tests: Add `test-js-with-puppeteer` similar to `test-js-with-casper`.

Note that there are no puppeteer tests yet; this is just preparatory
infrastructure.

tools/test-js-with-puppeteer

@@ -0,0 +1,102 @@
+#!/usr/bin/env python3
+import argparse
+import subprocess
+import sys
+import os
+import glob
+import shlex
+
+ZULIP_PATH = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+
+os.environ["PUPPETEER_TESTS"] = "1"
+os.environ["CHROMIUM_EXECUTABLE"] = os.path.join(ZULIP_PATH, "node_modules/.bin/chromium")
+os.environ.pop("http_proxy", "")
+os.environ.pop("https_proxy", "")
+
+usage = """test-js-with-puppeteer [options]
+    test-js-with-puppeteer # Run all test files
+    test-js-with-puppeteer 09-navigation.js # Run a single test file
+    test-js-with-puppeteer 09 # Run a single test file 09-navigation.js
+    test-js-with-puppeteer 01-login.js 03-narrow.js # Run a few test files
+    test-js-with-puppeteer 01 03 # Run a few test files, 01-login.js and 03-narrow.js here"""
+parser = argparse.ArgumentParser(usage)
+
+parser.add_argument('--interactive', dest='interactive',
+                    action="store_true",
+                    default=False, help='Run tests interactively')
+parser.add_argument('--force', dest='force',
+                    action="store_true",
+                    default=False, help='Run tests despite possible problems.')
+parser.add_argument('tests', nargs=argparse.REMAINDER,
+                    help='Specific tests to run; by default, runs all tests')
+
+options = parser.parse_args()
+
+sys.path.insert(0, ZULIP_PATH)
+
+# check for the venv
+from tools.lib import sanity_check
+sanity_check.check_venv(__file__)
+
+from tools.lib.test_script import assert_provisioning_status_ok
+from tools.lib.test_server import test_server_running
+
+from typing import Iterable
+
+assert_provisioning_status_ok(options.force)
+
+os.chdir(ZULIP_PATH)
+
+subprocess.check_call(['node', 'node_modules/puppeteer/install.js'])
+
+os.makedirs('var/puppeteer', exist_ok=True)
+
+for f in glob.glob('var/puppeteer/puppeteer-failure*.png'):
+    os.remove(f)
+
+def run_tests(files: Iterable[str], external_host: str) -> None:
+    test_dir = os.path.join(ZULIP_PATH, 'frontend_tests/puppeteer_tests')
+    test_files = []
+    for file in files:
+        for file_name in os.listdir(test_dir):
+            if file_name.startswith(file):
+                file = file_name
+                break
+        if not os.path.exists(file):
+            file = os.path.join(test_dir, file)
+        test_files.append(os.path.abspath(file))
+
+    if not test_files:
+        test_files = sorted(glob.glob(os.path.join(test_dir, '*.js')))
+
+    def run_tests() -> int:
+        ret = 1
+        for test_file in test_files:
+            test_name = os.path.basename(test_file)
+            cmd = ["node"] + [test_file]
+            print("\n\n===================== %s\nRunning %s\n\n" % (test_name, " ".join(map(shlex.quote, cmd))), flush=True)
+            ret = subprocess.call(cmd)
+            if ret != 0:
+                return ret
+        return 0
+
+    with test_server_running(False, external_host):
+        # Important: do this next call inside the `with` block, when Django
+        #            will be pointing at the test database.
+        subprocess.check_call('tools/setup/generate-test-credentials')
+        if options.interactive:
+            response = input('Press Enter to run tests, "q" to quit: ')
+            ret = 1
+            while response != 'q':
+                ret = run_tests()
+                if ret != 0:
+                    response = input('Tests failed. Press Enter to re-run tests, "q" to quit: ')
+        else:
+            ret = 1
+            ret = run_tests()
+    if ret != 0:
+        sys.exit(ret)
+
+external_host = "zulipdev.com:9981"
+run_tests(options.tests, external_host)
+sys.exit(0)