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`install-hook.ts`

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install-hook.tsBlame182 lines · 1 contributor

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9018b1fClaude	1	/**
	2	* `gluecron hook install commit-msg` / `gluecron hook uninstall commit-msg`
	3	*
	4	* Installs a `.git/hooks/prepare-commit-msg` script that calls
	5	* `gluecron ai commit-msg` and writes the AI-drafted message into the
	6	* commit-message file — but only when the file is empty (so explicit
	7	* `-m` and amends are untouched).
	8	*
	9	* Idempotent: re-running `install` overwrites the file; `uninstall`
	10	* only removes a file that carries our marker (so a hand-written hook
	11	* is never clobbered).
	12	*/
	13
	14	import {
	15	existsSync,
	16	readFileSync,
	17	writeFileSync,
	18	chmodSync,
	19	unlinkSync,
	20	mkdirSync,
	21	} from "node:fs";
	22	import { spawnSync } from "node:child_process";
	23	import { join } from "node:path";
	24
	25	export const HOOK_MARKER = "# gluecron-prepare-commit-msg-hook";
	26
	27	/**
	28	* Body of the hook script. Kept in a separate function so the test
	29	* suite can assert on the contents without touching the filesystem.
	30	*
	31	* $1 — path to the message file
	32	* $2 — source ("message" \| "template" \| "commit" \| "merge" \| "squash" \| "")
	33	* $3 — sha (when amending)
	34	*
	35	* We only fire when $2 is empty (a vanilla `git commit` with no -m).
	36	* Otherwise we leave the message untouched so amends, merges, and
	37	* `-m "..."` keep their existing behaviour.
	38	*/
	39	export function hookScript(binPath: string): string {
	40	return `#!/usr/bin/env bash
	41	${HOOK_MARKER}
	42	#
	43	# Installed by \`gluecron hook install commit-msg\`. Calls the gluecron CLI
	44	# to draft a commit message when none was supplied.
	45
	46	set -e
	47
	48	COMMIT_MSG_FILE="$1"
	49	COMMIT_SOURCE="$2"
	50
	51	# Only act on a plain \`git commit\` (no -m, no template, no amend).
	52	if [ -n "$COMMIT_SOURCE" ]; then
	53	exit 0
	54	fi
	55
	56	# Bail if the user already typed something.
	57	if [ -s "$COMMIT_MSG_FILE" ]; then
	58	existing=$(grep -v '^#' "$COMMIT_MSG_FILE" \| tr -d '[:space:]' \|\| true)
	59	if [ -n "$existing" ]; then
	60	exit 0
	61	fi
	62	fi
	63
	64	DRAFT=$(${binPath} ai commit-msg 2>/dev/null \|\| true)
	65	if [ -n "$DRAFT" ]; then
	66	# Preserve any trailing comment lines (status summary git appends).
	67	TRAILER=$(grep '^#' "$COMMIT_MSG_FILE" \|\| true)
	68	{
	69	printf '%s\\n' "$DRAFT"
	70	if [ -n "$TRAILER" ]; then
	71	printf '\\n'
	72	printf '%s\\n' "$TRAILER"
	73	fi
	74	} > "$COMMIT_MSG_FILE"
	75	fi
	76
	77	exit 0
	78	`;
	79	}
	80
	81	export function findGitDir(cwd: string = process.cwd()): string \| null {
	82	const r = spawnSync("git", ["rev-parse", "--git-dir"], {
	83	cwd,
	84	encoding: "utf8",
	85	});
	86	if (r.status !== 0) return null;
	87	const dir = (r.stdout \|\| "").trim();
	88	if (!dir) return null;
	89	return dir.startsWith("/") ? dir : join(cwd, dir);
	90	}
	91
	92	export interface HookDeps {
	93	out: (msg: string) => void;
	94	cwd?: string;
	95	/** Override the path used inside the generated hook script (defaults to "gluecron"). */
	96	binPath?: string;
	97	/** Override findGitDir for tests. */
	98	findGitDirImpl?: typeof findGitDir;
	99	}
	100
	101	export async function runHookInstall(
	102	argv: string[],
	103	deps: HookDeps
	104	): Promise<number> {
	105	const target = argv[0];
	106	if (target !== "commit-msg") {
	107	deps.out("usage: gluecron hook install commit-msg");
	108	return 1;
	109	}
	110	const gitDir = (deps.findGitDirImpl ?? findGitDir)(deps.cwd);
	111	if (!gitDir) {
	112	deps.out("error: not a git repository (run from inside a git checkout)");
	113	return 1;
	114	}
	115	const hooksDir = join(gitDir, "hooks");
	116	mkdirSync(hooksDir, { recursive: true });
	117	const hookPath = join(hooksDir, "prepare-commit-msg");
	118
	119	// Refuse to clobber a hand-written hook unless it carries our marker.
	120	if (existsSync(hookPath)) {
	121	const existing = readFileSync(hookPath, "utf8");
	122	if (!existing.includes(HOOK_MARKER)) {
	123	deps.out(
	124	`error: ${hookPath} already exists and was not installed by gluecron. ` +
	125	"Remove it manually if you want gluecron to manage it."
	126	);
	127	return 1;
	128	}
	129	}
	130
	131	const bin = deps.binPath \|\| "gluecron";
	132	writeFileSync(hookPath, hookScript(bin), "utf8");
	133	chmodSync(hookPath, 0o755);
	134	deps.out(`installed ${hookPath}`);
	135	deps.out(
	136	"next commit with an empty message will auto-fill from the AI draft."
	137	);
	138	return 0;
	139	}
	140
	141	export async function runHookUninstall(
	142	argv: string[],
	143	deps: HookDeps
	144	): Promise<number> {
	145	const target = argv[0];
	146	if (target !== "commit-msg") {
	147	deps.out("usage: gluecron hook uninstall commit-msg");
	148	return 1;
	149	}
	150	const gitDir = (deps.findGitDirImpl ?? findGitDir)(deps.cwd);
	151	if (!gitDir) {
	152	deps.out("error: not a git repository");
	153	return 1;
	154	}
	155	const hookPath = join(gitDir, "hooks", "prepare-commit-msg");
	156	if (!existsSync(hookPath)) {
	157	deps.out("nothing to uninstall.");
	158	return 0;
	159	}
	160	const existing = readFileSync(hookPath, "utf8");
	161	if (!existing.includes(HOOK_MARKER)) {
	162	deps.out(
	163	`error: ${hookPath} exists but was not installed by gluecron — refusing to remove.`
	164	);
	165	return 1;
	166	}
	167	unlinkSync(hookPath);
	168	deps.out(`removed ${hookPath}`);
	169	return 0;
	170	}
	171
	172	export async function runHook(
	173	argv: string[],
	174	deps: HookDeps
	175	): Promise<number> {
	176	const sub = argv[0];
	177	const rest = argv.slice(1);
	178	if (sub === "install") return runHookInstall(rest, deps);
	179	if (sub === "uninstall") return runHookUninstall(rest, deps);
	180	deps.out("usage: gluecron hook (install\|uninstall) commit-msg");
	181	return 1;
	182	}