From 6b69cc0b3948e69d00fbf38d487b367e23e5c619 Mon Sep 17 00:00:00 2001
From: Tim Abbott <tabbott@zulipchat.com>
Date: Sun, 16 Dec 2018 20:58:06 -0800
Subject: [PATCH] lint: Run mypy as part of main linter.

To support this, we add a pass_targets option to the main linter
library, because with current mypy, it's generally counterproductive
to pass the list of files in (can produce spurious errors; isn't
faster).
---
 docs/testing/linters.md |  9 +++------
 tools/ci/backend        |  2 +-
 tools/lint              |  5 +++++
 tools/test-all          |  1 -
 tools/zulint/command.py | 10 +++++++---
 5 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/docs/testing/linters.md b/docs/testing/linters.md
index a528e38c2c..36f6065a35 100644
--- a/docs/testing/linters.md
+++ b/docs/testing/linters.md
@@ -99,12 +99,9 @@ following checks:
 - Check HTML templates for matching tags and indentations.
 - Check CSS for parsability and formatting.
 - Check JavaScript code for addClass calls.
-
-The remaining lint checks occur in `./tools/run-mypy`.  It is probably somewhat
-of an understatement to call "mypy" a "linter," as it performs static
-code analysis of Python type annotations throughout our Python codebase.
-
-Our [documentation on using mypy](../testing/mypy.html) covers mypy in more detail.
+- Running `mypy` to check static types in Python code.  Our
+  [documentation on using mypy](../testing/mypy.html) covers mypy in
+  more detail.
 
 The rest of this document pertains to the checks that occur in `./tools/lint`.
 
diff --git a/tools/ci/backend b/tools/ci/backend
index 2b2de42ba5..477815f242 100755
--- a/tools/ci/backend
+++ b/tools/ci/backend
@@ -6,7 +6,7 @@ echo "Test suite is running under $(python --version)."
 set -e
 set -x
 
-./tools/lint --backend --no-gitlint  # gitlint disabled because flaky
+./tools/lint --backend --no-gitlint --no-mypy  # gitlint disabled because flaky
 ./tools/test-tools
 ./tools/test-backend --coverage
 
diff --git a/tools/lint b/tools/lint
index 8328d861e6..1e4d83e6a3 100755
--- a/tools/lint
+++ b/tools/lint
@@ -27,6 +27,9 @@ def run():
     parser.add_argument('--no-gitlint',
                         action='store_true',
                         help='Disable gitlint')
+    parser.add_argument('--no-mypy',
+                        action='store_true',
+                        help='Disable mypy')
     limited_tests_group = parser.add_mutually_exclusive_group()
     limited_tests_group.add_argument('--frontend',
                                      action='store_true',
@@ -98,6 +101,8 @@ def run():
     linter_config.external_linter('urls', ['tools/check-urls'], ['py'])
     linter_config.external_linter('swagger', ['node', 'tools/check-swagger'], ['yaml'])
     linter_config.external_linter('shellcheck', ['shellcheck', '-x'], ['sh'])
+    if not args.no_mypy:
+        linter_config.external_linter('mypy', ['tools/run-mypy'], ['py'], pass_targets=False)
 
     # Disabled check for imperative mood until it is stabilized
     if not args.no_gitlint:
diff --git a/tools/test-all b/tools/test-all
index c587e70126..ad7d8f1507 100755
--- a/tools/test-all
+++ b/tools/test-all
@@ -42,7 +42,6 @@ run ./tools/clean-repo
 run ./tools/lint --backend $FORCEARG
 run ./tools/test-tools
 run ./tools/test-backend $FORCEARG
-run ./tools/run-mypy $FORCEARG
 run ./tools/test-migrations
 # Not running SVG optimizing since it's low-churn
 # run ./tools/setup/optimize-svg
diff --git a/tools/zulint/command.py b/tools/zulint/command.py
index 6343fe6564..51322c845b 100644
--- a/tools/zulint/command.py
+++ b/tools/zulint/command.py
@@ -57,8 +57,8 @@ class LinterConfig:
         self.lint_functions[func.__name__] = func
         return func
 
-    def external_linter(self, name, command, target_langs=[]):
-        # type: (str, List[str], List[str]) -> None
+    def external_linter(self, name, command, target_langs=[], pass_targets=True):
+        # type: (str, List[str], List[str], bool) -> None
         """Registers an external linter program to be run as part of the
         linter.  This program will be passed the subset of files being
         linted that have extensions in target_langs.  If there are no
@@ -80,7 +80,11 @@ class LinterConfig:
                     # invoking the external linter.
                     return 0
 
-            p = subprocess.Popen(command + targets,
+            if pass_targets:
+                full_command = command + targets
+            else:
+                full_command = command
+            p = subprocess.Popen(full_command,
                                  stdout=subprocess.PIPE,
                                  stderr=subprocess.STDOUT)