qsm-statusline

1// qsm-statusline's function-hooks module.
2import type { On } from "claude-code";
3import { registerNoun } from "./noun.generated.ts";
4
5export function register(on: On): void {
6  // Adds $.statusline: one method per qsm-statusline verb, generated by lib/generate-noun.ts. Never
7  // hand-edit noun.generated.ts or types/index.d.ts.
8  registerNoun(on);
9}
10

1// Generated by lib/generate-noun.ts from qsm.json. Do not hand-edit; run
2// `bun lib/generate-noun.ts plugins/<name>` again after changing qsm.json.
3import type { Caught, EngineInterface, On } from "claude-code";
4import type { Statusline } from "../types/index.d.ts";
5
6/** How one option becomes argv: a positional value (`flag` null), a bare
7 * boolean flag, or a flag and its value; a list repeats it per element. */
8export interface VerbArg {
9  readonly name: string;
10  readonly flag: string | null;
11  readonly boolean?: true;
12}
13
14export interface VerbRow {
15  readonly words: readonly string[];
16  readonly args: readonly VerbArg[];
17  readonly passthrough?: true;
18}
19
20export const verbs: Readonly<Record<string, VerbRow>> = {
21  render: { words: ["qsm-statusline","render"], args: [{ name: "cwd", flag: "--cwd" }, { name: "noColor", flag: "--no-color", boolean: true }] },
22  refresh: { words: ["qsm-statusline","refresh"], args: [{ name: "cwd", flag: "--cwd" }] },
23  doctor: { words: ["qsm-statusline","doctor"], args: [{ name: "settings", flag: "--settings" }] },
24};
25
26/** One verb's argv: its words, each option in declaration order, the
27 * passthrough rest after `--`, and `--json` last. */
28export function argvOf(row: VerbRow, options: Readonly<Record<string, unknown>> = {}): string[] {
29  const argv = [...row.words];
30  for (const arg of row.args) {
31    const value = options[arg.name];
32    const values = Array.isArray(value) ? value : [value];
33    for (const one of values) {
34      if (one === undefined || one === false) {
35        continue;
36      }
37      argv.push(...(arg.flag === null ? [] : [arg.flag]), ...(arg.boolean ? [] : [String(one)]));
38    }
39  }
40  const rest = options.rest;
41  if (row.passthrough && Array.isArray(rest)) {
42    argv.push("--", ...rest.map(String));
43  }
44  argv.push("--json");
45  return argv;
46}
47
48/** The binary prints one outcome envelope on stdout under --json:
49 * { code, exit, reason, message, warnings, data }. Data on ok; otherwise the
50 * code and message become the error. A stale or misbehaving binary that
51 * prints something else (not JSON, or JSON with no numeric `exit`) throws
52 * loud here instead of a raw JSON.parse SyntaxError or a silent `undefined`. */
53export function unwrap(
54  argv: readonly string[],
55  result: { readonly exitCode: number; readonly stdout: string; readonly stderr: string },
56  label = argv.slice(0, 2).join(" "),
57): unknown {
58  const text = result.stdout.trim();
59  const stderr = result.stderr.trim().slice(0, 200);
60  const cause = `(exit ${result.exitCode}): ${stderr.length > 0 ? stderr : "no stderr"}`;
61  if (text.length === 0) {
62    throw new Error(`${argv.join(" ")}: printed no envelope ${cause}`);
63  }
64  let parsed: unknown;
65  try {
66    parsed = JSON.parse(text);
67  } catch {
68    parsed = undefined;
69  }
70  if (typeof parsed !== "object" || parsed === null || typeof (parsed as { exit?: unknown }).exit !== "number") {
71    throw new Error(`${argv.join(" ")}: stdout is not an outcome envelope ${cause}: ${text.slice(0, 200)}`);
72  }
73  const envelope = parsed as { code: string; exit: number; message: string; data: unknown };
74  if (envelope.exit !== 0) {
75    throw new Error(`${label}: ${envelope.code}: ${envelope.message}`);
76  }
77  return envelope.data;
78}
79
80/** What every `.catch` does first: a toast and a log for the person. The toast says `fixedReason`
81 * when the cause may carry something the toast must not show, else the cause; the cause goes to
82 * the log and comes back for the caller's own policy. */
83export function failure(
84  $: EngineInterface,
85  event: string,
86  error: Caught["error"],
87  fixedReason?: string,
88): string {
89  const said = error.message ?? error.kind;
90  $.ui.toast(`qsm-statusline ERROR: ${event}: ${(fixedReason ?? said).slice(0, 120)}`);
91  $.ui.log(`${event} failed (${error.kind}): ${said}`);
92  return said;
93}
94
95/** Adds $.statusline to the engine. Call once from the plugin's own
96 * `register(on, options)` — never call the engine.create hook's own
97 * `next(e)` result from anywhere but here. */
98export function registerNoun(on: On): void {
99  on("engine.create", async (_$, e, next) => {
100    const beneath = await next(e);
101    const run = async (row: VerbRow, options?: Readonly<Record<string, unknown>>): Promise<unknown> => {
102      const argv = argvOf(row, options);
103      let result: Awaited<ReturnType<typeof beneath.process.run>>;
104      try {
105        result = await beneath.process.run(argv);
106      } catch (error) {
107        // A spawn in a deleted directory fails as ENOENT naming the binary; name the directory. A
108        // check that cannot run leaves the spawn's own error as the cause.
109        const gone = await beneath.session
110          .cwd()
111          .then(async (cwd) => ((await beneath.fs.exists(cwd)) ? null : cwd))
112          .catch(() => null);
113        if (gone !== null) {
114          throw new Error(`${row.words.join(" ")}: the session's working directory ${gone} no longer exists; cd to one that does`);
115        }
116        throw error;
117      }
118      return unwrap(argv, result, row.words.join(" "));
119    };
120    const methods = Object.entries(verbs).map(([method, row]) => [
121      method,
122      (options?: Readonly<Record<string, unknown>>) => run(row, options),
123    ]);
124    return { ...beneath, statusline: Object.fromEntries(methods) as Statusline };
125  });
126}
127

1// Generated by lib/generate-noun.ts from qsm.json. Do not hand-edit; run
2// `bun lib/generate-noun.ts plugins/<name>` again after changing qsm.json.
3
4export type Statusline = {
5  render(options: {
6    cwd?: string;
7    noColor?: boolean;
8  }): Promise<unknown>;
9  refresh(options: {
10    cwd?: string;
11  }): Promise<unknown>;
12  doctor(options: {
13    settings?: string;
14  }): Promise<unknown>;
15};
16
17declare module 'claude-code' {
18  interface EngineInterface {
19    statusline: Statusline;
20  }
21}
22