fix(env-options)!: env-options harmony

packages/env-options/README.md

@@ -34,24 +34,28 @@ optionally holding a property with the same name as the option,
 whose value is the configuration setting of that option.
 
 ```js
-import { makeEnvironmentCaptor } from '@endo/env-options';
-const { getEnvironmentOption } = makeEnvironmentCaptor(globalThis);
+import { getEnvironmentOption } from '@endo/env-options';
 const FooBarOption = getEnvironmentOption('FOO_BAR', 'absent');
 ```
 
 The first argument to `getEnvironmentOption` is the name of the option.
 The value of `FooBarOption` would then be the value of
 `globalThis.process.env.FOO_BAR`, if present.
-If setting is either absent or `undefined`, the default `'absent'`
-would be used instead.
+If value is either absent or `undefined`, the second argument,
+such as `'absent'`, would be used instead.
 
 In either case, reflecting Unix environment variable expectations,
 the resulting setting must be a string.
 This restriction also helps ensure that this channel is used only to pass data,
 not authority beyond the ability to read this global state.
 
-The `makeEnvironmentCaptor` function also returns a
-`getCapturedEnvironmentOptionNames` function for use to give feedback about
+The `'@endo/env-options'` module also exports a lower-level
+`makeEnvironmentCaptor` that you can apply to whatever object you wish to treat
+as a global, such as the global of another compartment. It returns an entagled
+pair of a `getEnvironmentOption` function as above, and a
+`getCapturedEnvironmentOptionNames` function for that returns an array of
+the option names used by that `getEnvironmentOption` function. This is
+useful to give feedback about
 which environment variables were actually read, for diagnostic purposes.
 For example, the
 ses-shim `lockdown` once contained code such as the following, to explain which

packages/env-options/src/env-options.js

@@ -1,3 +1,4 @@
+/* global globalThis */
 // @ts-check
 
 // `@endo/env-options` needs to be imported quite early, and so should
@@ -17,6 +18,8 @@ const uncurryThis =
   (receiver, ...args) =>
     apply(fn, receiver, args);
 const arrayPush = uncurryThis(Array.prototype.push);
+const arrayIncludes = uncurryThis(Array.prototype.includes);
+const stringSplit = uncurryThis(String.prototype.split);
 
 const q = JSON.stringify;
 
@@ -47,13 +50,16 @@ export const makeEnvironmentCaptor = aGlobal => {
    *
    * @param {string} optionName
    * @param {string} defaultSetting
+   * @param {string[]} [optOtherNames]
    * @returns {string}
    */
-  const getEnvironmentOption = (optionName, defaultSetting) => {
-    // eslint-disable-next-line @endo/no-polymorphic-call
+  const getEnvironmentOption = (
+    optionName,
+    defaultSetting,
+    optOtherNames = undefined,
+  ) => {
     typeof optionName === 'string' ||
       Fail`Environment option name ${q(optionName)} must be a string.`;
-    // eslint-disable-next-line @endo/no-polymorphic-call
     typeof defaultSetting === 'string' ||
       Fail`Environment option default setting ${q(
         defaultSetting,
@@ -68,7 +74,6 @@ export const makeEnvironmentCaptor = aGlobal => {
         if (optionName in globalEnv) {
           arrayPush(capturedEnvironmentOptionNames, optionName);
           const optionValue = globalEnv[optionName];
-          // eslint-disable-next-line @endo/no-polymorphic-call
           typeof optionValue === 'string' ||
             Fail`Environment option named ${q(
               optionName,
@@ -79,15 +84,52 @@ export const makeEnvironmentCaptor = aGlobal => {
         }
       }
     }
+    optOtherNames === undefined ||
+      setting === defaultSetting ||
+      arrayIncludes(optOtherNames, setting) ||
+      Fail`Unrecognized ${q(optionName)} value ${q(
+        setting,
+      )}. Expected one of ${q([defaultSetting, ...optOtherNames])}`;
     return setting;
   };
   freeze(getEnvironmentOption);
 
+  /**
+   * @param {string} optionName
+   * @returns {string[]}
+   */
+  const getEnvironmentOptionsList = optionName => {
+    const option = getEnvironmentOption(optionName, '');
+    return option === '' ? [] : stringSplit(option, ',');
+  };
+  freeze(getEnvironmentOptionsList);
+
+  const environmentOptionsListHas = (optionName, element) =>
+    arrayIncludes(getEnvironmentOptionsList(optionName), element);
+
   const getCapturedEnvironmentOptionNames = () => {
     return freeze([...capturedEnvironmentOptionNames]);
   };
   freeze(getCapturedEnvironmentOptionNames);
 
-  return freeze({ getEnvironmentOption, getCapturedEnvironmentOptionNames });
+  return freeze({
+    getEnvironmentOption,
+    getEnvironmentOptionsList,
+    environmentOptionsListHas,
+    getCapturedEnvironmentOptionNames,
+  });
 };
 freeze(makeEnvironmentCaptor);
+
+/**
+ * For the simple case, where the global in question is `globalThis` and no
+ * reporting of option names is desired.
+ *
+ * TODO For this simple case, we should not track the
+ * `capturedEnvironmentOptionNames` since no one can observe them.
+ */
+export const {
+  getEnvironmentOption,
+  getEnvironmentOptionsList,
+  environmentOptionsListHas,
+} = makeEnvironmentCaptor(globalThis);

packages/eventual-send/src/track-turns.js

@@ -1,7 +1,8 @@
 /* global globalThis */
-import { makeEnvironmentCaptor } from '@endo/env-options';
-
-const { getEnvironmentOption } = makeEnvironmentCaptor(globalThis);
+import {
+  environmentOptionsListHas,
+  getEnvironmentOption,
+} from '@endo/env-options';
 
 // NOTE: We can't import these because they're not in scope before lockdown.
 // import { assert, details as X, Fail } from '@agoric/assert';
@@ -17,18 +18,13 @@ let hiddenPriorError;
 let hiddenCurrentTurn = 0;
 let hiddenCurrentEvent = 0;
 
-const DEBUG = getEnvironmentOption('DEBUG', '');
-
 // Turn on if you seem to be losing error logging at the top of the event loop
-const VERBOSE = DEBUG.split(':').includes('track-turns');
+const VERBOSE = environmentOptionsListHas('DEBUG', 'track-turns');
 
 // Track-turns is disabled by default and can be enabled by an environment
 // option.
-const TRACK_TURNS = getEnvironmentOption('TRACK_TURNS', 'disabled');
-if (TRACK_TURNS !== 'enabled' && TRACK_TURNS !== 'disabled') {
-  throw TypeError(`unrecognized TRACK_TURNS ${JSON.stringify(TRACK_TURNS)}`);
-}
-const ENABLED = (TRACK_TURNS || 'disabled') === 'enabled';
+const ENABLED =
+  getEnvironmentOption('TRACK_TURNS', 'disabled', ['enabled']) === 'enabled';
 
 // We hoist the following functions out of trackTurns() to discourage the
 // closures from holding onto 'args' or 'func' longer than necessary,

packages/exo/src/exo-makers.js

@@ -1,17 +1,13 @@
-/* global globalThis */
 /// <reference types="ses"/>
-import { makeEnvironmentCaptor } from '@endo/env-options';
+import { environmentOptionsListHas } from '@endo/env-options';
 import { objectMap } from '@endo/patterns';
 
 import { defendPrototype, defendPrototypeKit } from './exo-tools.js';
 
 const { create, seal, freeze, defineProperty } = Object;
 
-const { getEnvironmentOption } = makeEnvironmentCaptor(globalThis);
-const DEBUG = getEnvironmentOption('DEBUG', '');
-
 // Turn on to give each exo instance its own toStringTag value.
-const LABEL_INSTANCES = DEBUG.split(',').includes('label-instances');
+const LABEL_INSTANCES = environmentOptionsListHas('DEBUG', 'label-instances');
 
 const makeSelf = (proto, instanceCount) => {
   const self = create(proto);

packages/ses/src/lockdown-shim.js

@@ -14,7 +14,7 @@
 
 // @ts-check
 
-import { makeEnvironmentCaptor } from '@endo/env-options';
+import { getEnvironmentOption as getenv } from '@endo/env-options';
 import {
   FERAL_FUNCTION,
   FERAL_EVAL,
@@ -152,8 +152,6 @@ export const repairIntrinsics = (options = {}) => {
   // [`stackFiltering` options](https://github.com/Agoric/SES-shim/blob/master/packages/ses/lockdown-options.md#stackfiltering-options)
   // for an explanation.
 
-  const { getEnvironmentOption: getenv } = makeEnvironmentCaptor(globalThis);
-
   const {
     errorTaming = getenv('LOCKDOWN_ERROR_TAMING', 'safe'),
     errorTrapping = getenv('LOCKDOWN_ERROR_TRAPPING', 'platform'),