python: move Python detection to its own file

PR-URL: #1815
Reviewed-By: Christian Clauss <[email protected]>
Reviewed-By: Richard Lau <[email protected]>

Author: joaocgreis

lib/configure.js

@@ -4,15 +4,12 @@ const fs = require('graceful-fs')
 const path = require('path')
 const log = require('npmlog')
 const os = require('os')
-const semver = require('semver')
 const mkdirp = require('mkdirp')
-const cp = require('child_process')
-const extend = require('util')._extend // eslint-disable-line
 const processRelease = require('./process-release')
 const win = process.platform === 'win32'
 const findNodeDirectory = require('./find-node-directory')
 const msgFormat = require('util').format
-const logWithPrefix = require('./util').logWithPrefix
+var findPython = require('./find-python')
 if (win) {
   var findVisualStudio = require('./find-visualstudio')
 }
@@ -375,287 +372,8 @@ function findAccessibleSync (logprefix, dir, candidates) {
   return undefined
 }
 
-function PythonFinder (configPython, callback) {
-  this.callback = callback
-  this.configPython = configPython
-  this.errorLog = []
-}
-
-PythonFinder.prototype = {
-  log: logWithPrefix(log, 'find Python'),
-  argsExecutable: [ '-c', 'import sys; print(sys.executable);' ],
-  argsVersion: [ '-c', 'import sys; print("%s.%s.%s" % sys.version_info[:3]);' ],
-  semverRange: '>=2.6.0 <3.0.0',
-
-  // These can be overridden for testing:
-  execFile: cp.execFile,
-  env: process.env,
-  win: win,
-  pyLauncher: 'py.exe',
-  defaultLocation: path.join(process.env.SystemDrive || 'C:', 'Python27',
-    'python.exe'),
-
-  // Logs a message at verbose level, but also saves it to be displayed later
-  // at error level if an error occurs. This should help diagnose the problem.
-  addLog: function addLog (message) {
-    this.log.verbose(message)
-    this.errorLog.push(message)
-  },
-
-  // Find Python by trying a sequence of possibilities.
-  // Ignore errors, keep trying until Python is found.
-  findPython: function findPython () {
-    const SKIP = 0; const FAIL = 1
-    const toCheck = [
-      {
-        before: () => {
-          if (!this.configPython) {
-            this.addLog(
-              'Python is not set from command line or npm configuration')
-            return SKIP
-          }
-          this.addLog('checking Python explicitly set from command line or ' +
-            'npm configuration')
-          this.addLog('- "--python=" or "npm config get python" is ' +
-            `"${this.configPython}"`)
-        },
-        check: this.checkCommand,
-        arg: this.configPython
-      },
-      {
-        before: () => {
-          if (!this.env.PYTHON) {
-            this.addLog('Python is not set from environment variable PYTHON')
-            return SKIP
-          }
-          this.addLog(
-            'checking Python explicitly set from environment variable PYTHON')
-          this.addLog(`- process.env.PYTHON is "${this.env.PYTHON}"`)
-        },
-        check: this.checkCommand,
-        arg: this.env.PYTHON
-      },
-      {
-        before: () => { this.addLog('checking if "python2" can be used') },
-        check: this.checkCommand,
-        arg: 'python2'
-      },
-      {
-        before: () => { this.addLog('checking if "python" can be used') },
-        check: this.checkCommand,
-        arg: 'python'
-      },
-      {
-        before: () => {
-          if (!this.win) {
-            // Everything after this is Windows specific
-            return FAIL
-          }
-          this.addLog(
-            'checking if the py launcher can be used to find Python 2')
-        },
-        check: this.checkPyLauncher
-      },
-      {
-        before: () => {
-          this.addLog(
-            'checking if Python 2 is installed in the default location')
-        },
-        check: this.checkExecPath,
-        arg: this.defaultLocation
-      }
-    ]
-
-    function runChecks (err) {
-      this.log.silly('runChecks: err = %j', (err && err.stack) || err)
-
-      const check = toCheck.shift()
-      if (!check) {
-        return this.fail()
-      }
-
-      const before = check.before.apply(this)
-      if (before === SKIP) {
-        return runChecks.apply(this)
-      }
-      if (before === FAIL) {
-        return this.fail()
-      }
-
-      const args = [ runChecks.bind(this) ]
-      if (check.arg) {
-        args.unshift(check.arg)
-      }
-      check.check.apply(this, args)
-    }
-
-    runChecks.apply(this)
-  },
-
-  // Check if command is a valid Python to use.
-  // Will exit the Python finder on success.
-  // If on Windows, run in a CMD shell to support BAT/CMD launchers.
-  checkCommand: function checkCommand (command, errorCallback) {
-    var exec = command
-    var args = this.argsExecutable
-    var shell = false
-    if (this.win) {
-      // Arguments have to be manually quoted
-      exec = `"${exec}"`
-      args = args.map(a => `"${a}"`)
-      shell = true
-    }
-
-    this.log.verbose(`- executing "${command}" to get executable path`)
-    this.run(exec, args, shell, function (err, execPath) {
-      // Possible outcomes:
-      // - Error: not in PATH, not executable or execution fails
-      // - Gibberish: the next command to check version will fail
-      // - Absolute path to executable
-      if (err) {
-        this.addLog(`- "${command}" is not in PATH or produced an error`)
-        return errorCallback(err)
-      }
-      this.addLog(`- executable path is "${execPath}"`)
-      this.checkExecPath(execPath, errorCallback)
-    }.bind(this))
-  },
-
-  // Check if the py launcher can find a valid Python to use.
-  // Will exit the Python finder on success.
-  // Distributions of Python on Windows by default install with the "py.exe"
-  // Python launcher which is more likely to exist than the Python executable
-  // being in the $PATH.
-  // Because the Python launcher supports all versions of Python, we have to
-  // explicitly request a Python 2 version. This is done by supplying "-2" as
-  // the first command line argument. Since "py.exe -2" would be an invalid
-  // executable for "execFile", we have to use the launcher to figure out
-  // where the actual "python.exe" executable is located.
-  checkPyLauncher: function checkPyLauncher (errorCallback) {
-    this.log.verbose(
-      `- executing "${this.pyLauncher}" to get Python 2 executable path`)
-    this.run(this.pyLauncher, [ '-2', ...this.argsExecutable ], false,
-      function (err, execPath) {
-      // Possible outcomes: same as checkCommand
-        if (err) {
-          this.addLog(
-            `- "${this.pyLauncher}" is not in PATH or produced an error`)
-          return errorCallback(err)
-        }
-        this.addLog(`- executable path is "${execPath}"`)
-        this.checkExecPath(execPath, errorCallback)
-      }.bind(this))
-  },
-
-  // Check if a Python executable is the correct version to use.
-  // Will exit the Python finder on success.
-  checkExecPath: function checkExecPath (execPath, errorCallback) {
-    this.log.verbose(`- executing "${execPath}" to get version`)
-    this.run(execPath, this.argsVersion, false, function (err, version) {
-      // Possible outcomes:
-      // - Error: executable can not be run (likely meaning the command wasn't
-      //   a Python executable and the previous command produced gibberish)
-      // - Gibberish: somehow the last command produced an executable path,
-      //   this will fail when verifying the version
-      // - Version of the Python executable
-      if (err) {
-        this.addLog(`- "${execPath}" could not be run`)
-        return errorCallback(err)
-      }
-      this.addLog(`- version is "${version}"`)
-
-      const range = semver.Range(this.semverRange)
-      var valid = false
-      try {
-        valid = range.test(version)
-      } catch (err) {
-        this.log.silly('range.test() threw:\n%s', err.stack)
-        this.addLog(`- "${execPath}" does not have a valid version`)
-        this.addLog('- is it a Python executable?')
-        return errorCallback(err)
-      }
-
-      if (!valid) {
-        this.addLog(`- version is ${version} - should be ${this.semverRange}`)
-        this.addLog('- THIS VERSION OF PYTHON IS NOT SUPPORTED')
-        return errorCallback(new Error(
-          `Found unsupported Python version ${version}`))
-      }
-      this.succeed(execPath, version)
-    }.bind(this))
-  },
-
-  // Run an executable or shell command, trimming the output.
-  run: function run (exec, args, shell, callback) {
-    var env = extend({}, this.env)
-    env.TERM = 'dumb'
-    const opts = { env: env, shell: shell }
-
-    this.log.silly('execFile: exec = %j', exec)
-    this.log.silly('execFile: args = %j', args)
-    this.log.silly('execFile: opts = %j', opts)
-    try {
-      this.execFile(exec, args, opts, execFileCallback.bind(this))
-    } catch (err) {
-      this.log.silly('execFile: threw:\n%s', err.stack)
-      return callback(err)
-    }
-
-    function execFileCallback (err, stdout, stderr) {
-      this.log.silly('execFile result: err = %j', (err && err.stack) || err)
-      this.log.silly('execFile result: stdout = %j', stdout)
-      this.log.silly('execFile result: stderr = %j', stderr)
-      if (err) {
-        return callback(err)
-      }
-      const execPath = stdout.trim()
-      callback(null, execPath)
-    }
-  },
-
-  succeed: function succeed (execPath, version) {
-    this.log.info(`using Python version ${version} found at "${execPath}"`)
-    process.nextTick(this.callback.bind(null, null, execPath))
-  },
-
-  fail: function fail () {
-    const errorLog = this.errorLog.join('\n')
-
-    const pathExample = this.win ? 'C:\\Path\\To\\python.exe'
-      : '/path/to/pythonexecutable'
-    // For Windows 80 col console, use up to the column before the one marked
-    // with X (total 79 chars including logger prefix, 58 chars usable here):
-    //                                                           X
-    const info = [
-      '**********************************************************',
-      'You need to install the latest version of Python 2.7.',
-      'Node-gyp should be able to find and use Python. If not,',
-      'you can try one of the following options:',
-      `- Use the switch --python="${pathExample}"`,
-      '  (accepted by both node-gyp and npm)',
-      '- Set the environment variable PYTHON',
-      '- Set the npm configuration variable python:',
-      `  npm config set python "${pathExample}"`,
-      'For more information consult the documentation at:',
-      'https://github.com/nodejs/node-gyp#installation',
-      '**********************************************************'
-    ].join('\n')
-
-    this.log.error(`\n${errorLog}\n\n${info}\n`)
-    process.nextTick(this.callback.bind(null, new Error(
-      'Could not find any Python 2 installation to use')))
-  }
-}
-
-function findPython (configPython, callback) {
-  var finder = new PythonFinder(configPython, callback)
-  finder.findPython()
-}
-
 module.exports = configure
 module.exports.test = {
-  PythonFinder: PythonFinder,
-  findAccessibleSync: findAccessibleSync,
-  findPython: findPython
+  findAccessibleSync: findAccessibleSync
 }
 module.exports.usage = 'Generates ' + (win ? 'MSVC project files' : 'a Makefile') + ' for the current module'