install-dmg.ts

// Name: Install app from dmg in Downloads

/// Implementation notes:
/// - dmg file name can be different from mounted volume name, e.g. UIBrowser302.dmg -> /Volumes/UI Browser 3.0.2.0
/// - dmg might contain License agreement that needs to be accepted, e.g. UIBrowser302.dmg
/// - dmg might contain other files than just the app, e.g. Extras folder and README.rtf, see UIBrowser302.dmg

import "@johnlindquist/kit"
import fs, {statSync, unlinkSync} from "fs";
import {join} from "path";
import * as luxon from "luxon"
import {execa} from "execa";
import {execSync} from "child_process"

let downloadsDir = home("Downloads") // Feel free to change

let dmgPaths = await globby("*.dmg", { cwd: downloadsDir })

let dmgObjs = dmgPaths.map(path => ({
    fullPath: join(downloadsDir, path), 
    baseName: path.split("/").pop()?.replace(".dmg", ""),
    createdAt: statSync(join(downloadsDir, path)).ctime.getTime(),
    sizeInMb: statSync(join(downloadsDir, path)).size / 1024 / 1024
})).sort((a, b) => b.createdAt - a.createdAt)

if (dmgObjs.length === 0) {
    setPlaceholder("No DMG files found in Downloads directory")
} else {
    let selectedDmgPath = await arg({
        placeholder: "Which dmg?", 
        choices: dmgObjs.map(dmg => ({
            value: dmg.fullPath,
            name: dmg.baseName,
            description: `${luxon.DateTime.fromMillis(dmg.createdAt).toFormat('yyyy-MM-dd HH:mm')} • ${dmg.sizeInMb.toFixed(2)} MB`
        }))
    })
    
    console.log(`Mounting ${selectedDmgPath}`)
    let volumeName = await attachDmg(selectedDmgPath)
    let mountPath = `/Volumes/${volumeName}`;
    console.log(`Mounted to ${mountPath}`)
    // Note: Globby did not work for me for mounted volumes
    let apps = fs.readdirSync(mountPath).filter(f => f.endsWith(".app"))

    if (apps.length === 0) {
        setPlaceholder("No apps found in the mounted volume")
        // TODO: Find a better way to do early returns/exits
    } else {
        let confirmed = await arg({
            placeholder: `Found ${apps.length} apps: ${apps.join(", ")}, install?`,
            choices: ["yes", "no"]
        })
        
        if (confirmed !== "yes") {
            notify("Aborted")
            process.exit(0)
        }
        
        for (let app of apps) {
          console.log(`Copying ${app} to /Applications folder`);
          await execa(`cp`, [
            '-a', `${mountPath}/${app}`,
            '/Applications/'
          ]);
        }
        
        console.log(`Detaching ${mountPath}`)
        await detachDmg(mountPath)
        
        let confirmDeletion = await arg({
            placeholder: `Delete ${selectedDmgPath}?`,
            choices: ["yes", "no"]
        })
        
        if (confirmDeletion === "yes") {
            console.log(`Deleting ${selectedDmgPath}`)
            await trash(selectedDmgPath)
        }
    }
}


// Helpers
// ===
async function attachDmg(dmgPath: string): Promise<string> {
    // https://superuser.com/questions/221136/bypass-a-licence-agreement-when-mounting-a-dmg-on-the-command-line
    let out = execSync(`yes | PAGER=cat hdiutil attach "${dmgPath}"`).toString()
    let lines = out.split("\n").reverse()
    // from the end, find line with volume name
    // /dev/disk6s2 Apple_HFS /Volumes/UI Browser 3.0.2.0
    let lineWithVolume = lines.find(line => line.includes("/Volumes/"))
    if (!lineWithVolume) {
        throw new Error(`Failed to find volume name in output: ${out}`)
    }
    let volumeName = lineWithVolume.split(`/Volumes/`)[1]
    return volumeName
}

async function detachDmg(mountPoint: string) {
    await execa('hdiutil', ['detach', mountPoint])
}