DevTools: Make eslint mandatory and check node.js/npm modules in presubmit

third_party/WebKit/Source/devtools/scripts/lint_javascript.py

 #!/usr/bin/env python
 #
 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import os
 import os.path as path
 import re
 import subprocess
 import sys
 
+import install_node_deps
+
 files_to_lint = None
 
 if len(sys.argv) >= 2:
     if sys.argv[1] == "--help":
         print("Usage: %s [file|dir|glob]*" % path.basename(sys.argv[0]))
         print
         print(" [file|dir|glob]*  Path or glob to run eslint on.")
         print("                   If absent, the entire frontend will be checked.")
         sys.exit(0)
 
@@ skipping 18 matching lines @@
 def to_platform_path_exact(filepath):
     if not is_cygwin:
         return filepath
     output, _ = popen(["cygpath", "-w", filepath]).communicate()
     # pylint: disable=E1103
     return output.strip().replace("\\", "\\\\")
 
 scripts_path = path.dirname(path.abspath(__file__))
 devtools_path = path.dirname(scripts_path)
 devtools_frontend_path = path.join(devtools_path, "front_end")
-
-
-# Based on http://stackoverflow.com/questions/377017/test-if-executable-exists-in-python.
-def which(program):
-    def is_exe(fpath):
-        return path.isfile(fpath) and os.access(fpath, os.X_OK)
-
-    fpath, fname = path.split(program)
-    if fpath:
-        if is_exe(program):
-            return program
-    else:
-        for part in os.environ["PATH"].split(os.pathsep):
-            part = part.strip("\"")
-            exe_file = path.join(part, program)
-            if is_exe(exe_file):
-                return exe_file
-    return None
-
+eslint_path = path.join(devtools_path, "node_modules", ".bin", "eslint")
 
 print("Linting JavaScript with eslint...\n")
 
 
 def js_lint(files_list=None):
     eslint_errors_found = False
-
-    eslint_path = which("eslint")
-    if not eslint_path:
-        print("!! NOTE: Skipping JavaScript linting because eslint is not installed.")
-        print("!!   npm install -g eslint")
-        eslint_errors_found = False  # Linting is opt-in for now, so this is a soft failure
+    if not path.isfile(eslint_path):
+        print("Failed to run eslint, run ./scripts/install_node_deps.py to install eslint")

[lushnikov, 2016/09/27 03:55:13]

wait, this doesn't install eslint any more? Should it?

[chenwilliam, 2016/09/27 17:30:57]

Running install_node_deps.py executes "npm install" which installs eslint (I
added it as a devdep in package.json). I removed the instructions to install
eslint globally to avoid versioning issues (e.g. people use eslint v2 for
another project). 

+        eslint_errors_found = True
         return eslint_errors_found
 
     if files_list is None:
         files_list = [devtools_frontend_path]
     files_list = [file_name for file_name in files_list if not file_name.endswith(".eslintrc.js")]
 
     eslintconfig_path = path.join(devtools_path, "front_end/.eslintrc.js")
     eslintignore_path = path.join(devtools_path, "front_end/.eslintignore")
     exec_command = [
+        install_node_deps.get_node_path(),
         eslint_path,
         "--config", to_platform_path_exact(eslintconfig_path),
         "--ignore-path", to_platform_path_exact(eslintignore_path),
     ] + files_list
 
     eslint_proc = popen(exec_command)
     (eslint_proc_out, _) = eslint_proc.communicate()
     if eslint_proc.returncode != 0:
         eslint_errors_found = True
     else:
         print("eslint exited successfully")
 
     print(eslint_proc_out)
     return eslint_errors_found
 
 
 errors_found = js_lint(files_to_lint)
 
 if errors_found:
     print("ERRORS DETECTED")
     sys.exit(1)
-else:
-    print("OK")