refactor: break up git.py::run() into helpers (#538)

src/infrastructure/hands/git.py

@@ -71,6 +71,50 @@ class GitHand:
                 return True
         return False
 
+    async def _exec_subprocess(
+        self, args: str, timeout: int,
+    ) -> tuple[bytes, bytes, int]:
+        """Run git as a subprocess, return (stdout, stderr, returncode).
+
+        Raises TimeoutError if the process exceeds *timeout* seconds.
+        """
+        proc = await asyncio.create_subprocess_exec(
+            "git",
+            *args.split(),
+            stdout=asyncio.subprocess.PIPE,
+            stderr=asyncio.subprocess.PIPE,
+            cwd=self._repo_dir,
+        )
+        try:
+            stdout, stderr = await asyncio.wait_for(
+                proc.communicate(), timeout=timeout,
+            )
+        except TimeoutError:
+            proc.kill()
+            await proc.wait()
+            raise
+        return stdout, stderr, proc.returncode or 0
+
+    @staticmethod
+    def _parse_output(
+        command: str,
+        stdout_bytes: bytes,
+        stderr_bytes: bytes,
+        returncode: int | None,
+        latency_ms: float,
+    ) -> GitResult:
+        """Decode subprocess output into a GitResult."""
+        exit_code = returncode or 0
+        stdout = stdout_bytes.decode("utf-8", errors="replace").strip()
+        stderr = stderr_bytes.decode("utf-8", errors="replace").strip()
+        return GitResult(
+            operation=command,
+            success=exit_code == 0,
+            output=stdout,
+            error=stderr if exit_code != 0 else "",
+            latency_ms=latency_ms,
+        )
+
     async def run(
         self,
         args: str,
@@ -88,14 +132,15 @@ class GitHand:
             GitResult with output or error details.
         """
         start = time.time()
+        command = f"git {args}"
 
         # Gate destructive operations
         if self._is_destructive(args) and not allow_destructive:
             return GitResult(
-                operation=f"git {args}",
+                operation=command,
                 success=False,
                 error=(
-                    f"Destructive operation blocked: 'git {args}'. "
+                    f"Destructive operation blocked: '{command}'. "
                     "Set allow_destructive=True to override."
                 ),
                 requires_confirmation=True,
@@ -103,46 +148,20 @@ class GitHand:
             )
 
         effective_timeout = timeout or self._timeout
-        command = f"git {args}"
 
         try:
-            proc = await asyncio.create_subprocess_exec(
-                "git",
-                *args.split(),
-                stdout=asyncio.subprocess.PIPE,
-                stderr=asyncio.subprocess.PIPE,
-                cwd=self._repo_dir,
+            stdout_bytes, stderr_bytes, returncode = await self._exec_subprocess(
+                args, effective_timeout,
             )
-
-            try:
-                stdout_bytes, stderr_bytes = await asyncio.wait_for(
-                    proc.communicate(), timeout=effective_timeout
-                )
-            except TimeoutError:
-                proc.kill()
-                await proc.wait()
-                latency = (time.time() - start) * 1000
-                logger.warning("Git command timed out after %ds: %s", effective_timeout, command)
-                return GitResult(
-                    operation=command,
-                    success=False,
-                    error=f"Command timed out after {effective_timeout}s",
-                    latency_ms=latency,
-                )
-
+        except TimeoutError:
             latency = (time.time() - start) * 1000
-            exit_code = proc.returncode or 0
-            stdout = stdout_bytes.decode("utf-8", errors="replace").strip()
-            stderr = stderr_bytes.decode("utf-8", errors="replace").strip()
-
+            logger.warning("Git command timed out after %ds: %s", effective_timeout, command)
             return GitResult(
                 operation=command,
-                success=exit_code == 0,
-                output=stdout,
-                error=stderr if exit_code != 0 else "",
+                success=False,
+                error=f"Command timed out after {effective_timeout}s",
                 latency_ms=latency,
             )
-
         except FileNotFoundError:
             latency = (time.time() - start) * 1000
             logger.warning("git binary not found")
@@ -162,6 +181,12 @@ class GitHand:
                 latency_ms=latency,
             )
 
+        return self._parse_output(
+            command, stdout_bytes, stderr_bytes,
+            returncode=returncode,
+            latency_ms=(time.time() - start) * 1000,
+        )
+
     # ── Convenience wrappers ─────────────────────────────────────────────────
 
     async def status(self) -> GitResult: