Bug 1230776: Support scripts from HTML files in eslint. r=gps

Also removes related unused variables in mach_commands.py.

.eslintignore

@@ -4,6 +4,10 @@
 # Exclude expected objdirs.
 obj*/**
 
+# Temporarily ignore HTML files that still need to be fixed.
+browser/extensions/loop/**/*.html
+devtools/**/*.html
+
 # We ignore all these directories by default, until we get them enabled.
 # If you are enabling a directory, please add directory specific exclusions
 # below.

python/mach_commands.py

@@ -48,21 +48,6 @@
 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):
@@ -168,8 +153,8 @@ def _line_handler(line):
         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('-e', '--ext', default='[.js,.jsm,.jsx,.xml]',
-        help='Filename extensions to lint, default: "[.js,.jsm,.jsx]".')
+    @CommandArgument('-e', '--ext', default='[.js,.jsm,.jsx,.xml,.html]',
+        help='Filename extensions to lint, default: "[.js,.jsm,.jsx,.xml,.html]".')
     @CommandArgument('-b', '--binary', default=None,
         help='Path to eslint binary.')
     @CommandArgument('args', nargs=argparse.REMAINDER)  # Passed through to eslint.
@@ -197,8 +182,13 @@ def eslint(self, setup, ext=None, binary=None, args=None):
         args = args or ['.']
 
         cmd_args = [binary,
-            '--ext', ext,  # This keeps ext as a single argument.
-        ] + args
+                    # Enable the HTML plugin.
+                    # We can't currently enable this in the global config file
+                    # because it has bad interactions with the SublimeText
+                    # ESLint plugin (bug 1229874).
+                    '--plugin', 'html',
+                    '--ext', ext,  # This keeps ext as a single argument.
+                    ] + args
 
         success = self.run_process(cmd_args,
             pass_thru=True,  # Allow user to run eslint interactively.
@@ -241,6 +231,12 @@ def eslint_setup(self, update_only=False):
         if not success:
             return 1
 
+        # Install eslint-plugin-html.
+        success = self.callProcess("eslint-plugin-html",
+                                   [npmPath, "install", "eslint-plugin-html", "-g"])
+        if not success:
+            return 1
+
         # Install eslint-plugin-react.
         success = self.callProcess("eslint-plugin-react",
                                    [npmPath, "install", "eslint-plugin-react", "-g"])