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prescience-data/download-chrome.ts

Created December 8, 2021 00:20
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  1. prescience-data created this gist Dec 8, 2021.
    103 changes: 103 additions & 0 deletions download-chrome.ts
    View file
    Original file line number Diff line number Diff line change
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    import { createWriteStream, ensureDir } from "fs-extra"
    import got from "got"
    import { Stream } from "stream"

    export type Platform =
    | "Win_x64"
    | "Win"
    | "Mac"
    | "Mac_Arm"
    | "Linux_x64"
    | "Android" // etc

    export interface BuildParams {
    platform: Platform
    }

    export interface SnapshotParams {
    platform: Platform
    build: string | number
    filename: string
    }

    export interface DownloadParams {
    dest: string
    platform: Platform
    build?: string | number
    }

    /**
    * Define the base Google storage url.
    * @type {string}
    */
    const BASE_URL: string = `https://www.googleapis.com/download/storage/v1/b/chromium-browser-snapshots/o`

    /**
    * Prepares a valid snapshot filename from platform.
    *
    * @param {Platform} platform
    * @return {string}
    */
    const getSnapshotFilename = (platform: Platform): string =>
    `chrome-${platform.split(`_`)[0].toLowerCase()}.zip`

    /**
    * Returns the most current build version for a specific platform.
    *
    * @param {"Win_x64" | "Win" | "Mac" | "Mac_Arm" | "Linux_x64" | "Android"} platform
    * @return {Promise<string>}
    */
    export const fetchBuild = async ({ platform }: BuildParams): Promise<string> =>
    got(`${BASE_URL}/${platform}%2FLAST_CHANGE?generation=0&alt=media`).text()

    /**
    * Begins streaming the snapshot archive file.
    *
    * @param {"Win_x64" | "Win" | "Mac" | "Mac_Arm" | "Linux_x64" | "Android"} platform
    * @param {string | number} build
    * @param {string} filename
    * @return {Stream}
    */
    export const fetchSnapshot = ({
    platform,
    build,
    filename
    }: SnapshotParams): Stream =>
    got.stream(
    `${BASE_URL}/${platform}%2F${build}%2F${filename}?generation=0&alt=media`
    )

    /**
    * Primary entrypoint to begin a browser download.
    * Must define a target destination and platform.
    * Browser build version can optionally be provided, or falls back to most current.
    * Returns the path to the downloaded file, or rejects with an error.
    *
    * @param {string} dest
    * @param {"Win_x64" | "Win" | "Mac" | "Mac_Arm" | "Linux_x64" | "Android"} platform
    * @param {string | number | undefined} build
    * @return {Promise<string>}
    */
    export const downloadBrowser = async ({
    dest,
    platform,
    build
    }: DownloadParams): Promise<string> => {
    const params: SnapshotParams = {
    platform,
    build: build ?? (await fetchBuild({ platform })),
    filename: getSnapshotFilename(platform)
    }
    const pathToSnapshot: string = `${dest}/${params.filename}`
    await ensureDir(dest)
    await new Promise((resolve, reject) => {
    fetchSnapshot(params)
    .on("error", reject)
    .pipe(
    createWriteStream(pathToSnapshot)
    .on("error", reject)
    .on("finish", resolve)
    )
    })
    return pathToSnapshot
    }