refactor(pass-style): use confirm/reject pattern in pass-style

packages/pass-style/NEWS.md

@@ -1,5 +1,9 @@
 User-visible changes in `@endo/pass-style`:
 
+# Next release
+
+- deprecates `assertChecker`. Use `Fail` in the confirm/reject pattern instead, as supported by `@endo/errors/rejector.js`.
+
 # 1.6.3 (2025-07-11)
 
 - The exported function name `isObject` is ambiguous. It is unclear whether it

packages/pass-style/src/byteArray.js

@@ -49,9 +49,9 @@ const { immutableArrayBufferPrototype, immutableGetter } =
 export const ByteArrayHelper = harden({
   styleName: 'byteArray',
 
-  canBeValid: (candidate, check = undefined) =>
+  confirmCanBeValid: (candidate, reject) =>
     (candidate instanceof ArrayBuffer && candidate.immutable) ||
-    (!!check && check(false, X`Immutable ArrayBuffer expected: ${candidate}`)),
+    (reject && reject`Immutable ArrayBuffer expected: ${candidate}`),
 
   assertRestValid: (candidate, _passStyleOfRecur) => {
     getPrototypeOf(candidate) === immutableArrayBufferPrototype ||

packages/pass-style/src/copyArray.js

@@ -1,7 +1,7 @@
 /// <reference types="ses"/>
 
-import { X } from '@endo/errors';
-import { assertChecker, getOwnDataDescriptor } from './passStyle-helpers.js';
+import { Fail, X } from '@endo/errors';
+import { confirmOwnDataDescriptor } from './passStyle-helpers.js';
 
 const { getPrototypeOf } = Object;
 const { ownKeys } = Reflect;
@@ -14,23 +14,22 @@ const { isArray, prototype: arrayPrototype } = Array;
 export const CopyArrayHelper = harden({
   styleName: 'copyArray',
 
-  canBeValid: (candidate, check = undefined) =>
-    isArray(candidate) ||
-    (!!check && check(false, X`Array expected: ${candidate}`)),
+  confirmCanBeValid: (candidate, reject) =>
+    isArray(candidate) || (reject && reject`Array expected: ${candidate}`),
 
   assertRestValid: (candidate, passStyleOfRecur) => {
     getPrototypeOf(candidate) === arrayPrototype ||
       assert.fail(X`Malformed array: ${candidate}`, TypeError);
     // Since we're already ensured candidate is an array, it should not be
     // possible for the following get to fail.
     const len = /** @type {number} */ (
-      getOwnDataDescriptor(candidate, 'length', false, assertChecker).value
+      confirmOwnDataDescriptor(candidate, 'length', false, Fail).value
     );
     // Validate that each index property is own/data/enumerable
     // and its associated value is recursively passable.
     for (let i = 0; i < len; i += 1) {
       passStyleOfRecur(
-        getOwnDataDescriptor(candidate, i, true, assertChecker).value,
+        confirmOwnDataDescriptor(candidate, i, true, Fail).value,
       );
     }
     // Expect one key per index plus one for 'length'.

packages/pass-style/src/copyRecord.js

@@ -1,80 +1,70 @@
 /// <reference types="ses"/>
 
-/** @import {Checker} from './types.js' */
-
-import {
-  assertChecker,
-  getOwnDataDescriptor,
-  CX,
-} from './passStyle-helpers.js';
+import { Fail } from '@endo/errors';
+import { confirmOwnDataDescriptor } from './passStyle-helpers.js';
 import { canBeMethod } from './remotable.js';
 
+/**
+ * @import {Rejector} from '@endo/errors/rejector.js';
+ * @import {PassStyleHelper} from './internal-types.js';
+ */
+
 const { ownKeys } = Reflect;
 const { getPrototypeOf, prototype: objectPrototype } = Object;
 
 /**
  * @param {unknown} candidate
- * @param {Checker} [check]
+ * @param {Rejector} reject
  */
-const checkObjectPrototype = (candidate, check = undefined) => {
+const confirmObjectPrototype = (candidate, reject) => {
   return (
     getPrototypeOf(candidate) === objectPrototype ||
-    (!!check &&
-      CX(check)`Records must inherit from Object.prototype: ${candidate}`)
+    (reject && reject`Records must inherit from Object.prototype: ${candidate}`)
   );
 };
 
 /**
  * @param {unknown} candidate
  * @param {PropertyKey} key
  * @param {unknown} value
- * @param {Checker} [check]
+ * @param {Rejector} reject
  */
-const checkPropertyCanBeValid = (candidate, key, value, check = undefined) => {
+const confirmPropertyCanBeValid = (candidate, key, value, reject) => {
   return (
     (typeof key === 'string' ||
-      (!!check &&
-        CX(
-          check,
-        )`Records can only have string-named properties: ${candidate}`)) &&
+      (reject &&
+        reject`Records can only have string-named properties: ${candidate}`)) &&
     (!canBeMethod(value) ||
-      (!!check &&
+      (reject &&
         // TODO: Update message now that there is no such thing as "implicit Remotable".
-        CX(
-          check,
-        )`Records cannot contain non-far functions because they may be methods of an implicit Remotable: ${candidate}`))
+        reject`Records cannot contain non-far functions because they may be methods of an implicit Remotable: ${candidate}`))
   );
 };
 
 /**
  *
- * @type {import('./internal-types.js').PassStyleHelper}
+ * @type {PassStyleHelper}
  */
 export const CopyRecordHelper = harden({
   styleName: 'copyRecord',
 
-  canBeValid: (candidate, check = undefined) => {
+  confirmCanBeValid: (candidate, reject) => {
     return (
-      checkObjectPrototype(candidate, check) &&
+      confirmObjectPrototype(candidate, reject) &&
       // Reject any candidate with a symbol-keyed property or method-like property
       // (such input is potentially a Remotable).
       ownKeys(candidate).every(key =>
-        checkPropertyCanBeValid(candidate, key, candidate[key], check),
+        confirmPropertyCanBeValid(candidate, key, candidate[key], reject),
       )
     );
   },
 
   assertRestValid: (candidate, passStyleOfRecur) => {
     // Validate that each own property has a recursively passable associated
-    // value (we already know from canBeValid that the other constraints are
+    // value (we already know from confirmCanBeValid that the other constraints are
     // satisfied).
     for (const name of ownKeys(candidate)) {
-      const { value } = getOwnDataDescriptor(
-        candidate,
-        name,
-        true,
-        assertChecker,
-      );
+      const { value } = confirmOwnDataDescriptor(candidate, name, true, Fail);
       passStyleOfRecur(value);
     }
   },

packages/pass-style/src/error.js

@@ -1,10 +1,12 @@
 /// <reference types="ses"/>
 
-import { q } from '@endo/errors';
-import { assertChecker, CX } from './passStyle-helpers.js';
+import { Fail, q, hideAndHardenFunction } from '@endo/errors';
 
-/** @import {PassStyleHelper} from './internal-types.js' */
-/** @import {Checker, PassStyle, PassStyleOf} from './types.js' */
+/**
+ * @import {Rejector} from '@endo/errors/rejector.js';
+ * @import {PassStyleHelper} from './internal-types.js';
+ * @import {PassStyle} from './types.js';
+ */
 
 const { getPrototypeOf, getOwnPropertyDescriptors, hasOwn, entries } = Object;
 
@@ -50,17 +52,17 @@ harden(getErrorConstructor);
 
 /**
  * @param {unknown} candidate
- * @param {Checker} [check]
+ * @param {Rejector} reject
  * @returns {boolean}
  */
-const checkErrorLike = (candidate, check = undefined) => {
+const confirmErrorLike = (candidate, reject) => {
   // TODO: Need a better test than instanceof
   return (
     candidate instanceof Error ||
-    (!!check && CX(check)`Error expected: ${candidate}`)
+    (reject && reject`Error expected: ${candidate}`)
   );
 };
-harden(checkErrorLike);
+harden(confirmErrorLike);
 /// <reference types="ses"/>
 
 /**
@@ -81,34 +83,34 @@ harden(checkErrorLike);
  * @param {unknown} candidate
  * @returns {boolean}
  */
-export const isErrorLike = candidate => checkErrorLike(candidate);
-harden(isErrorLike);
+export const isErrorLike = candidate => confirmErrorLike(candidate, false);
+hideAndHardenFunction(isErrorLike);
 
 /**
  * @param {string} propName
  * @param {PropertyDescriptor} desc
  * @param {(val: any) => PassStyle} passStyleOfRecur
- * @param {Checker} [check]
+ * @param {Rejector} reject
  * @returns {boolean}
  */
-export const checkRecursivelyPassableErrorPropertyDesc = (
+export const confirmRecursivelyPassableErrorPropertyDesc = (
   propName,
   desc,
   passStyleOfRecur,
-  check = undefined,
+  reject,
 ) => {
   if (desc.enumerable) {
     return (
-      !!check &&
-      CX(check)`Passable Error ${q(
+      reject &&
+      reject`Passable Error ${q(
         propName,
       )} own property must not be enumerable: ${desc}`
     );
   }
   if (!hasOwn(desc, 'value')) {
     return (
-      !!check &&
-      CX(check)`Passable Error ${q(
+      reject &&
+      reject`Passable Error ${q(
         propName,
       )} own property must be a data property: ${desc}`
     );
@@ -119,95 +121,90 @@ export const checkRecursivelyPassableErrorPropertyDesc = (
     case 'stack': {
       return (
         typeof value === 'string' ||
-        (!!check &&
-          CX(check)`Passable Error ${q(
+        (reject &&
+          reject`Passable Error ${q(
             propName,
           )} own property must be a string: ${value}`)
       );
     }
     case 'cause': {
       // eslint-disable-next-line no-use-before-define
-      return checkRecursivelyPassableError(value, passStyleOfRecur, check);
+      return confirmRecursivelyPassableError(value, passStyleOfRecur, reject);
     }
     case 'errors': {
       if (!Array.isArray(value) || passStyleOfRecur(value) !== 'copyArray') {
         return (
-          !!check &&
-          CX(check)`Passable Error ${q(
+          reject &&
+          reject`Passable Error ${q(
             propName,
           )} own property must be a copyArray: ${value}`
         );
       }
       return value.every(err =>
         // eslint-disable-next-line no-use-before-define
-        checkRecursivelyPassableError(err, passStyleOfRecur, check),
+        confirmRecursivelyPassableError(err, passStyleOfRecur, reject),
       );
     }
     default: {
       break;
     }
   }
   return (
-    !!check &&
-    CX(check)`Passable Error has extra unpassed property ${q(propName)}`
+    reject && reject`Passable Error has extra unpassed property ${q(propName)}`
   );
 };
-harden(checkRecursivelyPassableErrorPropertyDesc);
+harden(confirmRecursivelyPassableErrorPropertyDesc);
 
 /**
  * @param {unknown} candidate
  * @param {(val: any) => PassStyle} passStyleOfRecur
- * @param {Checker} [check]
+ * @param {Rejector} reject
  * @returns {boolean}
  */
-export const checkRecursivelyPassableError = (
+export const confirmRecursivelyPassableError = (
   candidate,
   passStyleOfRecur,
-  check = undefined,
+  reject,
 ) => {
-  if (!checkErrorLike(candidate, check)) {
+  if (!confirmErrorLike(candidate, reject)) {
     return false;
   }
   const proto = getPrototypeOf(candidate);
   const { name } = proto;
   const errConstructor = getErrorConstructor(name);
   if (errConstructor === undefined || errConstructor.prototype !== proto) {
     return (
-      !!check &&
-      CX(
-        check,
-      )`Passable Error must inherit from an error class .prototype: ${candidate}`
+      reject &&
+      reject`Passable Error must inherit from an error class .prototype: ${candidate}`
     );
   }
   const descs = getOwnPropertyDescriptors(candidate);
   if (!('message' in descs)) {
     return (
-      !!check &&
-      CX(
-        check,
-      )`Passable Error must have an own "message" string property: ${candidate}`
+      reject &&
+      reject`Passable Error must have an own "message" string property: ${candidate}`
     );
   }
 
   return entries(descs).every(([propName, desc]) =>
-    checkRecursivelyPassableErrorPropertyDesc(
+    confirmRecursivelyPassableErrorPropertyDesc(
       propName,
       desc,
       passStyleOfRecur,
-      check,
+      reject,
     ),
   );
 };
-harden(checkRecursivelyPassableError);
+harden(confirmRecursivelyPassableError);
 
 /**
  * @type {PassStyleHelper}
  */
 export const ErrorHelper = harden({
   styleName: 'error',
 
-  canBeValid: checkErrorLike,
+  confirmCanBeValid: confirmErrorLike,
 
   assertRestValid: (candidate, passStyleOfRecur) =>
-    checkRecursivelyPassableError(candidate, passStyleOfRecur, assertChecker),
+    confirmRecursivelyPassableError(candidate, passStyleOfRecur, Fail),
 });

packages/pass-style/src/internal-types.js

@@ -1,8 +1,9 @@
 export {};
 
-/** @import {Checker} from './types.js' */
-/** @import {PassStyle} from './types.js' */
-/** @import {PassStyleOf} from './types.js' */
+/**
+ * @import {Rejector} from '@endo/errors/rejector.js';
+ * @import {PassStyle} from './types.js';
+ */
 
 /**
  * The PassStyleHelper are only used to make a `passStyleOf` function.
@@ -17,11 +18,12 @@ export {};
  *
  * @typedef {object} PassStyleHelper
  * @property {PassStyle} styleName
- * @property {(candidate: any, check?: Checker) => boolean} canBeValid
- * If `canBeValid` returns true, then the candidate would
+ * @property {(candidate: any, reject: Rejector) => boolean} confirmCanBeValid
+ * If `confirmCanBeValid` returns true, then the candidate would
  * definitely not be valid for any of the other helpers.
  * `assertRestValid` still needs to be called to determine if it
- * actually is valid, but only after the `canBeValid` check has passed.
+ * actually is valid, but only after the `confirmCanBeValid` check has passed.
+ *
  * @property {(candidate: any,
  *             passStyleOfRecur: (val: any) => PassStyle
  *            ) => void} assertRestValid