test_script: Move Puppeteer downloads outside node_modules.

This way Puppeteer doesn’t have to re-download Chromium every time we
install new JavaScript dependencies.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

requirements/dev.in

@@ -78,3 +78,6 @@ natsort
 
 # For spell check linter
 codespell
+
+# Finds appropriate directories for data, config, cache, etc.
+platformdirs

requirements/dev.txt

@@ -1288,7 +1288,9 @@ pkgutil-resolve-name==1.3.10 \
 platformdirs==2.5.2 \
     --hash=sha256:027d8e83a2d7de06bbac4e5ef7e023c02b863d7ea5d079477e722bb41ab25788 \
     --hash=sha256:58c8abb07dcb441e6ee4b11d8df0ac856038f944ab98b7be6b27b2a3c7feef19
-    # via black
+    # via
+    #   -r requirements/dev.in
+    #   black
 polib==1.1.1 \
     --hash=sha256:d3ee85e0c6788f789353416b1612c6c92d75fe6ccfac0029711974d6abd0f86d \
     --hash=sha256:e02c355ae5e054912e3b0d16febc56510eff7e49d60bf22aecb463bd2f2a2dfa

tools/lib/test_script.py

@@ -5,6 +5,8 @@ import sys
 from argparse import ArgumentParser
 from typing import Iterable, List, Optional, Tuple
 
+import platformdirs
+
 from scripts.lib.zulip_tools import get_dev_uuid_var_path
 from version import PROVISION_VERSION
 
@@ -120,6 +122,9 @@ def find_js_test_files(test_dir: str, files: Iterable[str]) -> List[str]:
 
 def prepare_puppeteer_run(is_firefox: bool = False) -> None:
     os.chdir(ZULIP_PATH)
+    download_path = platformdirs.user_cache_dir("zulip/puppeteer-download")
+    os.makedirs(download_path)
+    os.environ["PUPPETEER_DOWNLOAD_PATH"] = download_path
     # This will determine if the browser will be firefox or chrome.
     os.environ["PUPPETEER_PRODUCT"] = "firefox" if is_firefox else "chrome"
     subprocess.check_call(["node", "node_modules/puppeteer/install.js"])