Add support for test tmpdir to fuchsia test runner

Also format the script to keep the code nice.

Author: djkoloski

src/ci/docker/scripts/fuchsia-test-runner.py

@@ -171,7 +171,6 @@ def ffx_isolate_dir(self):
  def home_dir(self):
  return os.path.join(self.tmp_dir(), "user-home")
 
-
  def start_ffx_isolation(self):
  # Most of this is translated directly from ffx's isolate library
  os.mkdir(self.ffx_isolate_dir())
@@ -424,7 +423,7 @@ def start(self):
  )
 
  # Create lockfiles
- open(self.pm_lockfile_path(), 'a').close()
+ open(self.pm_lockfile_path(), "a").close()
 
  # Write to file
  self.write_to_file()
@@ -458,6 +457,7 @@ def start(self):
  ],
  use: [
  {{ storage: "data", path: "/data" }},
+ {{ storage: "tmp", path: "/tmp" }},
  {{ protocol: [ "fuchsia.process.Launcher" ] }},
  {{ protocol: [ "fuchsia.posix.socket.Provider" ] }}
  ],
@@ -571,6 +571,9 @@ def log(msg):
  if os.getenv("RUST_BACKTRACE") == None:
  env_vars += f'\n "RUST_BACKTRACE=0",'
 
+ # Use /tmp as the test temporary directory
+ env_vars += f'\n "RUST_TEST_TMPDIR=/tmp",'
+
  cml.write(
  self.CML_TEMPLATE.format(env_vars=env_vars, exe_name=exe_name)
  )
@@ -642,7 +645,7 @@ def log(msg):
  log("Publishing package to repo...")
 
  # Publish package to repo
- with open(self.pm_lockfile_path(), 'w') as pm_lockfile:
+ with open(self.pm_lockfile_path(), "w") as pm_lockfile:
  fcntl.lockf(pm_lockfile.fileno(), fcntl.LOCK_EX)
  subprocess.check_call(
  [
@@ -1045,9 +1048,7 @@ def print_help(args):
  )
  debug_parser.set_defaults(func=debug)
 
- syslog_parser = subparsers.add_parser(
- "syslog", help="prints the device syslog"
- )
+ syslog_parser = subparsers.add_parser("syslog", help="prints the device syslog")
  syslog_parser.set_defaults(func=syslog)
 
  args = parser.parse_args()