Replace review.sh with run_agent.py and extract review prompt template

scripts/review.md

@@ -0,0 +1,59 @@
+You are a code reviewer for a draft-managed change about to be committed.
+
+Branch: {DRAFT_BRANCH}
+Base branch: {DRAFT_BASE_BRANCH}
+
+Run `git diff {DRAFT_BASE_BRANCH}...HEAD` in the repository at `{DRAFT_REPO_DIR}` to get the diff.
+Read the spec from `{DRAFT_SPEC_FILE}`.
+
+## Review rules
+
+- The spec is the source of truth.
+- Flag errors or bugs related to the changed files (anything wrong inside the diff).
+- Flag mismatches between the diff and the spec (the spec asks for X, the diff does Y).
+- Do NOT flag nice-to-have features. If the spec doesn't ask for it, don't suggest adding it.
+- Do NOT flag refactoring opportunities. If the existing code is not buggy, leave it alone, even if it could be cleaner.
+- Do NOT flag stylistic preferences without a correctness impact.
+- Report at most 3 items. If more real issues exist, pick the most severe (severity = potential to cause incorrect runtime behaviour or spec violation) and drop the rest.
+
+## Output
+
+There are exactly two valid outputs. Choose one. Never both. Never something else.
+
+(a) If no issues meet the criteria above, output nothing at all (empty output).
+
+(b) Otherwise, output up to 3 items in the format below. No preamble. Items separated by a blank line.
+
+## <name (1-4 words)>
+
+**Summary**: <one to three sentences>
+
+**Details**:
+<free-form, as long as needed: file/line references, code excerpts, spec excerpts, failure scenarios>
+
+**Proposed fix**:
+<free-form, as long as needed: concrete change recommendation>
+
+Example of a single well-formed item:
+
+## Missing null check
+
+**Summary**: `parse_config` dereferences the result of `os.environ.get("DRAFT_SPEC_FILE")` without checking for None, which crashes the step when the env var is unset.
+
+**Details**:
+At `src/draft/steps/review_implementation/__init__.py:42`, the diff introduces:
+
+    spec_path = os.environ.get("DRAFT_SPEC_FILE")
+    with open(spec_path) as f:
+        ...
+
+The spec says `DRAFT_SPEC_FILE` is always set, but `open(None)` raises `TypeError`, which surfaces as an opaque crash.
+
+**Proposed fix**:
+Guard the lookup:
+
+    spec_path = os.environ.get("DRAFT_SPEC_FILE")
+    if not spec_path:
+        raise StepError("review-implementation", "DRAFT_SPEC_FILE is required")
+    with open(spec_path) as f:
+        ...

scripts/run_agent.py

@@ -0,0 +1,130 @@
+#!/usr/bin/env python3
+"""Runs a prompt template against auggie.
+
+Usage: run_agent.py <template> <model>
+
+<template> is a path to a prompt template file — absolute or relative to
+DRAFT_REPO_DIR. The template may contain these placeholders which are
+substituted from the corresponding environment variables:
+  {DRAFT_REPO_DIR}  {DRAFT_BRANCH}  {DRAFT_BASE_BRANCH}  {DRAFT_SPEC_FILE}
+
+<model> is forwarded to auggie (e.g. gpt-4.1).
+
+Verdict contract: stdout empty → approval; stdout non-empty → rejection;
+rc != 0 → infra failure.
+"""
+
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+from pathlib import Path
+
+TEMPLATE_VARS = ("DRAFT_REPO_DIR", "DRAFT_BRANCH", "DRAFT_BASE_BRANCH", "DRAFT_SPEC_FILE")
+
+
+def die(msg: str) -> None:
+    print(f"run_agent.py: {msg}", file=sys.stderr)
+    sys.exit(1)
+
+
+def resolve_template_path(template: str, repo_dir: str) -> Path:
+    p = Path(template)
+    return p if p.is_absolute() else Path(repo_dir) / p
+
+
+def fill_template(text: str, env: dict[str, str]) -> str:
+    for var in TEMPLATE_VARS:
+        text = text.replace(f"{{{var}}}", env.get(var, ""))
+    return text
+
+
+def check_auggie_auth() -> None:
+    if not shutil.which("auggie"):
+        die("auggie not found on PATH")
+    result = subprocess.run(
+        ["auggie", "token", "print"], capture_output=True, text=True
+    )
+    out = result.stdout + result.stderr
+    if result.returncode != 0 or "SESSION=" not in out:
+        print(
+            "run_agent.py: auggie pre-flight auth check failed;"
+            " run 'auggie login' or export AUGMENT_SESSION_AUTH",
+            file=sys.stderr,
+        )
+        if out.strip():
+            print("--- auggie token print output ---", file=sys.stderr)
+            print(out, file=sys.stderr)
+        sys.exit(1)
+
+
+def run_auggie(prompt: str, model: str, workspace_root: str) -> str:
+    with tempfile.NamedTemporaryFile(mode="w", suffix=".txt", delete=False) as f:
+        f.write(prompt)
+        prompt_file = f.name
+    try:
+        result = subprocess.run(
+            [
+                "auggie",
+                "--print",
+                "--quiet",
+                "--ask",
+                "--workspace-root",
+                workspace_root,
+                "--allow-indexing",
+                "--max-turns",
+                "10",
+                "--model",
+                model,
+                "--instruction-file",
+                prompt_file,
+            ],
+            stdout=subprocess.PIPE,
+            text=True,
+        )
+    finally:
+        os.unlink(prompt_file)
+
+    if result.returncode != 0:
+        print(
+            f"run_agent.py: auggie call failed with rc={result.returncode}",
+            file=sys.stderr,
+        )
+        sys.exit(result.returncode)
+
+    return result.stdout
+
+
+def main() -> None:
+    if len(sys.argv) != 3:
+        die("usage: run_agent.py <template> <model>")
+
+    template_arg, model = sys.argv[1], sys.argv[2]
+
+    repo_dir = os.environ.get("DRAFT_REPO_DIR", "")
+    if not repo_dir:
+        die("DRAFT_REPO_DIR is unset or empty")
+
+    env: dict[str, str] = {var: os.environ.get(var, "") for var in TEMPLATE_VARS}
+
+    template_path = resolve_template_path(template_arg, env["DRAFT_REPO_DIR"])
+    if not template_path.is_file():
+        die(f"template not found: {template_path}")
+
+    template_text = template_path.read_text()
+    if not template_text.strip():
+        die(f"template is empty: {template_path}")
+
+    prompt = fill_template(template_text, env)
+
+    check_auggie_auth()
+
+    stdout = run_auggie(prompt, model, env["DRAFT_REPO_DIR"])
+
+    if stdout.strip():
+        print(stdout, end="")
+
+
+if __name__ == "__main__":
+    main()