FCM从Legacy API迁移至HTTP V1 API时TypeScript类型错误问题

我正在将FCM从Legacy API迁移到HTTP V1 API，迁移前后代码如下：

迁移前（Legacy API）代码 #

const payload = {
    data: {
        title: "Alert: New Query",
        body: "You have received a new order query",
        icon: "default"
    }
}

const options = {
    priority: "high"
}
await admin.messaging().sendToDevice(pharmToken, payload, options)

迁移后（HTTP V1 API）代码 #

const message = {
    name: 'Alert',
    notification: {
        title: 'Alert: New Query!'
    },
    data: {
        title: "Alert: New Query",
        body: "You have received a new order query",
        icon: "default"
    },
    android: {
        notification: {
            title: "Alert: New Query",
            body: "You have received a new order query",
            icon: "default"
        },
        priority: "high",
    },
    token: pharmToken,
}

await admin.messaging().send(message)

但TypeScript在await admin.messaging().send(message)的message参数处报错，错误信息：

Argument of type '{ name: string; notification: { title: string; }; data: { title: string; body: string; icon: string; }; android: { notification: { title: string; body: string; icon: string; sound: string; }; priority: string; }; token: any; }' is not assignable to parameter of type 'Message'.
Type '{ name: string; notification: { title: string; }; data: { title: string; body: string; icon: string; }; android: { notification: { title: string; body: string; icon: string; sound: string; }; priority: string; }; token: any; }' is not assignable to type 'TokenMessage'.
The types of 'android.priority' are incompatible between these types.
Type 'string' is not assignable to type '"high" | "normal" | undefined'

使用的是Firebase Admin SDK。

问题原因 #

Firebase Admin SDK的TypeScript类型定义中，android.priority的类型是字面量类型"high" | "normal" | undefined，而代码中"high"被TypeScript推断为普通string类型，导致类型不兼容。

解决方法 #

有两种方式可以修复这个类型错误：

1. 使用as const强制字面量类型推断
   将priority: "high"改为priority: "high" as const，让TypeScript识别这是固定的字面量值而非通用字符串：

const message = {
    // ...其他字段
    android: {
        notification: {
            title: "Alert: New Query",
            body: "You have received a new order query",
            icon: "default"
        },
        priority: "high" as const,
    },
    token: pharmToken,
}

2. 用SDK内置类型约束变量
   直接导入并使用TokenMessage类型定义变量，TypeScript会自动校验所有字段的类型：

import { TokenMessage } from "firebase-admin/messaging";

const message: TokenMessage = {
    name: 'Alert',
    notification: {
        title: 'Alert: New Query!'
    },
    data: {
        title: "Alert: New Query",
        body: "You have received a new order query",
        icon: "default"
    },
    android: {
        notification: {
            title: "Alert: New Query",
            body: "You have received a new order query",
            icon: "default"
        },
        priority: "high",
    },
    token: pharmToken,
}

另外注意：错误信息中提到android.notification存在sound: string字段，但迁移后代码里未定义，若为笔误请保持代码与实际逻辑一致。

内容的提问来源于stack exchange，提问作者oTwo