+            content += `${content ? '\n' : ''}${part.text}`
+          }
+        })
+      } else {
+        throw new TypeError(
+          "Invalid 'content' type (ref: https://github.com/ggerganov/llama.cpp/issues/8367)",
+        )
+      }
+    } else {
+      throw new Error(
+        "Missing 'content' (ref: https://github.com/ggerganov/llama.cpp/issues/8367)",
+      )
+    }
+
+    chat.push({ role, content })
+  })
+  return chat
+}