Bug 1203520 - We need a DevTools ESLint plugin containing our ruleset r=gps

python/mach_commands.py

@@ -8,6 +8,9 @@ import argparse
 import logging
 import mozpack.path as mozpath
 import os
+import platform
+import subprocess
+import sys
 import which
 
 from mozbuild.base import (
@@ -20,17 +23,46 @@ from mach.decorators import (
     Command,
 )
 
-
 ESLINT_NOT_FOUND_MESSAGE = '''
 Could not find eslint!  We looked at the --binary option, at the ESLINT
 environment variable, and then at your path.  Install eslint and needed plugins
 with
 
-npm install -g eslint eslint-plugin-react
+mach eslint --setup
 
 and try again.
 '''.strip()
 
+NODE_NOT_FOUND_MESSAGE = '''
+nodejs is either not installed or is installed to a non-standard path.
+Please install nodejs from https://nodejs.org and try again.
+
+Valid installation paths:
+'''.strip()
+
+NPM_NOT_FOUND_MESSAGE = '''
+Node Package Manager (npm) is either not installed or installed to a
+non-standard path. Please install npm from https://nodejs.org (it comes as an
+option in the node installation) and try again.
+
+Valid installation paths:
+'''.strip()
+
+ESLINT_PROMPT = '''
+Would you like to use eslint
+'''.strip()
+
+ESLINT_PLUGIN_MOZILLA_PROMPT = '''
+eslint-plugin-mozilla is an eslint plugin containing rules that help enforce
+JavaScript coding standards in the Mozilla project. Would you like to use this
+plugin
+'''.strip()
+
+ESLINT_PLUGIN_REACT_PROMPT = '''
+eslint-plugin-react is an eslint plugin containing rules that help React
+developers follow strict guidelines. Would you like to install it
+'''.strip()
+
 
 @CommandProvider
 class MachCommands(MachCommandBase):
@@ -132,7 +164,10 @@ class MachCommands(MachCommandBase):
 
         return 0 if return_code == 0 else 1
 
-    @Command('eslint', category='devenv')
+    @Command('eslint', category='devenv',
+        description='Run eslint or help configure eslint for optimal development.')
+    @CommandArgument('-s', '--setup', default=False, action='store_true',
+        help='configure eslint for optimal development.')
     @CommandArgument('path', nargs='?', default='.',
         help='Path to files to lint, like "browser/components/loop" '
             'or "mobile/android". '
@@ -142,9 +177,12 @@ class MachCommands(MachCommandBase):
     @CommandArgument('-b', '--binary', default=None,
         help='Path to eslint binary.')
     @CommandArgument('args', nargs=argparse.REMAINDER)  # Passed through to eslint.
-    def eslint(self, path, ext=None, binary=None, args=[]):
+    def eslint(self, setup, path, ext=None, binary=None, args=[]):
         '''Run eslint.'''
 
+        if setup:
+            return self.eslint_setup()
+
         if not binary:
             binary = os.environ.get('ESLINT', None)
             if not binary:
@@ -182,3 +220,100 @@ class MachCommands(MachCommandBase):
             pass_thru=True,  # Allow user to run eslint interactively.
             ensure_exit_code=False,  # Don't throw on non-zero exit code.
         )
+    def eslint_setup(self, update_only=False):
+        """Ensure eslint is optimally configured.
+
+        This command will inspect your eslint configuration and
+        guide you through an interactive wizard helping you configure
+        eslint for optimal use on Mozilla projects.
+        """
+        sys.path.append(os.path.dirname(__file__))
+
+        # At the very least we need node installed.
+        nodePath = self.getNodeOrNpmPath("node")
+        if not nodePath:
+            return 1
+
+        npmPath = self.getNodeOrNpmPath("npm")
+        if not npmPath:
+            return 1
+
+        # Install eslint.
+        print("Installing eslint...")
+        with open(os.devnull, "w") as fnull:
+            subprocess.call([npmPath, "install", "eslint", "-g"],
+                            stdout=fnull, stderr=fnull)
+
+        # Install eslint-plugin-mozilla.
+        print("")
+        print("Installing eslint-plugin-mozilla...")
+        with open(os.devnull, "w") as fnull:
+            subprocess.call([npmPath, "link"],
+                            cwd="testing/eslint-plugin-mozilla",
+                            stdout=fnull, stderr=fnull)
+
+        # Install eslint-plugin-react.
+        print("")
+        print("Installing eslint-plugin-react...")
+        with open(os.devnull, "w") as fnull:
+            subprocess.call([npmPath, "install", "-g", "eslint-plugin-react"],
+                            stdout=fnull, stderr=fnull)
+
+    def getPossibleNodePathsWin(self):
+        """
+        Return possible nodejs paths on Windows.
+        """
+        if platform.system() != "Windows":
+            return []
+
+        return {
+            "%s\\nodejs" % os.environ.get("SystemDrive"),
+            os.path.join(os.environ.get("ProgramFiles"), "nodejs"),
+            os.path.join(os.environ.get("PROGRAMW6432"), "nodejs"),
+            os.path.join(os.environ.get("PROGRAMFILES"), "nodejs")
+        }
+
+    def getNodeOrNpmPath(self, filename):
+        """
+        Return the nodejs or npm path.
+        """
+        try:
+            appPath = which.which(filename)
+            return appPath
+        except which.WhichError:
+            pass
+
+        if platform.system() == "Windows":
+            try:
+                for ext in ["", ".cmd", ".exe"]:
+                    nodeOrNpmPath = which.which(filename + ext,
+                                                path=self.getPossibleNodePathsWin())
+                    if self.is_valid(nodeOrNpmPath):
+                        return nodeOrNpmPath
+            except which.WhichError:
+                pass
+
+        if filename == "node":
+            print(NODE_NOT_FOUND_MESSAGE)
+        elif filename == "npm":
+            print(NPM_NOT_FOUND_MESSAGE)
+
+        if platform.system() == "Windows":
+            appPaths = self.getPossibleNodePathsWin()
+
+            for p in appPaths:
+                print("  - " + p)
+        elif platform.system() == "Darwin":
+            print("  - /usr/local/bin/node")
+        elif platform.system() == "Linux":
+            print("  - /usr/bin/nodejs")
+
+        return None
+
+    def is_valid(self, path):
+        try:
+            with open(os.devnull, "w") as fnull:
+                subprocess.check_call([path, "--version"], stdout=fnull)
+                return True
+        except subprocess.CalledProcessError:
+            return False