shoc-pr-review-runner/scripts/checkout-repositories.sh
Adam Moussa c3cd8f7765
feat: SHOC PR review runner, phase 1
Manually-dispatched GitHub Actions workflow that reviews SHOC pull requests in
a clean environment: exact-head checkout of shoc-frontend-new and shoc-backend,
clean build/test gates, a truthful evidence report, a single-shot Fireworks
review, deterministic output validation, and published artifacts. The runner
never writes to the product repositories or their pull requests.

The review checklists move here from the reviewers' local Cursor commands so
the instructions live outside both product repos.

Phase 1 does not provision a database, start either application, or run live
browser flows; the evidence report records those as NOT_RUN so a review cannot
claim them.

Security architecture: building a PR executes its author's code, so the
workflow is split. The gates job runs that code holding no Fireworks key and
revokes its App token first; the review job holds the key, executes no product
code, and re-checks out this repo fresh. Product checkouts live outside the
workspace, the App token is downscoped at mint time, gate results fail closed
on any duplicate key, changed files are read from git objects rather than the
filesystem, and the validator re-checks every claim against the gate table.
2026-07-29 12:05:38 -04:00

94 lines
3.8 KiB
Bash
Executable file

#!/usr/bin/env bash
# Check out the product repositories at exact SHAs (spec §10).
#
# Repos under review are checked out at their PR head SHA. The companion repo of
# a single-repo review is checked out at its default branch head for contract
# context (spec §10.2) and recorded as such.
#
# Auth: the read-only App installation token is injected ONLY as a host-scoped
# Basic http.extraHeader via GIT_CONFIG_* environment variables for the fetch
# commands. It is never placed in a URL, never Bearer, and never written to
# .git/config, so nothing credential-bearing persists after the run.
#
# Usage: checkout-repositories.sh
# Reads: GH_TOKEN, REVIEW_TYPE, FRONTEND_REPO, BACKEND_REPO,
# FRONTEND_SHA / BACKEND_SHA (empty when that side has no PR),
# COMPANION_BRANCH (default: dev)
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
# shellcheck source=lib.sh
source "$SCRIPT_DIR/lib.sh"
require_env GH_TOKEN REVIEW_TYPE FRONTEND_REPO BACKEND_REPO
COMPANION_BRANCH="${COMPANION_BRANCH:-dev}"
# The Basic-auth header is a derived credential: GitHub masks the raw token it
# minted, but not this transformation of it. Register the mask explicitly so an
# accidental trace or debug flag cannot print a working credential to the log.
AUTH_HEADER_B64="$(printf 'x-access-token:%s' "$GH_TOKEN" | base64 | tr -d '\n')"
if [ -n "${GITHUB_ACTIONS:-}" ]; then
echo "::add-mask::$AUTH_HEADER_B64"
fi
auth_git() {
# git with the Basic auth header injected via env for this invocation only.
GIT_CONFIG_COUNT=1 \
GIT_CONFIG_KEY_0="http.https://github.com/.extraHeader" \
GIT_CONFIG_VALUE_0="Authorization: Basic $AUTH_HEADER_B64" \
GIT_TERMINAL_PROMPT=0 \
git "$@"
}
# fetch_at <dir> <repo> <ref-or-sha> <label>
fetch_at() {
local dir="$1" repo="$2" ref="$3" label="$4"
# Validate before use: the ref reaches git as an argument, so anything other
# than a resolved SHA or the configured companion branch is refused.
if ! [[ "$ref" =~ ^[0-9a-f]{40}$ ]] && [ "$ref" != "$COMPANION_BRANCH" ]; then
die "refusing to fetch unexpected ref '$ref'"
fi
rm -rf "$dir"
mkdir -p "$dir"
git -C "$dir" init -q
git -C "$dir" remote add origin -- "https://github.com/$repo.git"
auth_git -C "$dir" fetch -q --depth=1 origin -- "$ref" || die "fetch of $repo @ $ref failed"
git -C "$dir" checkout -q --detach FETCH_HEAD
local got
got="$(git -C "$dir" rev-parse HEAD)"
if [[ "$ref" =~ ^[0-9a-f]{40}$ ]] && [ "$got" != "$ref" ]; then
die "$repo checkout mismatch: wanted $ref got $got"
fi
log "$label: $repo @ $(git -C "$dir" rev-parse --short=7 HEAD) ($ref)"
}
frontend_dir="$WORKSPACE_DIR/frontend"
backend_dir="$WORKSPACE_DIR/backend"
case "$REVIEW_TYPE" in
frontend)
require_env FRONTEND_SHA
fetch_at "$frontend_dir" "$FRONTEND_REPO" "$FRONTEND_SHA" "frontend (PR head)"
fetch_at "$backend_dir" "$BACKEND_REPO" "$COMPANION_BRANCH" "backend (companion @ $COMPANION_BRANCH)"
;;
backend)
require_env BACKEND_SHA
fetch_at "$backend_dir" "$BACKEND_REPO" "$BACKEND_SHA" "backend (PR head)"
fetch_at "$frontend_dir" "$FRONTEND_REPO" "$COMPANION_BRANCH" "frontend (companion @ $COMPANION_BRANCH)"
;;
paired)
require_env FRONTEND_SHA BACKEND_SHA
fetch_at "$frontend_dir" "$FRONTEND_REPO" "$FRONTEND_SHA" "frontend (PR head)"
fetch_at "$backend_dir" "$BACKEND_REPO" "$BACKEND_SHA" "backend (PR head)"
;;
*) die "invalid REVIEW_TYPE '$REVIEW_TYPE'" ;;
esac
# Record companion context for evidence.
jq -n \
--arg review_type "$REVIEW_TYPE" \
--arg companion_branch "$COMPANION_BRANCH" \
--arg frontend_head "$(git -C "$frontend_dir" rev-parse HEAD)" \
--arg backend_head "$(git -C "$backend_dir" rev-parse HEAD)" \
'{review_type: $review_type, companion_branch: $companion_branch,
frontend_checkout: $frontend_head, backend_checkout: $backend_head}' \
>"$ARTIFACTS_DIR/checkout.json"