T-021: Add multi-execution support to exec command (#125)

* T-021: Add multi-execution support to exec command

- Add --all, --indexes, --until-success, --summary flags to exec command
- Implement JSONL streaming output with run records and summary
- Add comprehensive command selection logic with precedence handling
- Support index ranges (e.g., '0,2-3') and validation
- Maintain backward compatibility with single command execution
- Add 19 comprehensive unit tests covering all new functionality
- Update README.md with detailed multi-execution documentation
- Implement proper error handling and validation for all new features

Resolves #111

* Fix CI issues: mypy command, JSON output, and exit codes

- Fix mypy command in CI workflow to specify autorepro tests paths
- Fix JSON output parsing in exec CLI tests for multi-execution format
- Fix exit code mismatch: return 2 for out-of-range index errors
- Update unit tests to expect correct exit codes
- Prevent duplicate JSONL records in multi-execution mode
- Add noqa comment for PLR0912 complexity warning

Resolves CI test failures for T-021

Author: ali90h

.github/workflows/ci.yml

@@ -52,7 +52,7 @@ jobs:
         run: python -m ruff check .
 
       - name: Mypy (type check)
-        run: mypy || true
+        run: mypy autorepro tests || true
 
       - name: Export PYTHON_BIN
         run: echo "PYTHON_BIN=$(which python)" >> $GITHUB_ENV

README.md

@@ -291,6 +291,69 @@ $ autorepro scan --json --show 3
 - **Python**: `pyproject.toml`, `setup.py`, `requirements.txt`, `*.py`
 - **Rust**: `Cargo.toml`, `Cargo.lock`, `*.rs`
 
+### Exec Command (Multi-execution Support)
+
+Executes commands from a reproduction plan with support for single or multiple command execution, early stopping, and structured logging.
+
+```bash
+# Execute single command (default behavior)
+$ autorepro exec --desc "pytest failing"
+# Executes the top-ranked command
+
+# Execute all candidate commands in order
+$ autorepro exec --desc "pytest failing" --all
+# Runs all suggested commands sequentially
+
+# Execute specific commands by index
+$ autorepro exec --desc "test issues" --indexes "0,2-4"
+# Runs commands at indices 0, 2, 3, and 4
+
+# Stop at first successful command
+$ autorepro exec --desc "build problems" --until-success
+# Stops execution after first command with exit code 0
+
+# Multi-execution with JSONL logging
+$ autorepro exec --desc "CI tests" --all --jsonl runs.jsonl --summary summary.json
+
+# Dry-run to preview selected commands
+$ autorepro exec --desc "npm test" --indexes "1,3" --dry-run
+[1] npm test --verbose
+[3] npm run test:unit
+```
+
+**Multi-execution Features:**
+
+- **`--all`**: Execute all candidate commands in their original order
+- **`--indexes "N,M-P"`**: Execute specific commands by indices/ranges (comma-separated)
+- **`--until-success`**: Stop after the first command that exits with code 0
+- **`--summary FILE.json`**: Write final execution summary to JSON file
+- **Command precedence**: `--indexes` takes precedence over `--all`, both override single `--index`
+
+**JSONL Output Format:**
+
+When using `--jsonl`, each execution produces a run record followed by a final summary:
+
+```jsonl
+{"type": "run", "index": 0, "cmd": "pytest", "start_ts": "2025-09-13T12:00:00Z", "end_ts": "2025-09-13T12:00:05Z", "exit_code": 1, "duration_ms": 5000}
+{"type": "run", "index": 1, "cmd": "pytest -v", "start_ts": "2025-09-13T12:00:05Z", "end_ts": "2025-09-13T12:00:08Z", "exit_code": 0, "duration_ms": 3000}
+{"type": "summary", "schema_version": 1, "tool": "autorepro", "runs": 2, "successes": 1, "first_success_index": 1}
+```
+
+**Execution Options:**
+
+- `--timeout N`: Command timeout in seconds (default: 120)
+- `--env KEY=VAL`: Set environment variable (repeatable)
+- `--env-file PATH`: Load environment variables from file
+- `--tee PATH`: Append full stdout/stderr to log file
+- `--jsonl PATH`: Stream JSONL records for each run and summary
+- `--dry-run`: Print selected commands without executing
+
+**Exit Behavior:**
+
+- **Single execution**: Returns the command's exit code
+- **Multi-execution**: Returns 0 if any command succeeded, otherwise the last exit code
+- **`--until-success`**: Returns 0 when a command succeeds, otherwise the last failure code
+
 ### Init Command
 
 Creates a devcontainer.json file with default configuration (Python 3.11, Node 20, Go 1.22). The command is idempotent and provides atomic file writes.