Use arm64 micromamba for Apple Silicon (#39)

Issue:
It is best to use native architecture for the Apple Silicon if avialable.
For soma native binaries, e.g. pytorch, it is critical to use correct architecture, due to the use of architecture specific CPU extensions in the builds

Solution:
Extend download functions for mac to match CPU architecture of VSCode
Update tests to download x64 and arm64
Add downloaded binary architecture check

.gitignore

@@ -9,3 +9,5 @@ generated-icons/
 *.vsix
 tmp
 .idea
+
+/.micromamba/

package.json

@@ -131,6 +131,7 @@
     "istanbul-lib-coverage": "^3.2.0",
     "istanbul-lib-source-maps": "^4.0.1",
     "jest": "^29.5.0",
+    "mock-os": "^1.0.0",
     "prettier": "^2.8.6",
     "rimraf": "^4.4.0",
     "ts-jest": "^29.0.5",

src/micromamba/downloadMicromamba.test.ts

@@ -1,4 +1,7 @@
 import * as path from 'path'
+import { spawnSync } from 'child_process'
+import mockos from 'mock-os'
+import { platform } from 'os'
 import sh from '../sh'
 import {
   downloadMicromambaLinux,
@@ -10,9 +13,13 @@ const tmpDir = path.join(__dirname, 'tmp', path.basename(__filename))
 
 describe('downloadMicromamba', () => {
   beforeEach(async () => {
+    mockos.restore()
     await sh.rmrf(tmpDir)
     await sh.mkdirp(tmpDir)
   })
+  afterEach(() => {
+    mockos.restore()
+  })
 
   it('win32', async () => {
     await downloadMicromambaWin(tmpDir)
@@ -26,9 +33,35 @@ describe('downloadMicromamba', () => {
     expect(actual).toEqual(['micromamba'])
   }, 10000)
 
-  it('darwin', async () => {
+  const getFileInfo = (filePath: string) => {
+    const res = spawnSync('file', [filePath], { encoding: 'utf8' })
+    expect(res.error).toBeUndefined()
+    expect(res.status).toEqual(0)
+    return res.stdout
+  }
+
+  it('darwin-x64', async () => {
+    mockos({ arch: 'x64' })
+    await downloadMicromambaMac(tmpDir)
+    const actual = await sh.ls(tmpDir)
+    expect(actual).toEqual(['micromamba'])
+
+    if (platform() == 'darwin') {
+      expect(getFileInfo(path.join(tmpDir, 'micromamba'))).toContain(
+        'Mach-O 64-bit executable x86_64',
+      )
+    }
+  }, 10000)
+
+  it('darwin-arm64', async () => {
+    mockos({ arch: 'arm64' })
     await downloadMicromambaMac(tmpDir)
     const actual = await sh.ls(tmpDir)
     expect(actual).toEqual(['micromamba'])
+    if (platform() == 'darwin') {
+      expect(getFileInfo(path.join(tmpDir, 'micromamba'))).toContain(
+        'Mach-O 64-bit executable arm64',
+      )
+    }
   }, 10000)
 })

src/micromamba/downloadMicromamba.ts

@@ -5,6 +5,7 @@ import * as tar from 'tar'
 import bz2 from 'unbzip2-stream'
 import { URL } from 'url'
 import sh from '../sh'
+import * as os from 'os'
 
 export const _downloadMicromamba = async (url: string, tar: Writable): Promise<void> => {
   try {
@@ -54,8 +55,22 @@ export const downloadMicromambaWin = async (cwd: string): Promise<void> => {
   await _downloadMicromamba(url, stream)
 }
 
+const makeMacDownloadArch = (): string => {
+  const arch = os.arch()
+  switch (arch) {
+    case 'x64':
+      return '64'
+
+    case 'arm64':
+      return arch
+
+    default:
+      throw new Error(`${arch} CPU architecture is not supported by micromamba`)
+  }
+}
+
 export const downloadMicromambaMac = async (cwd: string): Promise<void> => {
-  const url = 'https://micromamba.snakepit.net/api/micromamba/osx-64/latest'
+  const url = `https://micromamba.snakepit.net/api/micromamba/osx-${makeMacDownloadArch()}/latest`
   const stream = tar.x({ cwd, strip: 1 }, ['bin/micromamba'])
   await _downloadMicromamba(url, stream)
   await sh.chmodR('755', cwd)

tests/mock-os.d.ts

@@ -0,0 +1 @@
+declare module 'mock-os'