Enhance Jenkins integration of safe templates take 2

- Handle case when no files are linted
- Skip deleted files for safe commit script
- Add verbose options for safe commit

pavelib/paver_tests/test_paver_quality.py

@@ -4,6 +4,7 @@ Tests for paver quality tasks
 import os
 from path import Path as path
 import tempfile
+import textwrap
 import unittest
 from mock import patch, MagicMock, mock_open
 from ddt import ddt, file_data
@@ -59,7 +60,8 @@ class TestPaverQualityViolations(unittest.TestCase):
 
 class TestPaverReportViolationsCounts(unittest.TestCase):
     """
-    For testing run_jshint and run_complexity utils
+    For testing utility functions for getting counts from reports for
+    run_jshint, run_complexity, run_safelint, and run_safecommit_report.
     """
 
     def setUp(self):
@@ -132,6 +134,91 @@ class TestPaverReportViolationsCounts(unittest.TestCase):
         actual_count = pavelib.quality._get_count_from_last_line(self.f.name, "foo")  # pylint: disable=protected-access
         self.assertEqual(actual_count, None)
 
+    def test_get_safelint_counts_happy(self):
+        """
+        Test happy path getting violation counts from safelint report.
+        """
+        report = textwrap.dedent("""
+            test.html: 30:53: javascript-jquery-append:  $('#test').append(print_tos);
+
+            javascript-concat-html: 310 violations
+            javascript-escape:      7 violations
+
+            2608 violations total
+        """)
+        with open(self.f.name, 'w') as f:
+            f.write(report)
+        counts = pavelib.quality._get_safelint_counts(self.f.name)  # pylint: disable=protected-access
+        self.assertDictEqual(counts, {
+            'rules': {
+                'javascript-concat-html': 310,
+                'javascript-escape': 7,
+            },
+            'total': 2608,
+        })
+
+    def test_get_safelint_counts_bad_counts(self):
+        """
+        Test getting violation counts from truncated and malformed safelint
+        report.
+        """
+        report = textwrap.dedent("""
+            javascript-concat-html: violations
+        """)
+        with open(self.f.name, 'w') as f:
+            f.write(report)
+        counts = pavelib.quality._get_safelint_counts(self.f.name)  # pylint: disable=protected-access
+        self.assertDictEqual(counts, {
+            'rules': {},
+            'total': None,
+        })
+
+    def test_get_safecommit_count_happy(self):
+        """
+        Test happy path getting violation count from safecommit report.
+        """
+        report = textwrap.dedent("""
+            Linting lms/templates/navigation.html:
+
+            2 violations total
+
+            Linting scripts/tests/templates/test.underscore:
+
+            3 violations total
+        """)
+        with open(self.f.name, 'w') as f:
+            f.write(report)
+        count = pavelib.quality._get_safecommit_count(self.f.name)  # pylint: disable=protected-access
+
+        self.assertEqual(count, 5)
+
+    def test_get_safecommit_count_bad_counts(self):
+        """
+        Test getting violation count from truncated safecommit report.
+        """
+        report = textwrap.dedent("""
+            Linting lms/templates/navigation.html:
+        """)
+        with open(self.f.name, 'w') as f:
+            f.write(report)
+        count = pavelib.quality._get_safecommit_count(self.f.name)  # pylint: disable=protected-access
+
+        self.assertIsNone(count)
+
+    def test_get_safecommit_count_no_files(self):
+        """
+        Test getting violation count from safecommit report where no files were
+        linted.
+        """
+        report = textwrap.dedent("""
+            No files linted.
+        """)
+        with open(self.f.name, 'w') as f:
+            f.write(report)
+        count = pavelib.quality._get_safecommit_count(self.f.name)  # pylint: disable=protected-access
+
+        self.assertEqual(count, 0)
+
 
 class TestPrepareReportDir(unittest.TestCase):
     """

pavelib/paver_tests/test_safecommit.py

+"""
+Tests for paver safecommit quality tasks
+"""
+from mock import patch
+
+import pavelib.quality
+from paver.easy import call_task
+
+from .utils import PaverTestCase
+
+
+class PaverSafeCommitTest(PaverTestCase):
+    """
+    Test run_safecommit_report with a mocked environment in order to pass in
+    opts.
+
+    """
+
+    def setUp(self):
+        super(PaverSafeCommitTest, self).setUp()
+        self.reset_task_messages()
+
+    @patch.object(pavelib.quality, '_write_metric')
+    @patch.object(pavelib.quality, '_prepare_report_dir')
+    @patch.object(pavelib.quality, '_get_safecommit_count')
+    def test_safecommit_violation_number_not_found(self, _mock_count, _mock_report_dir, _mock_write_metric):
+        """
+        run_safecommit_report encounters an error parsing the safecommit output
+        log.
+
+        """
+        _mock_count.return_value = None
+        with self.assertRaises(SystemExit):
+            call_task('pavelib.quality.run_safecommit_report')
+
+    @patch.object(pavelib.quality, '_write_metric')
+    @patch.object(pavelib.quality, '_prepare_report_dir')
+    @patch.object(pavelib.quality, '_get_safecommit_count')
+    def test_safecommit_vanilla(self, _mock_count, _mock_report_dir, _mock_write_metric):
+        """
+        run_safecommit_report finds violations.
+        """
+        _mock_count.return_value = 0
+        call_task('pavelib.quality.run_safecommit_report')

pavelib/paver_tests/test_safelint.py

 """
-Tests for paver quality tasks
+Tests for paver safelint quality tasks
 """
 from mock import patch
 
@@ -20,43 +20,99 @@ class PaverSafeLintTest(PaverTestCase):
 
     @patch.object(pavelib.quality, '_write_metric')
     @patch.object(pavelib.quality, '_prepare_report_dir')
-    @patch.object(pavelib.quality, '_get_count_from_last_line')
-    def test_safelint_violation_number_not_found(self, _mock_count, _mock_report_dir, _mock_write_metric):
+    @patch.object(pavelib.quality, '_get_safelint_counts')
+    def test_safelint_violation_number_not_found(self, _mock_counts, _mock_report_dir, _mock_write_metric):
         """
         run_safelint encounters an error parsing the safelint output log
         """
-        _mock_count.return_value = None
+        _mock_counts.return_value = {}
         with self.assertRaises(SystemExit):
             call_task('pavelib.quality.run_safelint')
 
     @patch.object(pavelib.quality, '_write_metric')
     @patch.object(pavelib.quality, '_prepare_report_dir')
-    @patch.object(pavelib.quality, '_get_count_from_last_line')
-    def test_safelint_vanilla(self, _mock_count, _mock_report_dir, _mock_write_metric):
+    @patch.object(pavelib.quality, '_get_safelint_counts')
+    def test_safelint_vanilla(self, _mock_counts, _mock_report_dir, _mock_write_metric):
         """
         run_safelint finds violations, but a limit was not set
         """
-        _mock_count.return_value = 1
+        _mock_counts.return_value = {'total': 0}
         call_task('pavelib.quality.run_safelint')
 
     @patch.object(pavelib.quality, '_write_metric')
     @patch.object(pavelib.quality, '_prepare_report_dir')
-    @patch.object(pavelib.quality, '_get_count_from_last_line')
-    def test_safelint_too_many_violations(self, _mock_count, _mock_report_dir, _mock_write_metric):
+    @patch.object(pavelib.quality, '_get_safelint_counts')
+    def test_safelint_invalid_thresholds_option(self, _mock_counts, _mock_report_dir, _mock_write_metric):
+        """
+        run_safelint fails when thresholds option is poorly formatted
+        """
+        _mock_counts.return_value = {'total': 0}
+        with self.assertRaises(SystemExit):
+            call_task('pavelib.quality.run_safelint', options={"thresholds": "invalid"})
+
+    @patch.object(pavelib.quality, '_write_metric')
+    @patch.object(pavelib.quality, '_prepare_report_dir')
+    @patch.object(pavelib.quality, '_get_safelint_counts')
+    def test_safelint_invalid_thresholds_option_key(self, _mock_counts, _mock_report_dir, _mock_write_metric):
+        """
+        run_safelint fails when thresholds option is poorly formatted
+        """
+        _mock_counts.return_value = {'total': 0}
+        with self.assertRaises(SystemExit):
+            call_task('pavelib.quality.run_safelint', options={"thresholds": '{"invalid": 3}'})
+
+    @patch.object(pavelib.quality, '_write_metric')
+    @patch.object(pavelib.quality, '_prepare_report_dir')
+    @patch.object(pavelib.quality, '_get_safelint_counts')
+    def test_safelint_too_many_violations(self, _mock_counts, _mock_report_dir, _mock_write_metric):
         """
         run_safelint finds more violations than are allowed
         """
-        _mock_count.return_value = 4
+        _mock_counts.return_value = {'total': 4}
         with self.assertRaises(SystemExit):
-            call_task('pavelib.quality.run_safelint', options={"limit": "3"})
+            call_task('pavelib.quality.run_safelint', options={"thresholds": '{"total": 3}'})
 
     @patch.object(pavelib.quality, '_write_metric')
     @patch.object(pavelib.quality, '_prepare_report_dir')
-    @patch.object(pavelib.quality, '_get_count_from_last_line')
-    def test_safelint_under_limit(self, _mock_count, _mock_report_dir, _mock_write_metric):
+    @patch.object(pavelib.quality, '_get_safelint_counts')
+    def test_safelint_under_limit(self, _mock_counts, _mock_report_dir, _mock_write_metric):
         """
         run_safelint finds fewer violations than are allowed
         """
-        _mock_count.return_value = 4
+        _mock_counts.return_value = {'total': 4}
+        # No System Exit is expected
+        call_task('pavelib.quality.run_safelint', options={"thresholds": '{"total": 5}'})
+
+    @patch.object(pavelib.quality, '_write_metric')
+    @patch.object(pavelib.quality, '_prepare_report_dir')
+    @patch.object(pavelib.quality, '_get_safelint_counts')
+    def test_safelint_rule_violation_number_not_found(self, _mock_counts, _mock_report_dir, _mock_write_metric):
+        """
+        run_safelint encounters an error parsing the safelint output log for a
+        given rule threshold that was set.
+        """
+        _mock_counts.return_value = {'total': 4}
+        with self.assertRaises(SystemExit):
+            call_task('pavelib.quality.run_safelint', options={"thresholds": '{"rules": {"javascript-escape": 3}}'})
+
+    @patch.object(pavelib.quality, '_write_metric')
+    @patch.object(pavelib.quality, '_prepare_report_dir')
+    @patch.object(pavelib.quality, '_get_safelint_counts')
+    def test_safelint_too_many_rule_violations(self, _mock_counts, _mock_report_dir, _mock_write_metric):
+        """
+        run_safelint finds more rule violations than are allowed
+        """
+        _mock_counts.return_value = {'total': 4, 'rules': {'javascript-escape': 4}}
+        with self.assertRaises(SystemExit):
+            call_task('pavelib.quality.run_safelint', options={"thresholds": '{"rules": {"javascript-escape": 3}}'})
+
+    @patch.object(pavelib.quality, '_write_metric')
+    @patch.object(pavelib.quality, '_prepare_report_dir')
+    @patch.object(pavelib.quality, '_get_safelint_counts')
+    def test_safelint_under_rule_limit(self, _mock_counts, _mock_report_dir, _mock_write_metric):
+        """
+        run_safelint finds fewer rule violations than are allowed
+        """
+        _mock_counts.return_value = {'total': 4, 'rules': {'javascript-escape': 4}}
         # No System Exit is expected
-        call_task('pavelib.quality.run_safelint', options={"limit": "5"})
+        call_task('pavelib.quality.run_safelint', options={"thresholds": '{"rules": {"javascript-escape": 5}}'})

pavelib/quality.py

@@ -2,6 +2,7 @@
 Check code quality using pep8, pylint, and diff_quality.
 """
 from paver.easy import sh, task, cmdopts, needs, BuildFailure
+import json
 import os
 import re
 
@@ -135,8 +136,8 @@ def run_pylint(options):
 
     # Fail number of violations is greater than the limit
     if num_violations > violations_limit > -1:
-        raise Exception("Failed. Too many pylint violations. "
-                        "The limit is {violations_limit}.".format(violations_limit=violations_limit))
+        raise BuildFailure("Failed. Too many pylint violations. "
+                           "The limit is {violations_limit}.".format(violations_limit=violations_limit))
 
 
 def _count_pylint_violations(report_file):
@@ -218,7 +219,7 @@ def run_pep8(options):  # pylint: disable=unused-argument
     if count:
         failure_string = "Too many pep8 violations. " + violations_count_str
         failure_string += "\n\nViolations:\n{violations_list}".format(violations_list=violations_list)
-        raise Exception(failure_string)
+        raise BuildFailure(failure_string)
 
 
 @task
@@ -293,7 +294,7 @@ def run_jshint(options):
 
     # Fail if number of violations is greater than the limit
     if num_violations > violations_limit > -1:
-        raise Exception(
+        raise BuildFailure(
             "JSHint Failed. Too many violations ({count}).\nThe limit is {violations_limit}.".format(
                 count=num_violations, violations_limit=violations_limit
             )
@@ -303,48 +304,150 @@ def run_jshint(options):
 @task
 @needs('pavelib.prereqs.install_python_prereqs')
 @cmdopts([
-    ("limit=", "l", "limit for number of acceptable violations"),
+    ("thresholds=", "t", "json containing limit for number of acceptable violations per rule"),
 ])
 def run_safelint(options):
     """
     Runs safe_template_linter.py on the codebase
     """
 
-    violations_limit = int(getattr(options, 'limit', -1))
+    thresholds_option = getattr(options, 'thresholds', '{}')
+    try:
+        violation_thresholds = json.loads(thresholds_option)
+    except ValueError:
+        violation_thresholds = None
+    if isinstance(violation_thresholds, dict) is False or \
+            any(key not in ("total", "rules") for key in violation_thresholds.keys()):
 
+        raise BuildFailure(
+            """Error. Thresholds option "{thresholds_option}" was not supplied using proper format.\n"""
+            """Here is a properly formatted example, '{{"total":100,"rules":{{"javascript-escape":0}}}}' """
+            """with property names in double-quotes.""".format(
+                thresholds_option=thresholds_option
+            )
+        )
+
+    safelint_script = "safe_template_linter.py"
     safelint_report_dir = (Env.REPORT_DIR / "safelint")
     safelint_report = safelint_report_dir / "safelint.report"
     _prepare_report_dir(safelint_report_dir)
 
     sh(
-        "{repo_root}/scripts/safe_template_linter.py >> {safelint_report}".format(
+        "{repo_root}/scripts/{safelint_script} --rule-totals >> {safelint_report}".format(
             repo_root=Env.REPO_ROOT,
+            safelint_script=safelint_script,
             safelint_report=safelint_report,
         ),
         ignore_error=True
     )
 
+    safelint_counts = _get_safelint_counts(safelint_report)
+
     try:
-        num_violations = int(_get_count_from_last_line(safelint_report, "safelint"))
+        metrics_str = "Number of {safelint_script} violations: {num_violations}\n".format(
+            safelint_script=safelint_script, num_violations=int(safelint_counts['total'])
+        )
+        if 'rules' in safelint_counts and any(safelint_counts['rules']):
+            metrics_str += "\n"
+            rule_keys = sorted(safelint_counts['rules'].keys())
+            for rule in rule_keys:
+                metrics_str += "{rule} violations: {count}\n".format(
+                    rule=rule,
+                    count=int(safelint_counts['rules'][rule])
+                )
     except TypeError:
         raise BuildFailure(
-            "Error. Number of safelint violations could not be found in {safelint_report}".format(
-                safelint_report=safelint_report
+            "Error. Number of {safelint_script} violations could not be found in {safelint_report}".format(
+                safelint_script=safelint_script, safelint_report=safelint_report
             )
         )
 
+    metrics_report = (Env.METRICS_DIR / "safelint")
     # Record the metric
-    _write_metric(num_violations, (Env.METRICS_DIR / "safelint"))
+    _write_metric(metrics_str, metrics_report)
+    # Print number of violations to log.
+    sh("cat {metrics_report}".format(metrics_report=metrics_report), ignore_error=True)
 
-    # Fail if number of violations is greater than the limit
-    if num_violations > violations_limit > -1:
-        raise Exception(
-            "SafeTemplateLinter Failed. Too many violations ({count}).\nThe limit is {violations_limit}.".format(
-                count=num_violations, violations_limit=violations_limit
+    error_message = ""
+
+    # Test total violations against threshold.
+    if 'total' in violation_thresholds.keys():
+        if violation_thresholds['total'] < safelint_counts['total']:
+            error_message = "Too many violations total ({count}).\nThe limit is {violations_limit}.".format(
+                count=safelint_counts['total'], violations_limit=violation_thresholds['total']
+            )
+
+    # Test rule violations against thresholds.
+    if 'rules' in violation_thresholds:
+        threshold_keys = sorted(violation_thresholds['rules'].keys())
+        for threshold_key in threshold_keys:
+            if threshold_key not in safelint_counts['rules']:
+                error_message += (
+                    "\nNumber of {safelint_script} violations for {rule} could not be found in "
+                    "{safelint_report}."
+                ).format(
+                    safelint_script=safelint_script, rule=threshold_key, safelint_report=safelint_report
+                )
+            elif violation_thresholds['rules'][threshold_key] < safelint_counts['rules'][threshold_key]:
+                error_message += \
+                    "\nToo many {rule} violations ({count}).\nThe {rule} limit is {violations_limit}.".format(
+                        rule=threshold_key, count=safelint_counts['rules'][threshold_key],
+                        violations_limit=violation_thresholds['rules'][threshold_key],
+                    )
+
+    if error_message is not "":
+        raise BuildFailure(
+            "SafeTemplateLinter Failed.\n{error_message}\n"
+            "See {safelint_report} or run the following command to hone in on the problem:\n"
+            "  ./scripts/safe-commit-linter.sh -h".format(
+                error_message=error_message, safelint_report=safelint_report
             )
         )
 
 
+@task
+@needs('pavelib.prereqs.install_python_prereqs')
+def run_safecommit_report():
+    """
+    Runs safe-commit-linter.sh on the current branch.
+    """
+    safecommit_script = "safe-commit-linter.sh"
+    safecommit_report_dir = (Env.REPORT_DIR / "safecommit")
+    safecommit_report = safecommit_report_dir / "safecommit.report"
+    _prepare_report_dir(safecommit_report_dir)
+
+    sh(
+        "{repo_root}/scripts/{safecommit_script} | tee {safecommit_report}".format(
+            repo_root=Env.REPO_ROOT,
+            safecommit_script=safecommit_script,
+            safecommit_report=safecommit_report,
+        ),
+        ignore_error=True
+    )
+
+    safecommit_count = _get_safecommit_count(safecommit_report)
+
+    try:
+        num_violations = int(safecommit_count)
+    except TypeError:
+        raise BuildFailure(
+            "Error. Number of {safecommit_script} violations could not be found in {safecommit_report}".format(
+                safecommit_script=safecommit_script, safecommit_report=safecommit_report
+            )
+        )
+
+    # Print number of violations to log.
+    violations_count_str = "Number of {safecommit_script} violations: {num_violations}\n".format(
+        safecommit_script=safecommit_script, num_violations=num_violations
+    )
+
+    # Record the metric
+    metrics_report = (Env.METRICS_DIR / "safecommit")
+    _write_metric(violations_count_str, metrics_report)
+    # Output report to console.
+    sh("cat {metrics_report}".format(metrics_report=metrics_report), ignore_error=True)
+
+
 def _write_metric(metric, filename):
     """
     Write a given metric to a given file
@@ -363,15 +466,28 @@ def _prepare_report_dir(dir_name):
     dir_name.mkdir_p()
 
 
-def _get_last_report_line(filename):
+def _get_report_contents(filename, last_line_only=False):
     """
-    Returns the last line of a given file. Used for getting output from quality output files.
+    Returns the contents of the given file. Use last_line_only to only return
+    the last line, which can be used for getting output from quality output
+    files.
+
+    Arguments:
+        last_line_only: True to return the last line only, False to return a
+            string with full contents.
+
+    Returns:
+        String containing full contents of the report, or the last line.
+
     """
     file_not_found_message = "The following log file could not be found: {file}".format(file=filename)
     if os.path.isfile(filename):
         with open(filename, 'r') as report_file:
-            lines = report_file.readlines()
-            return lines[len(lines) - 1]
+            if last_line_only:
+                lines = report_file.readlines()
+                return lines[len(lines) - 1]
+            else:
+                return report_file.read()
     else:
         # Raise a build error if the file is not found
         raise BuildFailure(file_not_found_message)
@@ -382,7 +498,7 @@ def _get_count_from_last_line(filename, file_type):
     This will return the number in the last line of a file.
     It is returning only the value (as a floating number).
     """
-    last_line = _get_last_report_line(filename)
+    last_line = _get_report_contents(filename, last_line_only=True)
     if file_type is "python_complexity":
         # Example of the last line of a complexity report: "Average complexity: A (1.93953443446)"
         regex = r'\d+.\d+'
@@ -398,6 +514,66 @@ def _get_count_from_last_line(filename, file_type):
         return None
 
 
+def _get_safelint_counts(filename):
+    """
+    This returns a dict of violations from the safelint report.
+
+    Arguments:
+        filename: The name of the safelint report.
+
+    Returns:
+        A dict containing the following:
+            rules: A dict containing the count for each rule as follows:
+                violation-rule-id: N, where N is the number of violations
+            total: M, where M is the number of total violations
+
+    """
+    report_contents = _get_report_contents(filename)
+    rule_count_regex = re.compile(r"^(?P<rule_id>[a-z-]+):\s+(?P<count>\d+) violations", re.MULTILINE)
+    total_count_regex = re.compile(r"^(?P<count>\d+) violations total", re.MULTILINE)
+    violations = {'rules': {}}
+    for violation_match in rule_count_regex.finditer(report_contents):
+        try:
+            violations['rules'][violation_match.group('rule_id')] = int(violation_match.group('count'))
+        except ValueError:
+            violations['rules'][violation_match.group('rule_id')] = None
+    try:
+        violations['total'] = int(total_count_regex.search(report_contents).group('count'))
+    # An AttributeError will occur if the regex finds no matches.
+    # A ValueError will occur if the returned regex cannot be cast as a float.
+    except (AttributeError, ValueError):
+        violations['total'] = None
+    return violations
+
+
+def _get_safecommit_count(filename):
+    """
+    Returns the violation count from the safecommit report.
+
+    Arguments:
+        filename: The name of the safecommit report.
+
+    Returns:
+        The count of safecommit violations, or None if there is  a problem.
+
+    """
+    report_contents = _get_report_contents(filename)
+
+    if 'No files linted' in report_contents:
+        return 0
+
+    file_count_regex = re.compile(r"^(?P<count>\d+) violations total", re.MULTILINE)
+    try:
+        validation_count = None
+        for count_match in file_count_regex.finditer(report_contents):
+            if validation_count is None:
+                validation_count = 0
+            validation_count += int(count_match.group('count'))
+        return validation_count
+    except ValueError:
+        return None
+
+
 @task
 @needs('pavelib.prereqs.install_python_prereqs')
 @cmdopts([

scripts/all-tests.sh

@@ -13,7 +13,9 @@ set -e
 # Violations thresholds for failing the build
 export PYLINT_THRESHOLD=4175
 export JSHINT_THRESHOLD=7550
-export SAFELINT_THRESHOLD=2700
+
+SAFELINT_THRESHOLDS=`cat scripts/safelint_thresholds.json`
+export SAFELINT_THRESHOLDS=${SAFELINT_THRESHOLDS//[[:space:]]/}
 
 doCheckVars() {
     if [ -n "$CIRCLECI" ] ; then

scripts/generic-ci-tests.sh

@@ -85,7 +85,9 @@ case "$TEST_SUITE" in
         echo "Running code complexity report (python)."
         paver run_complexity > reports/code_complexity.log || echo "Unable to calculate code complexity. Ignoring error."
         echo "Running safe template linter report."
-        paver run_safelint -l $SAFELINT_THRESHOLD > safelint.log || { cat safelint.log; EXIT=1; }
+        paver run_safelint -t $SAFELINT_THRESHOLDS > safelint.log || { cat safelint.log; EXIT=1; }
+        echo "Running safe commit linter report."
+        paver run_safecommit_report > safecommit.log || { cat safecommit.log; EXIT=1; }
         # Run quality task. Pass in the 'fail-under' percentage to diff-quality
         echo "Running diff quality."
         paver run_quality -p 100 || EXIT=1

scripts/safe-commit-linter.sh

@@ -19,6 +19,7 @@ show_help() {
     echo "  -m, --main-branch=COMMIT    Run against files changed between the"
     echo "                              current branch and this commit."
     echo "                              Defaults to origin/master."
+    echo "  -v, --verbose               Output details of git commands run."
     echo ""
     echo "This scripts does not give a grand total.  Be sure to check for"
     echo "0 violations on each file."
@@ -30,12 +31,25 @@ show_help() {
 
 }
 
+show_verbose() {
+    echo "Files linted is based on the following:"
+    echo "- Current commit: ${current_branch_hash}"
+    echo "- Main commit: ${MAIN_COMMIT}"
+    echo "- Merge base command: ${merge_base_command}"
+    echo "- Merge base: ${merge_base}"
+    echo "- Diff command: ${diff_command}"
+
+}
+
 for i in "$@"; do
     case $i in
         -m=*|--main-branch=*)
             MAIN_COMMIT="${i#*=}"
             shift # past argument=value
             ;;
+        -v|--verbose)
+            VERBOSE=true
+            ;;
         -h|--help|*)
             # help or unknown option
             show_help
@@ -51,11 +65,24 @@ if [ -z "${MAIN_COMMIT+x}" ]; then
     MAIN_COMMIT="origin/master"
 fi
 
-merge_base=`git merge-base "$current_branch_hash" "$MAIN_COMMIT"`
-diff_files=`git diff --name-only "$current_branch_hash" "$merge_base"`
+merge_base_command="git merge-base $current_branch_hash $MAIN_COMMIT"
+merge_base=$(${merge_base_command})
+diff_command="git diff --name-only --diff-filter=ACM $current_branch_hash $merge_base"
+diff_files=$(${diff_command})
 
-for f in $diff_files; do
+if [ "$diff_files" = "" ]; then
+    # When no files are found, automatically display verbose details to help
+    # understand why.
+    show_verbose
     echo ""
-    echo "Linting $f:"
-    ./scripts/safe_template_linter.py $f
-done
+    echo "No files linted."
+else
+    if [ ${VERBOSE} ] ; then
+        show_verbose
+    fi
+    for f in $diff_files; do
+        echo ""
+        echo "Linting $f:"
+        ./scripts/safe_template_linter.py $f
+    done
+fi

scripts/safelint_thresholds.json

+{
+    "rules": {
+        "javascript-concat-html": 313,
+        "javascript-escape": 7,
+        "javascript-interpolate": 71,
+        "javascript-jquery-append": 120,
+        "javascript-jquery-html": 313,
+        "javascript-jquery-insert-into-target": 26,
+        "javascript-jquery-insertion": 30,
+        "javascript-jquery-prepend": 12,
+        "mako-html-entities": 0,
+        "mako-invalid-html-filter": 33,
+        "mako-invalid-js-filter": 222,
+        "mako-js-html-string": 0,
+        "mako-js-missing-quotes": 0,
+        "mako-missing-default": 234,
+        "mako-multiple-page-tags": 0,
+        "mako-unknown-context": 0,
+        "mako-unparseable-expression": 0,
+        "mako-unwanted-html-filter": 0,
+        "python-close-before-format": 0,
+        "python-concat-html": 28,
+        "python-custom-escape": 13,
+        "python-deprecated-display-name": 53,
+        "python-interpolate-html": 68,
+        "python-parse-error": 0,
+        "python-requires-html-or-text": 0,
+        "python-wrap-html": 279,
+        "underscore-not-escaped": 709
+    },
+    "total": 2509
+}