Bug 1509391 - [eslint] Ignore excluded files that mozlint wasn't able to handle automatically r=Standard8

Normally eslint handles its own file exclusions, but there are still some
globally excluded paths that |mach lint| passes in (e.g objdirs and things in
ThirdPartyPaths.txt).

This makes sure that if they show up in the 'config', we handle them.

Differential Revision: https://phabricator.services.mozilla.com/D12712

--HG--
extra : moz-landing-system : lando

tools/lint/eslint/__init__.py

@@ -60,6 +60,10 @@ def lint(paths, config, binary=None, fix=None, setup=None, **lintargs):
         return 1
 
     extra_args = lintargs.get('extra_args') or []
+    exclude_args = []
+    for path in config.get('exclude', []):
+        exclude_args.extend(['--ignore-pattern', os.path.relpath(path, lintargs['root'])])
+
     cmd_args = [binary,
                 os.path.join(module_path, "node_modules", "eslint", "bin", "eslint.js"),
                 # Enable the HTML plugin.
@@ -70,7 +74,7 @@ def lint(paths, config, binary=None, fix=None, setup=None, **lintargs):
                 # This keeps ext as a single argument.
                 '--ext', '[{}]'.format(','.join(config['extensions'])),
                 '--format', 'json',
-                ] + extra_args + paths
+                ] + extra_args + exclude_args + paths
 
     # eslint requires that --fix be set before the --ext argument.
     if fix:

tools/lint/test/files/eslint/subdir/bad.js

@@ -0,0 +1,2 @@
+// Missing semicolon
+let foo = "bar"

tools/lint/test/python.ini

@@ -2,4 +2,5 @@
 subsuite=mozlint, os == "linux"
 skip-if = python == 3
 
+[test_eslint.py]
 [test_flake8.py]

tools/lint/test/test_eslint.py

@@ -0,0 +1,15 @@
+import mozunit
+
+from conftest import build
+
+LINTER = 'eslint'
+
+
+def test_lint_with_global_exclude(lint, config, paths):
+    config['exclude'] = ['subdir']
+    results = lint(paths(), config=config, root=build.topsrcdir)
+    assert len(results) == 0
+
+
+if __name__ == '__main__':
+    mozunit.main()