Closure compilation: Modify compile_js2.py to not swallow errors.

third_party/closure_compiler/compile2.py

Index: third_party/closure_compiler/compile2.py
diff --git a/third_party/closure_compiler/compile2.py b/third_party/closure_compiler/compile2.py
index 224856d7227192fd022b0f655d4574c414254349..8b4f26405983d35d5d516e2781979c565a1ec90a 100755
--- a/third_party/closure_compiler/compile2.py
+++ b/third_party/closure_compiler/compile2.py
@@ -176,8 +176,12 @@ class Checker(object):
           in GYP dependency order).
 
     Returns:
-      (found_errors, stderr) A boolean indicating whether errors were found and
-          the raw Closure compiler stderr (as a string).
+      (return_code, found_errors, stderr) The return code from the jar command,
+          a boolean indicating whether type checking related errors were found
+          and the raw Closure compiler stderr (as a string). Note that it is
+          possible for |found_errors| to be false, and |return_code| to be
+          non-zero, for example when wrong flags are passed to the compiler
+          (which yields an InvalidOptionsException)
     """
     is_extern = lambda f: 'externs' in f
     externs_and_deps = [self._POLYMER_EXTERNS]
@@ -243,7 +247,7 @@ class Checker(object):
 
     self._log_debug("Args: %s" % " ".join(args))
 
-    _, stderr = self.run_jar(self._compiler_jar, args)
+    return_code, stderr = self.run_jar(self._compiler_jar, args)
 
     errors = stderr.strip().split("\n\n")
     maybe_summary = errors.pop()
@@ -280,7 +284,7 @@ class Checker(object):
         self._log_debug("Output: %s" % output)
 
     self._nuke_temp_files()
-    return bool(errors), stderr
+    return return_code, bool(errors), stderr

[dpapad, 2017/06/08 22:26:05]

An alternative to adding a new return variable, is to do something like

return bool(errors) or return_code > 0, stderr

Let me know if you think that's better (simpler, cleaner etc).

 
 
 if __name__ == "__main__":
@@ -303,12 +307,13 @@ if __name__ == "__main__":
 
   checker = Checker(verbose=opts.verbose)
 
-  found_errors, stderr = checker.check(opts.sources, out_file=opts.out_file,
-                                       closure_args=opts.closure_args,
-                                       custom_sources=opts.custom_sources,
-                                       custom_includes=opts.custom_includes)
+  return_code, found_errors, stderr = checker.check(
+      opts.sources, out_file=opts.out_file,
+      closure_args=opts.closure_args,
+      custom_sources=opts.custom_sources,
+      custom_includes=opts.custom_includes)
 
-  if found_errors:
+  if found_errors or return_code > 0 :
     if opts.custom_sources:
       print stderr
     sys.exit(1)