Lint script (kensho-technologies#179)

* Write lint script

* Just testing the diff flag of the lint script

* Revert "Just testing the diff flag of the lint script"

This reverts commit 8e3b842.

* Implement proper pydocstyle config

* Update CONTRIBUTING docs to include the lint script.

* Add newlines at eof

* Use git -C

* Use lint script in travis

Author: bojanserafimov

.pydocstyle

@@ -1,2 +1,3 @@
 [pydocstyle]
 ignore = D100,D101,D104,D203,D213,D406,D407,D408,D409,D413
+match = '(?!test_).*\.py'

.pydocstyle_test

@@ -0,0 +1,3 @@
+[pydocstyle]
+ignore = D100,D101,D102,D104,D203,D213,D406,D407,D408,D409,D413
+match = 'test_.*\.py'

.travis.yml

@@ -21,11 +21,7 @@ matrix:
     python: "3.6"
     script:
       - pipenv run ./scripts/copyright_line_check.sh
-      - pipenv run isort --check-only --verbose --recursive graphql_compiler/
-      - pipenv run flake8 --config=setup.cfg graphql_compiler/
-      - pipenv run pydocstyle graphql_compiler/
-      - pipenv run pylint graphql_compiler/
-      - pipenv run bandit -r graphql_compiler/
+      - pipenv run ./scripts/lint.sh
   - name: "Python 2.7 unit tests"
     python: "2.7"
     script:

CONTRIBUTING.md

@@ -58,19 +58,7 @@ of both the contributors and the project.
 This project follows the
 [Google Python style guide](https://google.github.io/styleguide/pyguide.html).
 
-Additionally, any contributions must pass the following set of lint and style checks with no issues
-when executed from a pipenv shell (i.e. after running `pipenv shell`):
-```
-isort --check-only --verbose --recursive graphql_compiler/
-
-flake8 graphql_compiler/
-
-pydocstyle graphql_compiler/
-
-pylint graphql_compiler/
-
-bandit -r graphql_compiler/
-```
+Additionally, any contributions must pass the linter `scripts/lint.sh` when executed from a pipenv shell (i.e. after running `pipenv shell`). To run the linter on changed files only, commit your changes and run `scripts/lint.sh --diff`.
 
 Finally, all python files in the repository must display the copyright of the project,
 to protect the terms of the license. Please make sure that your files start with a line like:

scripts/lint.sh

@@ -0,0 +1,88 @@
+#!/usr/bin/env bash
+
+# Treat undefined variables and non-zero exits in pipes as errors.
+set -uo pipefail
+
+# Ensure that the "**" glob operator is applied recursively.
+shopt -s globstar
+
+# Break on first error.
+set -e
+
+# Parse input arguments.
+diff_only=0
+for i in "$@"; do
+    case $i in
+        --diff )
+            diff_only=1
+            shift;;
+
+        *)
+            echo "Unknown option: $i";
+            exit 1;;
+    esac
+done
+
+# Make sure the current working directory for this script is the root directory.
+cd "$(git -C "$(dirname "${0}")" rev-parse --show-toplevel )"
+
+# Get all python files or directories that need to be linted.
+lintable_locations="graphql_compiler/"
+# pylint doesn't support linting directories that aren't packages:
+# https://github.com/PyCQA/pylint/issues/352
+# Use **/*.py to supply all python files for individual linting.
+pylint_lintable_locations="graphql_compiler/**/*.py"
+if [ "$diff_only" -eq 1 ] ; then
+    # Quotes don't need to be escaped because they nest with $( ).
+    lintable_locations="$(git diff --name-only master... | grep "\.*\.py$")"
+    pylint_lintable_locations="$lintable_locations"
+fi
+
+# Continue on error to allow ignoring certain linters.
+# Errors are manually aggregated at the end.
+set +e
+
+echo -e '*** Running isort... ***\n'
+isort --check-only --recursive graphql_compiler/
+isort_exit_code=$?
+echo -e "\n*** End of isort run; exit: $isort_exit_code ***\n"
+
+echo -e '*** Running flake8... ***\n'
+flake8 $lintable_locations
+flake_exit_code=$?
+echo -e "\n*** End of flake8 run, exit: $flake_exit_code ***\n"
+
+echo -e '\n*** Running pydocstyle... ***\n'
+pydocstyle --config=.pydocstyle $lintable_locations
+pydocstyle_exit_code=$?
+pydocstyle --config=.pydocstyle_test $lintable_locations
+pydocstyle_test_exit_code=$?
+echo -e "\n*** End of pydocstyle run, exit: $pydocstyle_exit_code ***\n"
+
+echo -e '\n*** Running pylint... ***\n'
+pylint $pylint_lintable_locations
+pylint_exit_code=$?
+echo -e "\n*** End of pylint run, exit: $pylint_exit_code ***\n"
+
+echo -e '\n*** Running bandit... ***\n'
+bandit -r $lintable_locations
+bandit_exit_code=$?
+echo -e "\n*** End of bandit run, exit: $bandit_exit_code ***\n"
+
+if [[ ("$flake_exit_code" != "0") ||
+      ("$pydocstyle_exit_code" != "0") ||
+      ("$pydocstyle_test_exit_code" != "0") ||
+      ("$pylint_exit_code" != "0") ||
+      ("$bandit_exit_code" != "0") ||
+      ("$isort_exit_code" != "0") ]]; then
+    echo -e "\n*** Lint failed. ***\n"
+    echo -e "isort exit: $isort_exit_code"
+    echo -e "flake8 exit: $flake_exit_code"
+    echo -e "pydocstyle exit: $pydocstyle_exit_code"
+    echo -e "pydocstyle test exit: $pydocstyle_test_exit_code"
+    echo -e "pylint exit: $pylint_exit_code"
+    echo -e "bandit exit: $bandit_exit_code"
+    exit 1
+fi
+
+echo -e "\n*** Lint successful. ***\n"