Raise repo exit errors in place of sys.exit

Bug: b/293344017
Change-Id: I92d81c78eba8ff31b5252415f4c9a515a6c76411
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/381774
Tested-by: Jason Chang <jasonnc@google.com>
Reviewed-by: Joanna Wang <jojwang@google.com>
Commit-Queue: Jason Chang <jasonnc@google.com>

9 files changed, 80 insertions, 34 deletions

diff --git a/command.py b/command.py
index 939a4630..d2129381 100644
--- a/command.py
+++ b/command.py
@@ -16,11 +16,11 @@ import multiprocessing
 import os
 import optparse
 import re
-import sys
 
 from event_log import EventLog
 from error import NoSuchProjectError
 from error import InvalidProjectGroupsError
+from error import RepoExitError
 import progress
 
 
@@ -42,6 +42,10 @@ WORKER_BATCH_SIZE = 32
 DEFAULT_LOCAL_JOBS = min(os.cpu_count(), 8)
 
 
+class UsageError(RepoExitError):
+    """Exception thrown with invalid command usage."""
+
+
 class Command(object):
     """Base class for any command line action in repo."""
 
@@ -215,7 +219,7 @@ class Command(object):
     def Usage(self):
         """Display usage and terminate."""
         self.OptionParser.print_usage()
-        sys.exit(1)
+        raise UsageError()
 
     def CommonValidateOptions(self, opt, args):
         """Validate common options."""
diff --git a/fetch.py b/fetch.py
index 31f8152f..cf8d1d7d 100644
--- a/fetch.py
+++ b/fetch.py
@@ -18,6 +18,11 @@ import subprocess
 import sys
 from urllib.parse import urlparse
 from urllib.request import urlopen
+from error import RepoExitError
+
+
+class FetchFileError(RepoExitError):
+    """Exit error when fetch_file fails."""
 
 
 def fetch_file(url, verbose=False):
@@ -29,6 +34,7 @@ def fetch_file(url, verbose=False):
     scheme = urlparse(url).scheme
     if scheme == "gs":
         cmd = ["gsutil", "cat", url]
+        errors = []
         try:
             result = subprocess.run(
                 cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, check=True
@@ -41,9 +47,10 @@ def fetch_file(url, verbose=False):
                 )
             return result.stdout
         except subprocess.CalledProcessError as e:
+            errors.append(e)
             print(
                 'fatal: error running "gsutil": %s' % e.stderr, file=sys.stderr
             )
-        sys.exit(1)
+        raise FetchFileError(aggregate_errors=errors)
     with urlopen(url) as f:
         return f.read()
diff --git a/git_command.py b/git_command.py
index 588a64fd..36fcfe7c 100644
--- a/git_command.py
+++ b/git_command.py
@@ -19,6 +19,7 @@ import subprocess
 from typing import Any, Optional
 
 from error import GitError
+from error import RepoExitError
 from git_refs import HEAD
 import platform_utils
 from repo_trace import REPO_TRACE, IsTrace, Trace
@@ -44,6 +45,7 @@ DEFAULT_GIT_FAIL_MESSAGE = "git command failure"
 # Common line length limit
 GIT_ERROR_STDOUT_LINES = 1
 GIT_ERROR_STDERR_LINES = 1
+INVALID_GIT_EXIT_CODE = 126
 
 
 class _GitCall(object):
@@ -51,8 +53,9 @@ class _GitCall(object):
     def version_tuple(self):
         ret = Wrapper().ParseGitVersion()
         if ret is None:
-            print("fatal: unable to detect git version", file=sys.stderr)
-            sys.exit(1)
+            msg = "fatal: unable to detect git version"
+            print(msg, file=sys.stderr)
+            raise GitRequireError(msg)
         return ret
 
     def __getattr__(self, name):
@@ -167,10 +170,9 @@ def git_require(min_version, fail=False, msg=""):
         need = ".".join(map(str, min_version))
         if msg:
             msg = " for " + msg
-        print(
-            "fatal: git %s or later required%s" % (need, msg), file=sys.stderr
-        )
-        sys.exit(1)
+        error_msg = "fatal: git %s or later required%s" % (need, msg)
+        print(error_msg, file=sys.stderr)
+        raise GitRequireError(error_msg)
     return False
 
 
@@ -403,6 +405,13 @@ class GitCommand(object):
         )
 
 
+class GitRequireError(RepoExitError):
+    """Error raised when git version is unavailable or invalid."""
+
+    def __init__(self, message, exit_code: int = INVALID_GIT_EXIT_CODE):
+        super().__init__(message, exit_code=exit_code)
+
+
 class GitCommandError(GitError):
     """
     Error raised from a failed git command.
diff --git a/project.py b/project.py
index b268007d..c3eb09c9 100644
--- a/project.py
+++ b/project.py
@@ -2003,8 +2003,8 @@ class Project(object):
             name: The name of the branch to abandon.
 
         Returns:
-            True if the abandon succeeded; False if it didn't; None if the
-            branch didn't exist.
+            True if the abandon succeeded; Raises GitCommandError if it didn't;
+            None if the branch didn't exist.
         """
         rev = R_HEADS + name
         all_refs = self.bare_ref.all
@@ -2025,16 +2025,14 @@ class Project(object):
                 )
             else:
                 self._Checkout(revid, quiet=True)
-
-        return (
-            GitCommand(
-                self,
-                ["branch", "-D", name],
-                capture_stdout=True,
-                capture_stderr=True,
-            ).Wait()
-            == 0
-        )
+        GitCommand(
+            self,
+            ["branch", "-D", name],
+            capture_stdout=True,
+            capture_stderr=True,
+            verify_command=True,
+        ).Wait()
+        return True
 
     def PruneHeads(self):
         """Prune any topic branches already merged into upstream."""
diff --git a/subcmds/abandon.py b/subcmds/abandon.py
index ded287f6..896b348f 100644
--- a/subcmds/abandon.py
+++ b/subcmds/abandon.py
@@ -20,6 +20,11 @@ import sys
 from command import Command, DEFAULT_LOCAL_JOBS
 from git_command import git
 from progress import Progress
+from error import RepoError, RepoExitError
+
+
+class AbandonError(RepoExitError):
+    """Exit error when abandon command fails."""
 
 
 class Abandon(Command):
@@ -68,28 +73,37 @@ It is equivalent to "git branch -D <branchname>".
             branches = nb
 
         ret = {}
+        errors = []
         for name in branches:
-            status = project.AbandonBranch(name)
+            status = None
+            try:
+                status = project.AbandonBranch(name)
+            except RepoError as e:
+                status = False
+                errors.append(e)
             if status is not None:
                 ret[name] = status
-        return (ret, project)
+
+        return (ret, project, errors)
 
     def Execute(self, opt, args):
         nb = args[0].split()
         err = defaultdict(list)
         success = defaultdict(list)
+        aggregate_errors = []
         all_projects = self.GetProjects(
             args[1:], all_manifests=not opt.this_manifest_only
         )
         _RelPath = lambda p: p.RelPath(local=opt.this_manifest_only)
 
         def _ProcessResults(_pool, pm, states):
-            for results, project in states:
+            for results, project, errors in states:
                 for branch, status in results.items():
                     if status:
                         success[branch].append(project)
                     else:
                         err[branch].append(project)
+                aggregate_errors.extend(errors)
                 pm.update(msg="")
 
         self.ExecuteInParallel(
@@ -116,13 +130,13 @@ It is equivalent to "git branch -D <branchname>".
                         " " * len(err_msg) + " | %s" % _RelPath(proj),
                         file=sys.stderr,
                     )
-            sys.exit(1)
+            raise AbandonError(aggregate_errors=aggregate_errors)
         elif not success:
             print(
                 "error: no project has local branch(es) : %s" % nb,
                 file=sys.stderr,
             )
-            sys.exit(1)
+            raise AbandonError(aggregate_errors=aggregate_errors)
         else:
             # Everything below here is displaying status.
             if opt.quiet:
diff --git a/subcmds/init.py b/subcmds/init.py
index 6d7fd857..868d339e 100644
--- a/subcmds/init.py
+++ b/subcmds/init.py
@@ -19,6 +19,8 @@ from color import Coloring
 from command import InteractiveCommand, MirrorSafeCommand
 from git_command import git_require, MIN_GIT_VERSION_SOFT, MIN_GIT_VERSION_HARD
 from wrapper import Wrapper
+from error import UpdateManifestError
+from error import RepoUnhandledExceptionError
 
 _REPO_ALLOW_SHALLOW = os.environ.get("REPO_ALLOW_SHALLOW")
 
@@ -156,7 +158,10 @@ to update the working directory files.
             git_event_log=self.git_event_log,
             manifest_name=opt.manifest_name,
         ):
-            sys.exit(1)
+            manifest_name = opt.manifest_name
+            raise UpdateManifestError(
+                f"Unable to sync manifest {manifest_name}"
+            )
 
     def _Prompt(self, prompt, value):
         print("%-10s [%s]: " % (prompt, value), end="", flush=True)
@@ -346,14 +351,15 @@ to update the working directory files.
                     repo_verify=opt.repo_verify,
                     quiet=opt.quiet,
                 )
-            except wrapper.CloneFailure:
+            except wrapper.CloneFailure as e:
                 err_msg = "fatal: double check your --repo-rev setting."
                 print(
                     err_msg,
                     file=sys.stderr,
                 )
                 self.git_event_log.ErrorEvent(err_msg)
-                sys.exit(1)
+                raise RepoUnhandledExceptionError(e)
+
             branch = rp.GetBranch("default")
             branch.merge = remote_ref
             rp.work_git.reset("--hard", rev)
diff --git a/subcmds/upload.py b/subcmds/upload.py
index 8d949bef..d0c028b9 100644
--- a/subcmds/upload.py
+++ b/subcmds/upload.py
@@ -21,7 +21,7 @@ from typing import List
 
 from command import DEFAULT_LOCAL_JOBS, InteractiveCommand
 from editor import Editor
-from error import UploadError
+from error import UploadError, RepoExitError
 from git_command import GitCommand
 from git_refs import R_HEADS
 from hooks import RepoHook
@@ -31,6 +31,10 @@ from project import ReviewableBranch
 _DEFAULT_UNUSUAL_COMMIT_THRESHOLD = 5
 
 
+class UploadExitError(RepoExitError):
+    """Indicates that there is an upload command error requiring a sys exit."""
+
+
 def _VerifyPendingCommits(branches: List[ReviewableBranch]) -> bool:
     """Perform basic safety checks on the given set of branches.
 
@@ -86,7 +90,7 @@ def _VerifyPendingCommits(branches: List[ReviewableBranch]) -> bool:
 def _die(fmt, *args):
     msg = fmt % args
     print("error: %s" % msg, file=sys.stderr)
-    sys.exit(1)
+    raise UploadExitError(msg)
 
 
 def _SplitEmails(values):
@@ -697,7 +701,7 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
                 )
 
         if have_errors:
-            sys.exit(1)
+            raise branch.error
 
     def _GetMergeBranch(self, project, local_branch=None):
         if local_branch is None:
diff --git a/tests/test_error.py b/tests/test_error.py
index 2733ab8c..2b28f5c2 100644
--- a/tests/test_error.py
+++ b/tests/test_error.py
@@ -21,12 +21,16 @@ import unittest
 import error
 import project
 import git_command
+import fetch
+import command
 from subcmds import all_modules
 
 imports = all_modules + [
     error,
     project,
     git_command,
+    fetch,
+    command,
 ]
 
 
diff --git a/tests/test_git_command.py b/tests/test_git_command.py
index 1e8beabc..3dd31b29 100644
--- a/tests/test_git_command.py
+++ b/tests/test_git_command.py
@@ -204,12 +204,12 @@ class GitRequireTests(unittest.TestCase):
 
     def test_older_fatal(self):
         """Test fatal require calls with old versions."""
-        with self.assertRaises(SystemExit) as e:
+        with self.assertRaises(git_command.GitRequireError) as e:
             git_command.git_require((2,), fail=True)
             self.assertNotEqual(0, e.code)
 
     def test_older_fatal_msg(self):
         """Test fatal require calls with old versions and message."""
-        with self.assertRaises(SystemExit) as e:
+        with self.assertRaises(git_command.GitRequireError) as e:
             git_command.git_require((2,), fail=True, msg="so sad")
             self.assertNotEqual(0, e.code)