upgrade to TypeScript 6

.changeset/bundle-source-cache-load-types.md

@@ -0,0 +1,10 @@
+---
+'@endo/bundle-source': minor
+---
+
+`BundleCache.load()` now has a conditional return type based on the `format` option:
+- Omitted (default) → `Promise<BundleSourceResult<'endoZipBase64'>>`
+- Specific format literal → `Promise<BundleSourceResult<format>>`
+- Runtime-typed `ModuleFormat` → `Promise<BundleSourceResult<ModuleFormat>>`
+
+Previously `load()` returned `Promise<unknown>`, requiring callers to assert the bundle shape.

.changeset/daemon-ts6-type-precision.md

@@ -0,0 +1,12 @@
+---
+'@endo/daemon': patch
+---
+
+TypeScript 6 conformance: public types in `types.d.ts` are now more precise.
+
+- `Context.thisDiesIfThatDies` and `thatDiesIfThisDies` parameters tightened from `string` to `FormulaIdentifier` (a branded string type).
+- `RemoteControl` and `RemoteControlState` interface parameters updated from `Promise<EndoGateway>` to `ERef<EndoGateway>` and `cancelled` widened from `Promise<never>` to `Promise<unknown>`.
+- `EndoInspector` generic type parameter renamed from `Record` to `RecordT` to avoid shadowing the built-in `Record` utility type.
+- `SerialJobs.enqueue` parameter widened from `() => Promise<T>` to `() => T | Promise<T>`, matching the runtime behavior (the implementation already awaits the result, so sync callbacks were always supported).
+
+TypeScript consumers implementing or calling these interfaces may need to update their types accordingly.

.gitignore

@@ -19,6 +19,8 @@ coverage
 
 # LLM tools
 .claude/*.local.*
+# UNTIL https://github.com/anthropics/claude-code/issues/27282
+.claude/worktrees/
 
 # Platform metadata
 .DS_Store

.yarnrc.yml

@@ -9,7 +9,7 @@ catalogs:
     eslint-plugin-eslint-comments: ^3.2.0
     eslint-plugin-import: ^2.31.0
     tsd: ^0.32.0
-    typescript: ~5.9.2
+    typescript: ~6.0.2
 
 enableScripts: false
 

package.json

@@ -38,7 +38,7 @@
     "type-coverage": "^2.29.1",
     "typedoc": "^0.28.17",
     "typedoc-plugin-mermaid": "^1.12.0",
-    "typescript": "~5.9.2",
+    "typescript": "catalog:dev",
     "typescript-eslint": "8.39.1",
     "yaml": "^2.8.1",
     "zx": "^8.1.8"

packages/base64/package.json

@@ -47,7 +47,7 @@
     "c8": "catalog:dev",
     "eslint": "catalog:dev",
     "prettier": "^3.5.3",
-    "typescript": "~5.9.2"
+    "typescript": "catalog:dev"
   },
   "files": [
     "./*.d.ts",

packages/benchmark/package.json

@@ -47,7 +47,7 @@
     "esvu": "^1.2.16",
     "rollup": "^4.34.6",
     "tsd": "catalog:dev",
-    "typescript": "~5.9.2"
+    "typescript": "catalog:dev"
   },
   "files": [
     "./*.d.ts",

packages/benchmark/src/benchmark.js

@@ -32,7 +32,7 @@ async function test(name, fn) {
     await fn({ assert, truthy });
     console.log(`✅ Passed`);
   } catch (err) {
-    console.log(`❌ Failed: ${err.message}`);
+    console.log(`❌ Failed: ${/** @type {Error} */ (err).message}`);
   }
 }
 

packages/bundle-source/cache.js

@@ -105,17 +105,20 @@ export const makeBundleCache = (wr, cwd, readPowers, opts) => {
 
     const bundle = await bundleSource(
       rootPath,
-      {
+      /** @type {import('./src/types.js').BundleOptions<ModuleFormat>} */ ({
         ...bundleOptions,
         noTransforms,
         elideComments,
         format,
         conditions: sortedConditions,
-      },
-      {
+      }),
+      /** @type {{ read?: import('./src/types.js').ReadFn, canonical?: import('./src/types.js').CanonicalFn, externals?: string[] }} */ ({
         ...readPowers,
         read: loggedRead,
-      },
+        canonical: /** @type {import('./src/types.js').CanonicalFn} */ (
+          readPowers.canonical
+        ),
+      }),
     );
 
     const code = encodeBundle(bundle);
@@ -362,18 +365,22 @@ export const makeBundleCache = (wr, cwd, readPowers, opts) => {
    * Load a bundle by target name, validating existing cache entries or creating
    * them on demand. Results are memoized per `targetName`.
    *
+   * @template {BundleCacheOperationOptions | undefined} [Opts=undefined]
    * @param {string} rootPath
    * @param {string} [targetName]
    * @param {Logger} [log]
-   * @param {BundleCacheOperationOptions} [options]
-   * @returns {Promise<unknown>}
+   * @param {Opts} [options]
+   * @returns {Promise<
+   *   Opts extends { format: infer F }
+   *     ? F extends ModuleFormat
+   *       ? import('./src/types.js').BundleSourceResult<F>
+   *       : import('./src/types.js').BundleSourceResult<'endoZipBase64'>
+   *     : import('./src/types.js').BundleSourceResult<'endoZipBase64'>
+   * >}
    */
-  const load = async (
-    rootPath,
-    targetName = readPowers.basename(rootPath, '.js'),
-    log = defaultLog,
-    options = {},
-  ) => {
+  const load = async (rootPath, targetName, log, options) => {
+    targetName = targetName ?? readPowers.basename(rootPath, '.js');
+    log = log ?? defaultLog;
     const found = loaded.get(targetName);
     // console.log('load', { targetName, found: !!found, rootPath });
     if (found && found.rootPath === rootPath) {

packages/bundle-source/package.json

@@ -40,7 +40,7 @@
     "c8": "catalog:dev",
     "eslint": "catalog:dev",
     "ses": "workspace:^",
-    "typescript": "~5.9.2"
+    "typescript": "catalog:dev"
   },
   "keywords": [],
   "files": [

packages/bundle-source/src/endo.js

@@ -189,6 +189,7 @@ export const makeBundlingKit = (
     };
   }
 
+  /** @type {import('../../compartment-mapper/src/types.js').ParserImplementation} */
   const mtsParser = {
     parse(
       sourceBytes,
@@ -212,6 +213,7 @@ export const makeBundlingKit = (
     synchronous: false,
   };
 
+  /** @type {import('../../compartment-mapper/src/types.js').ParserImplementation} */
   const ctsParser = {
     parse(
       sourceBytes,

packages/bundle-source/src/types.ts

@@ -78,12 +78,28 @@ export interface BundleCache {
     log?: Logger | undefined,
     options?: BundleCacheOperationOptions | undefined,
   ) => Promise<BundleMeta>;
-  load: (
+  /**
+   * The result type is conditional on the `format` option:
+   * - omitted → `BundleSourceResult<'endoZipBase64'>` (the default)
+   * - present → `BundleSourceResult<format>`
+   *
+   * Callers that don't pass a `format` option get the default
+   * `endoZipBase64` shape directly. Callers that pass a known literal
+   * format get the corresponding bundle shape. Callers that pass a
+   * runtime-typed `ModuleFormat` get the union of all possible shapes.
+   */
+  load: <Opts extends BundleCacheOperationOptions | undefined = undefined>(
     rootPath: string,
     targetName?: string | undefined,
     log?: Logger | undefined,
-    options?: BundleCacheOperationOptions | undefined,
-  ) => Promise<unknown>;
+    options?: Opts,
+  ) => Promise<
+    Opts extends { format: infer F }
+      ? F extends ModuleFormat
+        ? BundleSourceResult<F>
+        : BundleSourceResult<'endoZipBase64'>
+      : BundleSourceResult<'endoZipBase64'>
+  >;
 }
 
 export interface FileReader {

packages/cache-map/package.json

@@ -46,7 +46,7 @@
     "c8": "catalog:dev",
     "eslint": "catalog:dev",
     "tsd": "catalog:dev",
-    "typescript": "~5.9.2"
+    "typescript": "catalog:dev"
   },
   "files": [
     "./*.d.ts",

packages/captp/package.json

@@ -55,7 +55,7 @@
     "c8": "catalog:dev",
     "eslint": "catalog:dev",
     "ses": "workspace:^",
-    "typescript": "~5.9.2"
+    "typescript": "catalog:dev"
   },
   "dependencies": {
     "@endo/errors": "workspace:^",

packages/captp/src/captp.js

@@ -224,6 +224,7 @@ export const makeCapTP = (
 
   /** @type {any} */
   let unplug = false;
+  /** @type {(reason?: any, returnIt?: boolean) => Promise<any>} */
   const quietReject = (reason = undefined, returnIt = true) => {
     if ((unplug === false || reason !== unplug) && reason !== undefined) {
       onReject(reason);
@@ -657,7 +658,7 @@ export const makeCapTP = (
         } catch (error) {
           // Promote serialization errors to rejections.
           isReject = true;
-          serial = serialize(harden(error));
+          serial = serialize(harden(/** @type {any} */ (error)));
         }
 
         send({
@@ -758,7 +759,10 @@ export const makeCapTP = (
           if (!e) {
             Fail`trapGuest expected trapHost AsyncIterator(${questionID}) to be done, but it wasn't`;
           }
-          annotateError(e, X`trapHost AsyncIterator(${questionID}) threw`);
+          annotateError(
+            /** @type {Error} */ (e),
+            X`trapHost AsyncIterator(${questionID}) threw`,
+          );
           throw e;
         }
       };

packages/check-bundle/package.json

@@ -61,7 +61,7 @@
     "eslint-plugin-import": "^2.31.0",
     "prettier": "^3.5.3",
     "ses": "workspace:^",
-    "typescript": "~5.9.2"
+    "typescript": "catalog:dev"
   },
   "files": [
     "./*.d.ts",

packages/cjs-module-analyzer/index.js

@@ -74,11 +74,12 @@ export function analyzeCommonJS(cjsSource, name = '<unknown>') {
   try {
     parseSource(cjsSource);
   } catch (e) {
-    e.message += `\n  at ${name}:${
+    const err = /** @type {Error & { loc?: number }} */ (e);
+    err.message += `\n  at ${name}:${
       cjsSource.slice(0, pos).split('\n').length
     }:${pos - cjsSource.lastIndexOf('\n', pos - 1)}`;
-    e.loc = pos;
-    throw e;
+    err.loc = pos;
+    throw err;
   }
   const result = {
     exports: [...myexports].filter(expt => !unsafeGetters.has(expt)),

packages/cjs-module-analyzer/package.json

@@ -35,7 +35,7 @@
     "ava": "catalog:dev",
     "c8": "catalog:dev",
     "eslint": "catalog:dev",
-    "typescript": "~5.9.2"
+    "typescript": "catalog:dev"
   },
   "files": [
     "./*.d.ts",

packages/cli/package.json

@@ -58,7 +58,7 @@
     "eslint-plugin-eslint-comments": "^3.2.0",
     "eslint-plugin-import": "^2.31.0",
     "execa": "^9.3.0",
-    "typescript": "~5.9.2"
+    "typescript": "catalog:dev"
   },
   "files": [
     "./*.d.ts",

packages/cli/test/_daemon-context.js

@@ -1,4 +1,4 @@
-/** @import { Context } from './types' */
+/** @import { Context } from './_types.js' */
 
 /**
  * Provides test setup and teardown hooks that purge the local endo

packages/cli/test/_section.js

@@ -1,6 +1,6 @@
-/** @import {Execa} from 'execa' */
-/** @import {t} from 'ava' */
-/** @import {TestRoutine} from './types' */
+/** @import {ExecaMethod} from 'execa' */
+/** @import {ExecutionContext} from 'ava' */
+/** @import {TestCommand, TestRoutine} from './_types.js' */
 
 /**
  * Transforms a testRoutine into an ava test.
@@ -12,9 +12,9 @@
  * when run under a vscode JavaScript Debug Terminal
  * @see https://github.com/endojs/endo/issues/2702
  *
- * @param {Execa} execa - the command execution environment
+ * @param {ExecaMethod} execa - the command execution environment
  * @param {TestRoutine} testRoutine - the test logic implementation
- * @returns {(t: t) => Promise<void>}
+ * @returns {(t: ExecutionContext) => Promise<void>}
  */
 export function makeSectionTest(execa, testRoutine) {
   return async t => {
@@ -25,13 +25,15 @@ export function makeSectionTest(execa, testRoutine) {
         errMsg,
       );
     };
+    /** @type {TestCommand} */
     const testCommand = async (command, expectation) => {
       const result = await command;
       if (expectation !== undefined) {
         const errMsg = JSON.stringify({ expectation, result }, null, 2);
         matchExpecation(expectation.stdout ?? '', result.stdout, errMsg);
         matchExpecation(expectation.stderr ?? /.*/, result.stderr, errMsg);
       }
+      return true;
     };
     await testRoutine(execa, testCommand);
   };

packages/cli/test/_with-context.js

@@ -1,4 +1,4 @@
-/** @import {Context, TestRoutine} from '../types' */
+/** @import {Context, TestRoutine} from './_types.js' */
 /**
  * Creates a wrapper which wraps a test routine with an execa-curried setup and teardown routine.
  *

packages/cli/test/demo/counter-example.js

@@ -1,4 +1,4 @@
-/** @import {Context, TestRoutine} from '../types' */
+/** @import {Context, TestRoutine} from '../_types.js' */
 
 /** @type {TestRoutine} */
 export const section = async (execa, testLine) => {

packages/cli/test/demo/doubler-agent.js

@@ -1,4 +1,4 @@
-/** @import {Context, TestRoutine} from '../types' */
+/** @import {Context, TestRoutine} from '../_types.js' */
 
 /** @type {TestRoutine} */
 export const section = async (execa, testLine) => {

packages/cli/test/demo/mailboxes-are-symmetric.js

@@ -1,4 +1,4 @@
-/** @import {TestRoutine} from '../types' */
+/** @import {TestRoutine} from '../_types.js' */
 
 /** @type {TestRoutine} */
 export const section = async (execa, testLine) => {

packages/cli/test/demo/names-in-transit.js

@@ -1,4 +1,4 @@
-/** @import {Context, TestRoutine} from '../types' */
+/** @import {Context, TestRoutine} from '../_types.js' */
 
 /** @type {TestRoutine} */
 export const section = async (execa, testLine) => {

packages/cli/test/demo/sending-messages.js

@@ -1,4 +1,4 @@
-/** @import {Context, TestRoutine} from '../types' */
+/** @import {Context, TestRoutine} from '../_types.js' */
 
 /** @type {TestRoutine} */
 export const section = async (execa, testLine) => {

packages/common/apply-labeling-error.js

@@ -41,7 +41,7 @@ export const applyLabelingError = (func, args, label = undefined) => {
   try {
     result = func(...args);
   } catch (err) {
-    throwLabeled(err, label);
+    throwLabeled(/** @type {Error} */ (err), label);
   }
   if (isPromise(result)) {
     // Cannot be at-ts-expect-error because there is no type error locally.

packages/common/package.json

@@ -53,7 +53,7 @@
     "eslint": "catalog:dev",
     "ses": "workspace:^",
     "tsd": "catalog:dev",
-    "typescript": "~5.9.2"
+    "typescript": "catalog:dev"
   },
   "files": [
     "./*.d.ts",

packages/compartment-mapper/package.json

@@ -81,7 +81,7 @@
     "eslint-plugin-import": "^2.31.0",
     "prettier": "^3.5.3",
     "ses": "workspace:^",
-    "typescript": "~5.9.2"
+    "typescript": "catalog:dev"
   },
   "files": [
     "./*.d.ts",