kandev/apps/web/scripts/externalize-strings.mjs

#!/usr/bin/env node
/**
 * Externalize hardcoded user-facing strings to i18next keys.
 *
 * Handles JSX text, display attributes (placeholder/aria-label/title/alt), and
 * toast argument strings. Applies surgical range edits to the ORIGINAL source so
 * diffs stay scoped, emits/merges `src/locales/en/<namespace>.json`, and inserts
 * `const { t } = useTranslation()` (or a module-level `t` import) where needed.
 *
 * SAFETY: a literal is skipped when it is ALSO used as a logic sentinel anywhere
 * in the same file (compared with ==/===/!==/switch-case, or used as an object
 * key / Map key). Translating those silently breaks behavior — see
 * docs/i18n.md ("Do not translate") for the type-to-confirm incident this prevents.
 *
 * Usage: node scripts/externalize-strings.mjs [--write] <dir|file> [...]
 *
 * `DUMP_MODULE_SCOPE=1` lists the module-scope config literals this script
 * declines (see `displayContext`), one per line as `path<TAB>literal`. That is
 * the work-list for the follow-up; see docs/i18n.md ("The guard has blind spots").
 */
import { parseSync } from "@babel/core";
import fs from "node:fs";
import path from "node:path";
import { templateToMessage, templateCall } from "./lib/template-literals.mjs";
import { configureDisplayContext, displayContext } from "./lib/display-context.mjs";

const ROOT = path.resolve(import.meta.dirname, "..");
const EN = path.join(ROOT, "src", "locales", "en");
const WRITE = process.argv.includes("--write");
const TARGETS = process.argv.slice(2).filter((a) => !a.startsWith("--"));
if (!TARGETS.length) {
  console.error("usage: externalize-strings.mjs [--write] <dir|file> [...]");
  process.exit(2);
}

const DISPLAY_ATTRS = new Set(["placeholder", "aria-label", "aria-description", "title", "alt"]);
const TOAST_CALLEES = /^(toast|toast\.(success|error|info|warning|message|loading))$/;
/**
 * Native dialogs whose first argument is copy shown to the user. Guard-blind
 * like toasts: `i18next/no-literal-string` only inspects JSX.
 */
const DIALOG_CALLEES = /^(window\.)?(confirm|alert|prompt)$/;

/**
 * Props on internal components that render their value as copy. Unlike
 * DISPLAY_ATTRS these are not DOM attributes, so they are only display copy by
 * convention — hence an explicit list rather than a pattern. `value`, `href`,
 * `id`, and friends are deliberately absent: those carry data.
 */
const DISPLAY_PROPS = new Set([
  "label",
  "description",
  "tooltip",
  "hint",
  "heading",
  "headline",
  "message",
  "ariaLabel",
  "triggerAriaLabel",
  "addLabel",
  "addAllLabel",
  "applyLabel",
  "submitLabel",
  "actionLabel",
  "secondaryActionLabel",
  "cleanupLabel",
  "emptyLabel",
  "watchLabel",
  "integrationLabel",
  "displayName",
  "validationHint",
  "confirmLabel",
  "cancelLabel",
  "emptyMessage",
  "errorMessage",
  "helpText",
  "subtitle",
  "text",
  "tip",
  "badge",
  "title",
  "labelPrefix",
  "submittingLabel",
  "authErrorBody",
  "errorTitle",
  "backLabel",
  "searchPlaceholder",
  "emptyHint",
  "note",
  "invalidReason",
  "idleLabel",
  "activeLabel",
  "successLabel",
  "failedLabel",
  "disabledReason",
  "externalBlockedReason",
]);

/** Brand/proper nouns and acronyms that must stay untranslated. */
const KEEP_LITERAL =
  /^(Kandev|GitHub|GitLab|Jira|Linear|Slack|Sentry|Azure DevOps|Docker|SSH|ACP|MCP|PR|CI|AI|API|JSON|YAML|LSP|TLS|SQL|URL|ID|PostgreSQL|SQLite|Claude|Codex|OpenCode|Copilot|Amp)$/;

/**
 * Path prefix -> catalog namespace. Ordered: the first matching prefix wins, so
 * more specific paths must come first.
 */
const NAMESPACE_RULES = [
  // Settings -> Executors profile-editor tree. Note the singular
  // `app/settings/executor/`: the plural `app/settings/executors/` is the
  // separate list/create route tree and stays on the `settings` namespace.
  [/^app\/settings\/executor\//, "executors"],
  [
    /^components\/settings\/(profile-edit\/|executor-profile-dialog|executor-profiles-card)/,
    "executors",
  ],
  [/^(app|components)\/settings\//, "settings"],
  [/^app\/office\//, "office"],
  [/^components\/app-sidebar\//, "sidebar"],
  [/^components\/app-status-bar\//, "statusBar"],
  [/^components\/(quick-chat|config-chat)\//, "chat"],
  [/^components\/(kanban\/|kanban-)/, "kanban"],
  [/^components\/(task\/|task-)/, "task"],
  [/^components\/review\//, "review"],
  [/^components\/diff\//, "diff"],
  [/^components\/editors\//, "editors"],
  [/^(app|components)\/github\//, "github"],
  [/^(app|components)\/gitlab\//, "gitlab"],
  [/^(app|components)\/jira\//, "jira"],
  [/^(app|components)\/linear\//, "linear"],
  [/^components\/sentry\//, "sentry"],
  [/^(app|components)\/azure-devops\//, "azureDevops"],
  [/^components\/automations\//, "automations"],
  [/^components\/plugins\//, "plugins"],
  [/^components\/(integrations|vcs)\//, "integrations"],
  [/^app\/stats\//, "stats"],
  [/^app\/auth\//, "auth"],
];

function namespaceFor(rel) {
  const p = rel.replace(/\\/g, "/");
  return NAMESPACE_RULES.find(([re]) => re.test(p))?.[1] ?? "common";
}

function keyFromText(text) {
  const words = text
    .replace(/\{\{[^}]*\}\}/g, " ")
    .replace(/<\/?\d+>/g, " ")
    .replace(/[^A-Za-z0-9 ]+/g, " ")
    .trim()
    .split(/\s+/)
    .filter(Boolean)
    .slice(0, 6);
  if (!words.length) return "text";
  const [first, ...rest] = words;
  return (
    first.toLowerCase() + rest.map((w) => w[0].toUpperCase() + w.slice(1).toLowerCase()).join("")
  );
}

/** Heuristic: is this literal display copy rather than code/data? */
function looksLikeCopy(raw) {
  const s = raw.trim();
  if (s.length < 2) return false;
  if (!/[A-Za-z]/.test(s)) return false;
  if (KEEP_LITERAL.test(s)) return false;
  if (/^https?:\/\//.test(s) || s.startsWith("/") || s.startsWith("~/")) return false; // urls/paths
  if (/^[a-z0-9]+([-_][a-z0-9]+)+$/.test(s)) return false; // kebab/snake identifiers
  if (/^[a-z]+([A-Z][a-z0-9]*)+$/.test(s)) return false; // camelCase identifier
  if (/^[A-Z][A-Z0-9_]*$/.test(s)) return false; // SCREAMING_CASE sentinel
  if (/[{}<>$]/.test(s) && !/\s/.test(s)) return false; // template/code fragment
  if (/^\.?[\w-]+\.(tsx?|jsx?|json|md|ya?ml|css)$/.test(s)) return false; // filenames
  if (/^[\w.-]+@[\w.-]+$/.test(s)) return false; // emails
  if (!/[A-Za-z]{2}/.test(s)) return false;
  return true;
}

function parse(code, filename) {
  return parseSync(code, {
    filename,
    babelrc: false,
    configFile: false,
    sourceType: "module",
    parserOpts: { plugins: ["typescript", "jsx", "topLevelAwait"] },
  });
}

function walk(node, visit, parent = null) {
  if (!node || typeof node.type !== "string") return;
  visit(node, parent);
  for (const key of Object.keys(node)) {
    if (key === "loc" || key.endsWith("Comments")) continue;
    const child = node[key];
    if (Array.isArray(child)) {
      for (const c of child) if (c && typeof c.type === "string") walk(c, visit, node);
    } else if (child && typeof child.type === "string") walk(child, visit, node);
  }
}

/**
 * Every string in this file that participates in logic: comparisons, switch
 * cases, object/member keys, or array-membership checks. These must never be
 * translated.
 */
function sentinelsIn(ast) {
  const out = new Set();
  const add = (n) => {
    if (n?.type === "StringLiteral") out.add(n.value);
  };
  walk(ast, (node) => {
    if (node.type === "BinaryExpression" && /^([=!]==?|in)$/.test(node.operator)) {
      add(node.left);
      add(node.right);
    }
    if (node.type === "SwitchCase") add(node.test);
    if (node.type === "ObjectProperty" && node.computed) add(node.key);
    if (node.type === "MemberExpression" && node.computed) add(node.property);
    // `["a","b"].includes(x)` / `new Set(["a"])` style membership tables
    if (
      node.type === "ArrayExpression" &&
      node.elements.every((e) => e?.type === "StringLiteral")
    ) {
      for (const e of node.elements) add(e);
    }
    // Object keys are frequently enum maps keyed by sentinel.
    if (node.type === "ObjectProperty" && node.key?.type === "StringLiteral") add(node.key);
  });
  return out;
}

/**
 * True when this text node is only part of a sentence — i.e. its parent element
 * also contains expression containers or inline elements. Splitting such a
 * sentence into per-fragment keys bakes in English word order and cannot be
 * translated correctly, so the codemod declines and reports it instead.
 */
/**
 * A short standalone label ("Save", "Add source") is independently translatable
 * even when it sits beside other elements: there is no surrounding prose whose
 * word order could differ per language. Requires an initial capital (a lowercase
 * start signals continuation of a sentence) and no trailing/leading punctuation
 * that implies the sentence carries on.
 */
function isStandaloneLabel(raw) {
  const s = raw.trim();
  if (!/^[A-Z]/.test(s)) return false;
  if (/[,:;]$/.test(s) || /^[,:;.]/.test(s)) return false;
  const words = s.split(/\s+/);
  if (words.length > 3) return false;
  // A trailing period means prose, not a label.
  return !/\.$/.test(s);
}

function isSentenceFragment(node, parent) {
  if (!parent || !Array.isArray(parent.children)) return false;
  const siblings = parent.children.filter((c) => {
    if (c === node) return false;
    if (c.type === "JSXText") return c.value.trim().length > 0;
    if (c.type === "JSXExpressionContainer")
      return (
        c.expression?.type !== "JSXEmptyExpression" &&
        !(c.expression?.type === "StringLiteral" && !c.expression.value.trim())
      );
    return c.type === "JSXElement" || c.type === "JSXFragment";
  });
  return siblings.length > 0;
}

const FUNCTION_TYPES = new Set([
  "FunctionDeclaration",
  "FunctionExpression",
  "ArrowFunctionExpression",
  "ObjectMethod",
  "ClassMethod",
]);
function fnName(node, parent) {
  if (node.id?.name) return node.id.name;
  if (parent?.type === "VariableDeclarator" && parent.id?.type === "Identifier")
    return parent.id.name;
  if (parent?.type === "ObjectProperty" && parent.key?.type === "Identifier")
    return parent.key.name;
  return "";
}
const canUseHooks = (name) => /^[A-Z]/.test(name) || /^use[A-Z]/.test(name);

/**
 * Paths whose strings are NOT display copy, even when they sit in a
 * display-shaped property:
 *  - `lib/api` / `lib/types` are the backend's JSON shape. A translated field
 *    name or default value changes what we send and what gets persisted.
 *  - `lib/state/layout-manager` serializes panel titles into saved layouts, so
 *    a locale change would rewrite stored state.
 *  - test helpers and fixtures are not shipped UI.
 */
const EXCLUDED = [
  /^lib\/api\//,
  /^lib\/types\//,
  /^lib\/state\/layout-manager\//,
  /\.(test-helpers|fixtures|mocks)\.tsx?$/,
];
const isExcluded = (abs) => {
  const rel = path.relative(ROOT, abs).replace(/\\/g, "/");
  return EXCLUDED.some((re) => re.test(rel));
};

// ---------------------------------------------------------------- collect files
function listFiles() {
  const out = [];
  const walkDir = (dir) => {
    for (const e of fs.readdirSync(dir, { withFileTypes: true })) {
      const full = path.join(dir, e.name);
      if (e.isDirectory()) {
        if (["node_modules", "dist", "e2e", "locales", "__tests__"].includes(e.name)) continue;
        walkDir(full);
      } else if (/\.tsx?$/.test(e.name) && !/\.(test|d)\.tsx?$/.test(e.name) && !isExcluded(full)) {
        out.push(full);
      }
    }
  };
  for (const t of TARGETS) {
    const abs = path.isAbsolute(t) ? t : path.join(ROOT, t);
    if (!fs.existsSync(abs)) continue;
    if (fs.statSync(abs).isDirectory()) walkDir(abs);
    else if (/\.tsx?$/.test(abs)) out.push(abs);
  }
  return out;
}

// ------------------------------------------------------------------- catalogs
const catalogs = {};
function loadCatalog(ns) {
  if (catalogs[ns]) return catalogs[ns];
  const file = path.join(EN, `${ns}.json`);
  catalogs[ns] = fs.existsSync(file) ? JSON.parse(fs.readFileSync(file, "utf8")) : {};
  return catalogs[ns];
}
/** Reuse an existing key when the same English text is already in the catalog. */
function keyFor(ns, message) {
  const cat = loadCatalog(ns);
  for (const [k, v] of Object.entries(cat)) if (v === message) return k;
  const common = loadCatalog("common");
  for (const [k, v] of Object.entries(common)) if (v === message) return `common:${k}`;
  const base = keyFromText(message);
  let key = base;
  let n = 2;
  while (key in cat) key = `${base}${n++}`;
  cat[key] = message;
  return key;
}
/** Injected into ./lib/template-literals.mjs, which cannot see this module. */
const DEPS = { walk, looksLikeCopy, keyFor, qualify: (ns, key) => qualify(ns, key) };
const qualify = (ns, key) => (key.includes(":") ? key : `${ns}:${key}`);

// ------------------------------------------------------------------- transform
configureDisplayContext({ DISPLAY_PROPS, DISPLAY_ATTRS, FUNCTION_TYPES });

const report = {
  files: 0,
  jsxText: 0,
  attrs: 0,
  toasts: 0,
  exprLiterals: 0,
  templates: 0,
  skippedTemplate: 0,
  skippedSentinel: 0,
  skippedFragment: 0,
  skippedShadowed: 0,
  skippedInsideTrans: 0,
  skippedModuleScope: 0,
  bindings: 0,
};

/** JSX text child -> {t("ns:key")}, unless it is a sentinel or a fragment. */
function handleJsxText(node, parent, ancestors, { ns, sentinels, edits, noteHost }) {
  if (node.type !== "JSXText") return;
  if (insideTrans(ancestors)) {
    report.skippedInsideTrans += 1;
    return;
  }
  const raw = node.value;
  const trimmed = raw.trim();
  if (!trimmed || !looksLikeCopy(trimmed)) return;
  if (sentinels.has(trimmed)) {
    report.skippedSentinel += 1;
    return;
  }
  if (isSentenceFragment(node, parent) && !isStandaloneLabel(trimmed)) {
    // Part of a sentence interleaved with expressions or inline markup.
    // Externalizing each piece separately would hard-code English word order;
    // these need one <Trans> for the whole sentence, so decline and report.
    report.skippedFragment += 1;
    return;
  }
  const key = qualify(ns, keyFor(ns, trimmed.replace(/\s+/g, " ")));
  const lead = raw.slice(0, raw.indexOf(trimmed));
  const tail = raw.slice(raw.indexOf(trimmed) + trimmed.length);
  edits.push({ start: node.start, end: node.end, text: `${lead}{t("${key}")}${tail}` });
  report.jsxText += 1;
  noteHost();
}

/** placeholder / aria-label / title / alt with a literal value. */
function handleDisplayAttribute(node, { ns, sentinels, edits, noteHost }) {
  if (node.type !== "JSXAttribute" || !DISPLAY_ATTRS.has(String(node.name?.name))) return;
  const v = node.value;
  if (v?.type !== "StringLiteral" || !looksLikeCopy(v.value)) return;
  if (sentinels.has(v.value)) {
    report.skippedSentinel += 1;
    return;
  }
  const key = qualify(ns, keyFor(ns, v.value));
  edits.push({ start: v.start, end: v.end, text: `{t("${key}")}` });
  report.attrs += 1;
  noteHost();
}

/** Every name bound by a function/catch parameter pattern. */
function paramNames(pattern, out = []) {
  if (!pattern || typeof pattern.type !== "string") return out;
  switch (pattern.type) {
    case "Identifier":
      out.push(pattern.name);
      break;
    case "ObjectPattern":
      for (const p of pattern.properties)
        paramNames(p.type === "RestElement" ? p.argument : p.value, out);
      break;
    case "ArrayPattern":
      for (const e of pattern.elements) paramNames(e, out);
      break;
    case "AssignmentPattern":
      paramNames(pattern.left, out);
      break;
    case "RestElement":
      paramNames(pattern.argument, out);
      break;
    default:
      break;
  }
  return out;
}

/**
 * True when `t` names something other than the translate function at this point
 * — almost always a `.map((t) => …)` callback parameter over tasks/terminals.
 * Emitting `t("ns:key")` there calls the item, so the rewrite must be declined.
 */
function tIsShadowed(ancestors) {
  for (const a of ancestors) {
    if (FUNCTION_TYPES.has(a.type)) {
      for (const p of a.params ?? []) if (paramNames(p).includes("t")) return true;
    }
    if (a.type === "CatchClause" && paramNames(a.param).includes("t")) return true;
  }
  return false;
}

/**
 * True when the node sits inside a `<Trans>` element.
 *
 * `<Trans>` children are a FALLBACK rendering whose positions define the `<n>`
 * tag indices in the catalog message. Rewriting a literal in there to `t(...)`
 * inserts a new expression child, shifts every index after it, and silently
 * repoints the message's tags at the wrong elements — the copy then renders as
 * duplicated fragments with empty tags. The whole sentence already belongs to
 * one key, so there is nothing to externalize here.
 */
const insideTrans = (ancestors) =>
  ancestors.some(
    (a) =>
      (a.type === "JSXElement" && a.openingElement?.name?.name === "Trans") ||
      (a.type === "JSXOpeningElement" && a.name?.name === "Trans"),
  );

function handleJsxExpressionLiteral(node, ancestors, { ns, rel, sentinels, edits, noteHost }) {
  if (node.type !== "StringLiteral" || !looksLikeCopy(node.value)) return;
  if (sentinels.has(node.value)) {
    report.skippedSentinel += 1;
    return;
  }
  if (tIsShadowed(ancestors)) {
    // `items.map((t) => …)` rebinds `t` to the item, so emitting `t("ns:key")`
    // here would call the item instead of translating. Decline and report.
    report.skippedShadowed += 1;
    return;
  }
  if (insideTrans(ancestors)) {
    report.skippedInsideTrans += 1;
    return;
  }
  const context = displayContext(node, ancestors);
  if (context === null) return;
  if (context === "module-scope") {
    report.skippedModuleScope += 1;
    if (process.env.DUMP_MODULE_SCOPE) {
      console.error(`MODULE_SCOPE\t${rel}\t${JSON.stringify(node.value)}`);
    }
    return;
  }
  const call = `t("${qualify(ns, keyFor(ns, node.value))}")`;
  // A bare attribute value needs braces; the others are already expressions.
  edits.push({ start: node.start, end: node.end, text: context === "attr" ? `{${call}}` : call });
  report.exprLiterals += 1;
  noteHost();
}

/** A template literal in a display position -> t() with named placeholders. */
function handleTemplateLiteral(node, ancestors, ctx) {
  if (node.type !== "TemplateLiteral" || !node.expressions.length) return;
  if (tIsShadowed(ancestors) || insideTrans(ancestors)) return;
  const context = displayContext(node, ancestors);
  if (context === null || context === "module-scope") return;
  // Only non-empty chunks can be sentinels: a template ending in `${x}` has an
  // empty trailing quasi, and "" is a sentinel in almost every file.
  const chunks = node.quasis.map((q) => (q.value.cooked ?? "").trim()).filter(Boolean);
  if (chunks.some((chunk) => ctx.sentinels.has(chunk))) {
    report.skippedSentinel += 1;
    return;
  }
  emitTemplateArg(node, ctx, context === "attr");
}

/** `toast` / `toast.error` / `window.confirm` as a dotted name, or "". */
function calleeName(callee) {
  if (callee.type === "Identifier") return callee.name;
  if (
    callee.type === "MemberExpression" &&
    callee.object.type === "Identifier" &&
    callee.property.type === "Identifier"
  ) {
    return `${callee.object.name}.${callee.property.name}`;
  }
  return "";
}

/**
 * Convert a template literal to a `t()` call. `braces` wraps the result for a
 * bare JSX attribute value (`aria-label={t(...)}`); call arguments need none.
 */
function emitTemplateArg(node, { ns, source, edits, noteHost }, braces = false) {
  const parts = templateToMessage(node, DEPS);
  if (!parts) {
    report.skippedTemplate += 1;
    return;
  }
  const call = templateCall(node, ns, parts, source, DEPS);
  edits.push({ start: node.start, end: node.end, text: braces ? `{${call}}` : call });
  report.templates += 1;
  noteHost();
}

/** toast("...") / toast.error("...") / confirm("...") first argument. */
function handleToastCall(node, ancestors, ctx) {
  if (node.type !== "CallExpression") return;
  const name = calleeName(node.callee);
  if (!TOAST_CALLEES.test(name) && !DIALOG_CALLEES.test(name)) return;
  // `terminals.map((t) => … confirm(`Destroy ${t.label}?`))` rebinds `t` to the
  // item, so an emitted t("key") would call the item instead of translating.
  if (tIsShadowed(ancestors)) {
    report.skippedShadowed += 1;
    return;
  }
  const { ns, sentinels, edits, noteHost } = ctx;
  const arg = node.arguments[0];
  if (arg?.type === "TemplateLiteral") {
    // `toast.error(`Failed to save: ${msg}`)` — same copy, different node type.
    emitTemplateArg(arg, ctx);
    return;
  }
  if (arg?.type !== "StringLiteral" || !looksLikeCopy(arg.value)) return;
  if (sentinels.has(arg.value)) {
    report.skippedSentinel += 1;
    return;
  }
  const key = qualify(ns, keyFor(ns, arg.value));
  edits.push({ start: arg.start, end: arg.end, text: `t("${key}")` });
  report.toasts += 1;
  noteHost();
}

/** Insert a statement after the last COMPLETE import (multi-line aware). */
function addImport(src, statement) {
  if (src.includes(statement)) return src;
  const lines = src.split("\n");
  let last = -1;
  let open = false;
  for (let i = 0; i < lines.length; i++) {
    const l = lines[i];
    if (open) {
      if (/^\}\s*from/.test(l)) {
        open = false;
        last = i;
      }
      continue;
    }
    if (/^import\s/.test(l)) {
      if (/;\s*$/.test(l)) last = i;
      else open = true;
    }
  }
  if (last === -1) {
    // No imports at all. The statement must still land BELOW any leading
    // "use client"/"use strict" directive — above it, the directive stops being
    // the first statement and degrades into a stray expression.
    let at = 0;
    while (at < lines.length && /^\s*$/.test(lines[at])) at++;
    if (/^\s*["']use (client|strict)["'];?\s*$/.test(lines[at] ?? "")) at++;
    lines.splice(at, 0, statement);
    return lines.join("\n");
  }
  lines.splice(last + 1, 0, statement);
  return lines.join("\n");
}

/** Ensure `useTranslation` and/or the module-level `t` are imported. */
function wireImports(src, { needModuleT, addedBindings }) {
  let out = src;
  if (addedBindings || /\buseTranslation\(/.test(out)) {
    if (!/from "react-i18next"/.test(out)) {
      out = addImport(out, `import { useTranslation } from "react-i18next";`);
    } else if (!/\buseTranslation\b[^}]*\} from "react-i18next"/.test(out)) {
      out = out.replace(
        /import \{([^}]*)\} from "react-i18next";/,
        (m, names) =>
          `import {${names.replace(/\s*$/, "")}, useTranslation } from "react-i18next";`,
      );
    }
  }
  if (needModuleT && !/import \{[^}]*\bt\b[^}]*\} from "@\/lib\/i18n"/.test(out)) {
    out = addImport(out, `import { t } from "@/lib/i18n";`);
  }
  return out;
}

function transform(file) {
  const original = fs.readFileSync(file, "utf8");
  const rel = path.relative(ROOT, file);
  const ns = namespaceFor(rel);
  let ast;
  try {
    ast = parse(original, file);
  } catch {
    return;
  }
  const sentinels = sentinelsIn(ast);
  const edits = [];
  const needT = []; // function nodes that must gain a hook binding
  let needModuleT = false;
  const stack = [];

  const noteHost = () => {
    const host = [...stack].reverse().find((f) => canUseHooks(f.name));
    if (host) {
      if (!needT.includes(host.node)) needT.push(host.node);
    } else {
      needModuleT = true;
    }
  };

  const ctx = { ns, rel, source: original, sentinels, edits, noteHost };
  const ancestors = [];
  const visit = (node, parent) => {
    const isFn = FUNCTION_TYPES.has(node.type);
    if (isFn) stack.push({ node, name: fnName(node, parent) });

    handleJsxText(node, parent, ancestors, ctx);
    handleDisplayAttribute(node, ctx);
    handleToastCall(node, ancestors, ctx);
    handleJsxExpressionLiteral(node, ancestors, ctx);
    handleTemplateLiteral(node, ancestors, ctx);

    ancestors.push(node);
    for (const key of Object.keys(node)) {
      if (key === "loc" || key.endsWith("Comments")) continue;
      const child = node[key];
      if (Array.isArray(child)) {
        for (const c of child) if (c && typeof c.type === "string") visit(c, node);
      } else if (child && typeof child.type === "string") visit(child, node);
    }
    ancestors.pop();
    if (isFn) stack.pop();
  };
  visit(ast, null);

  if (!edits.length) return;

  // Hook bindings are folded into the SAME edit list: applying them separately
  // would use AST offsets already invalidated by the text edits above.
  const alreadyBound = (fn) => {
    let found = false;
    walk(fn.body ?? fn, (n) => {
      if (
        n.type === "VariableDeclarator" &&
        n.init?.type === "CallExpression" &&
        n.init.callee.type === "Identifier" &&
        n.init.callee.name === "useTranslation"
      )
        found = true;
    });
    return found;
  };
  let bindingCount = 0;
  for (const fn of needT) {
    if (alreadyBound(fn)) continue;
    const body = fn.body;
    if (body?.type !== "BlockStatement") continue;
    edits.push({
      start: body.start + 1,
      end: body.start + 1,
      text: `\n  const { t } = useTranslation();`,
    });
    bindingCount += 1;
  }

  // Apply from the end so earlier offsets stay valid; a zero-width insert at the
  // same position as a replacement must land after it, hence the length tiebreak.
  edits.sort((a, b) => b.start - a.start || a.end - a.start - (b.end - b.start));
  let out = original;
  let lastStart = Infinity;
  for (const e of edits) {
    if (e.end > lastStart) continue;
    out = out.slice(0, e.start) + e.text + out.slice(e.end);
    lastStart = e.start;
  }
  report.bindings += bindingCount;

  out = wireImports(out, { needModuleT, addedBindings: bindingCount });

  if (out !== original) {
    report.files += 1;
    if (WRITE) fs.writeFileSync(file, out);
  }
}

listFiles().forEach(transform);

if (WRITE) {
  fs.mkdirSync(EN, { recursive: true });
  for (const [ns, entries] of Object.entries(catalogs)) {
    const sorted = Object.fromEntries(
      Object.entries(entries).sort(([a], [b]) => a.localeCompare(b)),
    );
    // Match the existing catalogs' escaping so the diff stays scoped to real
    // message changes rather than re-encoding every non-ASCII character.
    const json = JSON.stringify(sorted, null, 2).replace(
      /[\u0080-\uffff]/g,
      (ch) => `\\u${ch.charCodeAt(0).toString(16).padStart(4, "0")}`,
    );
    fs.writeFileSync(path.join(EN, `${ns}.json`), json + "\n");
  }
}
console.log(JSON.stringify({ ...report, wrote: WRITE }, null, 2));