Refactor the license check to be a generic presubmit check (#131)

* Refactor the license check to be a generic presubmit check

This includes all of the old presubmits that were in our METADATA file
that are still valid.

* Responses to CR

Added docstrings, refactored the file finder, changed variable names,
and formatted the file

* More respones to CR

config/presubmits.py

@@ -0,0 +1,180 @@
+# Copyright 2019 The Nomulus Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Google-style presubmits for the Nomulus project.
+
+These aren't built in to the static code analysis tools we use (e.g. Checkstyle,
+Error Prone) so we must write them manually.
+"""
+
+import os
+import sys
+import re
+
+# We should never analyze any generated files
+UNIVERSALLY_SKIPPED_PATTERNS = {"/build/", "/out/"}
+# We can't rely on CI to have the Enum package installed so we do this instead.
+FORBIDDEN = 1
+REQUIRED = 2
+
+
+class PresubmitCheck:
+
+  def __init__(self,
+               regex,
+               included_extensions,
+               skipped_patterns,
+               regex_type=FORBIDDEN):
+    """Define a presubmit check for a particular set of files,
+
+        The provided prefix should always or never be included in the files.
+
+        Args:
+            regex: the regular expression to forbid or require
+            included_extensions: a tuple of extensions that define which files
+              we run over
+            skipped_patterns: a set of patterns that will cause any files that
+              include them to be skipped
+            regex_type: either FORBIDDEN or REQUIRED--whether or not the regex
+              must be present or cannot be present.
+    """
+    self.regex = regex
+    self.included_extensions = included_extensions
+    self.skipped_patterns = UNIVERSALLY_SKIPPED_PATTERNS.union(skipped_patterns)
+    self.regex_type = regex_type
+
+  def fails(self, file):
+    """ Determine whether or not this file fails the regex check.
+
+    Args:
+        file: the full path of the file to check
+    """
+    if not file.endswith(self.included_extensions):
+      return False
+    for pattern in self.skipped_patterns:
+      if pattern in file:
+        return False
+    with open(file, "r") as f:
+      file_content = f.read()
+      matches = re.match(self.regex, file_content, re.DOTALL)
+      if self.regex_type == FORBIDDEN:
+        return matches
+      return not matches
+
+
+PRESUBMITS = {
+    # License check
+    PresubmitCheck(
+        r".*Copyright 20\d{2} The Nomulus Authors\. All Rights Reserved\.",
+        ("java", "js", "soy", "sql", "py", "sh"), {
+            ".git", "/build/", "/generated/", "node_modules/",
+            "JUnitBackports.java"
+        }, REQUIRED):
+        "File did not include the license header.",
+
+    # System.(out|err).println should only appear in tools/
+    PresubmitCheck(
+        r".*\bSystem\.(out|err)\.print", "java", {
+            "StackdriverDashboardBuilder.java", "/tools/", "/example/",
+            "RegistryTestServerMain.java", "TestServerRule.java",
+            "FlowDocumentationTool.java"
+        }):
+        "System.(out|err).println is only allowed in tools/ packages. Please "
+        "use a logger instead.",
+
+    # Various Soy linting checks
+    PresubmitCheck(
+        r".* (/\*)?\* {?@param ",
+        "soy",
+        {},
+    ):
+        "In SOY please use the ({@param name: string} /** User name. */) style"
+        " parameter passing instead of the ( * @param name User name.) style "
+        "parameter pasing.",
+    PresubmitCheck(
+        r'.*\{[^}]+\w+:\s+"',
+        "soy",
+        {},
+    ):
+        "Please don't use double-quoted string literals in Soy parameters",
+    PresubmitCheck(
+        r'.*autoescape\s*=\s*"[^s]',
+        "soy",
+        {},
+    ):
+        "All soy templates must use strict autoescaping",
+    PresubmitCheck(
+        r".*noAutoescape",
+        "soy",
+        {},
+    ):
+        "All soy templates must use strict autoescaping",
+
+    # various JS linting checks
+    PresubmitCheck(
+        r".*goog\.base\(",
+        "js",
+        {"/node_modules/"},
+    ):
+        "Use of goog.base is not allowed.",
+    PresubmitCheck(
+        r".*goog\.dom\.classes",
+        "js",
+        {"/node_modules/"},
+    ):
+        "Instead of goog.dom.classes, use goog.dom.classlist which is smaller "
+        "and faster.",
+    PresubmitCheck(
+        r".*goog\.getMsg",
+        "js",
+        {"/node_modules/"},
+    ):
+        "Put messages in Soy, instead of using goog.getMsg().",
+    PresubmitCheck(
+        r".*(innerHTML|outerHTML)\s*(=|[+]=)([^=]|$)",
+        "js",
+        {"/node_modules/"},
+    ):
+        "Do not assign directly to the dom. Use goog.dom.setTextContent to set"
+        " to plain text, goog.dom.removeChildren to clear, or "
+        "soy.renderElement to render anything else",
+    PresubmitCheck(
+        r".*console\.(log|info|warn|error)",
+        "js",
+        {"/node_modules/", "google/registry/ui/js/util.js"},
+    ):
+        "JavaScript files should not include console logging."
+}
+
+
+def get_files():
+  result = []
+  for root, dirnames, filenames in os.walk("."):
+    for filename in filenames:
+      yield os.path.join(root, filename)
+
+
+if __name__ == "__main__":
+  failed = False
+  for file in get_files():
+    error_messages = []
+    for presubmit, error_message in PRESUBMITS.items():
+      if presubmit.fails(file):
+        error_messages.append(error_message)
+
+    if error_messages:
+      failed = True
+      print("%s had errors: \n  %s" % (file, "\n  ".join(error_messages)))
+
+  if failed:
+    sys.exit(1)