[python] Add support for pip3.10 and pip3.11 in vc build (#10648)

packages/python/package.json

@@ -22,10 +22,14 @@
   },
   "devDependencies": {
     "@types/execa": "^0.9.0",
+    "@types/fs-extra": "11.0.2",
     "@types/jest": "27.4.1",
     "@types/node": "14.18.33",
+    "@types/which": "3.0.0",
     "@vercel/build-utils": "7.2.2",
     "execa": "^1.0.0",
-    "jest-junit": "16.0.0"
+    "fs-extra": "11.1.1",
+    "jest-junit": "16.0.0",
+    "which": "3.0.0"
   }
 }

packages/python/src/version.ts

@@ -1,4 +1,5 @@
 import { NowBuildError } from '@vercel/build-utils';
+import which from 'which';
 
 interface PythonVersion {
   version: string;
@@ -10,6 +11,18 @@ interface PythonVersion {
 
 // The order must be most recent first
 const allOptions: PythonVersion[] = [
+  {
+    version: '3.11',
+    pipPath: 'pip3.11',
+    pythonPath: 'python3.11',
+    runtime: 'python3.11',
+  },
+  {
+    version: '3.10',
+    pipPath: 'pip3.10',
+    pythonPath: 'python3.10',
+    runtime: 'python3.10',
+  },
   {
     version: '3.9',
     pipPath: 'pip3.9',
@@ -34,6 +47,7 @@ function getDevPythonVersion(): PythonVersion {
     runtime: 'python3',
   };
 }
+
 export function getLatestPythonVersion({
   isDev,
 }: {
@@ -42,7 +56,16 @@ export function getLatestPythonVersion({
   if (isDev) {
     return getDevPythonVersion();
   }
-  return allOptions[0];
+
+  const selection = allOptions.find(isInstalled);
+  if (!selection) {
+    throw new NowBuildError({
+      code: 'PYTHON_NOT_FOUND',
+      link: 'http://vercel.link/python-version',
+      message: `Unable to find any supported Python versions.`,
+    });
+  }
+  return selection;
 }
 
 export function getSupportedPythonVersion({
@@ -55,10 +78,13 @@ export function getSupportedPythonVersion({
   if (isDev) {
     return getDevPythonVersion();
   }
+
   let selection = getLatestPythonVersion({ isDev: false });
 
   if (typeof pipLockPythonVersion === 'string') {
-    const found = allOptions.find(o => o.version === pipLockPythonVersion);
+    const found = allOptions.find(
+      o => o.version === pipLockPythonVersion && isInstalled(o)
+    );
     if (found) {
       selection = found;
     } else {
@@ -90,3 +116,10 @@ function isDiscontinued({ discontinueDate }: PythonVersion): boolean {
   const today = Date.now();
   return discontinueDate !== undefined && discontinueDate.getTime() <= today;
 }
+
+function isInstalled({ pipPath, pythonPath }: PythonVersion): boolean {
+  return (
+    Boolean(which.sync(pipPath, { nothrow: true })) &&
+    Boolean(which.sync(pythonPath, { nothrow: true }))
+  );
+}

packages/python/test/unit.test.ts

@@ -1,8 +1,17 @@
 import { getSupportedPythonVersion } from '../src/version';
+import fs from 'fs-extra';
+import path from 'path';
+import { tmpdir } from 'os';
 
+const tmpPythonDir = path.join(
+  tmpdir(),
+  `vc-test-python-${Math.floor(Math.random() * 1e6)}`
+);
 let warningMessages: string[];
 const originalConsoleWarn = console.warn;
 const realDateNow = Date.now.bind(global.Date);
+const origPath = process.env.PATH;
+
 beforeEach(() => {
   warningMessages = [];
   console.warn = m => {
@@ -13,15 +22,19 @@ beforeEach(() => {
 afterEach(() => {
   console.warn = originalConsoleWarn;
   global.Date.now = realDateNow;
+  process.env.PATH = origPath;
+  if (fs.existsSync(tmpPythonDir)) {
+    fs.removeSync(tmpPythonDir);
+  }
 });
 
-it('should only match supported versions, otherwise throw an error', async () => {
-  expect(
-    getSupportedPythonVersion({ pipLockPythonVersion: '3.9' })
-  ).toHaveProperty('runtime', 'python3.9');
+it('should only match supported versions, otherwise throw an error', () => {
+  makeMockPython('3.9');
+  const result = getSupportedPythonVersion({ pipLockPythonVersion: '3.9' });
+  expect(result).toHaveProperty('runtime', 'python3.9');
 });
 
-it('should ignore minor version in vercel dev', async () => {
+it('should ignore minor version in vercel dev', () => {
   expect(
     getSupportedPythonVersion({ pipLockPythonVersion: '3.9', isDev: true })
   ).toHaveProperty('runtime', 'python3');
@@ -34,24 +47,34 @@ it('should ignore minor version in vercel dev', async () => {
   expect(warningMessages).toStrictEqual([]);
 });
 
-it('should select latest version when no Piplock detected', async () => {
-  expect(
-    getSupportedPythonVersion({ pipLockPythonVersion: undefined })
-  ).toHaveProperty('runtime', 'python3.9');
+it('should select latest supported installed version when no Piplock detected', () => {
+  const result = getSupportedPythonVersion({ pipLockPythonVersion: undefined });
+  expect(result).toHaveProperty('runtime');
+  expect(result.runtime).toMatch(/^python3\.\d+$/);
   expect(warningMessages).toStrictEqual([]);
 });
 
-it('should select latest version and warn when invalid Piplock detected', async () => {
-  expect(
-    getSupportedPythonVersion({ pipLockPythonVersion: '999' })
-  ).toHaveProperty('runtime', 'python3.9');
+it('should select latest supported installed version and warn when invalid Piplock detected', () => {
+  const result = getSupportedPythonVersion({ pipLockPythonVersion: '999' });
+  expect(result).toHaveProperty('runtime');
+  expect(result.runtime).toMatch(/^python3\.\d+$/);
   expect(warningMessages).toStrictEqual([
     'Warning: Python version "999" detected in Pipfile.lock is invalid and will be ignored. http://vercel.link/python-version',
   ]);
 });
 
-it('should throw for discontinued versions', async () => {
+it('should throw if python not found', () => {
+  process.env.PATH = '.';
+  expect(() =>
+    getSupportedPythonVersion({ pipLockPythonVersion: '3.6' })
+  ).toThrow('Unable to find any supported Python versions.');
+  expect(warningMessages).toStrictEqual([]);
+});
+
+it('should throw for discontinued versions', () => {
   global.Date.now = () => new Date('2022-07-31').getTime();
+  makeMockPython('3.6');
+
   expect(() =>
     getSupportedPythonVersion({ pipLockPythonVersion: '3.6' })
   ).toThrow(
@@ -60,8 +83,9 @@ it('should throw for discontinued versions', async () => {
   expect(warningMessages).toStrictEqual([]);
 });
 
-it('should warn for deprecated versions, soon to be discontinued', async () => {
+it('should warn for deprecated versions, soon to be discontinued', () => {
   global.Date.now = () => new Date('2021-07-01').getTime();
+  makeMockPython('3.6');
 
   expect(
     getSupportedPythonVersion({ pipLockPythonVersion: '3.6' })
@@ -70,3 +94,16 @@ it('should warn for deprecated versions, soon to be discontinued', async () => {
     'Error: Python version "3.6" detected in Pipfile.lock has reached End-of-Life. Deployments created on or after 2022-07-18 will fail to build. http://vercel.link/python-version',
   ]);
 });
+
+function makeMockPython(version: string) {
+  fs.mkdirSync(tmpPythonDir);
+  for (const name of ['python', 'pip']) {
+    const bin = path.join(
+      tmpPythonDir,
+      `${name}${version}${process.platform === 'win32' ? '.exe' : ''}`
+    );
+    fs.writeFileSync(bin, '');
+    fs.chmodSync(bin, 0o755);
+  }
+  process.env.PATH = `${tmpPythonDir}${path.delimiter}${process.env.PATH}`;
+}