diff --git a/packages/auth/tsconfig.test.json b/packages/auth/tsconfig.test.json
index 841f60d8bf..4262bda5a5 100644
--- a/packages/auth/tsconfig.test.json
+++ b/packages/auth/tsconfig.test.json
@@ -15,6 +15,11 @@
   // about them and `tsc` is the only thing that can.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/collaboration/tsconfig.test.json b/packages/collaboration/tsconfig.test.json
index 308c3fa0e9..b133a51efd 100644
--- a/packages/collaboration/tsconfig.test.json
+++ b/packages/collaboration/tsconfig.test.json
@@ -9,6 +9,11 @@
   // and only `tsc` can check.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/core/tsconfig.test.json b/packages/core/tsconfig.test.json
index d253aba325..d89037442a 100644
--- a/packages/core/tsconfig.test.json
+++ b/packages/core/tsconfig.test.json
@@ -26,7 +26,7 @@
     // not inherit `composite` / `declaration` from the build config.
     "composite": false,
     "declaration": false,
-    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     // Naming `types` at all switches off automatic `@types/*` inclusion.
     // `node` is required: several suites read fixtures off disk through
     // `node:fs` / `node:url` / `__dirname`, and the ActionRunner suites stub
diff --git a/packages/create-plugin/tsconfig.test.json b/packages/create-plugin/tsconfig.test.json
index 543e8981fe..03d92e1adf 100644
--- a/packages/create-plugin/tsconfig.test.json
+++ b/packages/create-plugin/tsconfig.test.json
@@ -7,6 +7,11 @@
   // this project CHAINED from `type-check` — the script CI actually runs.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // `templates.test.ts` reads the repo-root manifest off disk (readFileSync,
     // fileURLToPath, isBuiltin) to assert the generated dependency ranges are
diff --git a/packages/fields/tsconfig.test.json b/packages/fields/tsconfig.test.json
index 2f19f19665..e1cf9469c7 100644
--- a/packages/fields/tsconfig.test.json
+++ b/packages/fields/tsconfig.test.json
@@ -29,7 +29,7 @@
     // Deliberately NOT raised to ES2022. Measured: no test file in this package
     // reaches for `Array.prototype.at` or any other ES2021+ builtin, so the
     // tests are held to the same lib the shipped SOURCE targets.
-    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     //
     // `types` is deliberately NOT named, unlike plugin-dashboard's. Naming it
     // switches off automatic `@types/*` inclusion, and this package's build
diff --git a/packages/i18n/tsconfig.test.json b/packages/i18n/tsconfig.test.json
index 169785163d..54be2212e2 100644
--- a/packages/i18n/tsconfig.test.json
+++ b/packages/i18n/tsconfig.test.json
@@ -16,7 +16,7 @@
     "composite": false,
     "declaration": false,
     "jsx": "react-jsx",
-    "lib": ["ES2020", "DOM"],
+    "lib": ["ES2022", "DOM"],
     // Two global augmentations, neither of them an import:
     //   - `node` for the seven locale-parity / namespace suites, which walk the
     //     locale packs off disk (`readFileSync`, `__dirname`, `node:path`) to
diff --git a/packages/layout/tsconfig.test.json b/packages/layout/tsconfig.test.json
index df7dd1b994..e5f82deedb 100644
--- a/packages/layout/tsconfig.test.json
+++ b/packages/layout/tsconfig.test.json
@@ -5,6 +5,11 @@
   // them, so a test could assert a contract the compiler never checked.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // `page-node-renderer-stays-deleted.test.ts` reads this package's own
     // sources off disk to prove the renderer objectui#3223 removed has not been
diff --git a/packages/permissions/tsconfig.test.json b/packages/permissions/tsconfig.test.json
index 9fecaa7c83..4f5f95d90f 100644
--- a/packages/permissions/tsconfig.test.json
+++ b/packages/permissions/tsconfig.test.json
@@ -5,6 +5,11 @@
   // them, so a test could assert a contract the compiler never checked.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/plugin-ai/tsconfig.test.json b/packages/plugin-ai/tsconfig.test.json
index 03025bb268..8c1fd50f15 100644
--- a/packages/plugin-ai/tsconfig.test.json
+++ b/packages/plugin-ai/tsconfig.test.json
@@ -11,6 +11,11 @@
   // scripts/check-type-check-coverage.mjs` exits 1 naming both of them.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // `registrationInputs-8178.test.ts` reads the three component sources off
     // disk (`node:fs` / `node:path` / `node:url`) to derive the keys each
diff --git a/packages/plugin-calendar/tsconfig.test.json b/packages/plugin-calendar/tsconfig.test.json
index 99d7e7aac9..a63c3bb211 100644
--- a/packages/plugin-calendar/tsconfig.test.json
+++ b/packages/plugin-calendar/tsconfig.test.json
@@ -5,6 +5,11 @@
   // them, so a test could assert a contract the compiler never checked.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/plugin-charts/tsconfig.test.json b/packages/plugin-charts/tsconfig.test.json
index fca83ed396..ad2e307ef6 100644
--- a/packages/plugin-charts/tsconfig.test.json
+++ b/packages/plugin-charts/tsconfig.test.json
@@ -4,6 +4,11 @@
   // already reads schema-catalog fixtures off disk from a `*-6939` render pin.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/plugin-chatbot/tsconfig.test.json b/packages/plugin-chatbot/tsconfig.test.json
index ddfd94e0f9..fb9a6fcdd8 100644
--- a/packages/plugin-chatbot/tsconfig.test.json
+++ b/packages/plugin-chatbot/tsconfig.test.json
@@ -15,6 +15,11 @@
   // about them and `tsc` is the only thing that can.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/plugin-dashboard/tsconfig.test.json b/packages/plugin-dashboard/tsconfig.test.json
index 7e9212f175..a4d9eb18a7 100644
--- a/packages/plugin-dashboard/tsconfig.test.json
+++ b/packages/plugin-dashboard/tsconfig.test.json
@@ -26,7 +26,7 @@
     // whose suites needed ES2022 for `Array.prototype.at`. Measured: this
     // package's 47 test files compile clean against the root's ES2020 baseline,
     // so the tests are held to the same lib the shipped SOURCE targets.
-    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     // Naming `types` at all switches off automatic `@types/*` inclusion.
     // `node` is load-bearing and measured: dropping it turns five suites red
     // with TS2304 `Cannot find name 'global'` — they all install a `global.fetch`
diff --git a/packages/plugin-designer/tsconfig.test.json b/packages/plugin-designer/tsconfig.test.json
index 1edf1cd83f..127225cacc 100644
--- a/packages/plugin-designer/tsconfig.test.json
+++ b/packages/plugin-designer/tsconfig.test.json
@@ -5,6 +5,11 @@
   // them, so a test could assert a contract the compiler never checked.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/plugin-detail/tsconfig.test.json b/packages/plugin-detail/tsconfig.test.json
index 4d849d8d87..b73dee249c 100644
--- a/packages/plugin-detail/tsconfig.test.json
+++ b/packages/plugin-detail/tsconfig.test.json
@@ -14,6 +14,11 @@
   // turned this project red.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/plugin-editor/tsconfig.test.json b/packages/plugin-editor/tsconfig.test.json
index b9e41af3ad..9ad3b3a231 100644
--- a/packages/plugin-editor/tsconfig.test.json
+++ b/packages/plugin-editor/tsconfig.test.json
@@ -28,7 +28,7 @@
     "jsx": "react-jsx",
     // Measured: the single suite compiles clean against the root's ES2020
     // baseline, so the test is held to the same lib the shipped SOURCE targets.
-    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     // `paths` drops the root tsconfig's source-tree mappings so `@object-ui/*`
     // resolves through each workspace dependency's built `.d.ts` rather than
     // pulling sibling package sources in as program inputs. `type-check`
diff --git a/packages/plugin-form/tsconfig.test.json b/packages/plugin-form/tsconfig.test.json
index d00c801b52..da8072d4a9 100644
--- a/packages/plugin-form/tsconfig.test.json
+++ b/packages/plugin-form/tsconfig.test.json
@@ -20,7 +20,7 @@
     // not inherit `composite` / `declaration` from the build config.
     "composite": false,
     "jsx": "react-jsx",
-    "lib": ["ES2020", "DOM"],
+    "lib": ["ES2022", "DOM"],
     // Two global augmentations, neither of them an import:
     //   - `node` for `spec-symbol-batch7.test.tsx`, which resolves
     //     `@objectstack/spec`'s own `.d.ts` off disk to read the spec's export
diff --git a/packages/plugin-gantt/tsconfig.test.json b/packages/plugin-gantt/tsconfig.test.json
index 00dce8ce94..182efe99eb 100644
--- a/packages/plugin-gantt/tsconfig.test.json
+++ b/packages/plugin-gantt/tsconfig.test.json
@@ -5,6 +5,11 @@
   // them, so a test could assert a contract the compiler never checked.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/plugin-kanban/tsconfig.test.json b/packages/plugin-kanban/tsconfig.test.json
index 7ba33f260f..1721772baa 100644
--- a/packages/plugin-kanban/tsconfig.test.json
+++ b/packages/plugin-kanban/tsconfig.test.json
@@ -5,6 +5,11 @@
   // them, so a test could assert a contract the compiler never checked.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/plugin-map/tsconfig.test.json b/packages/plugin-map/tsconfig.test.json
index 6b26d1d2ba..4e8413e5a1 100644
--- a/packages/plugin-map/tsconfig.test.json
+++ b/packages/plugin-map/tsconfig.test.json
@@ -5,6 +5,11 @@
   // them, so a test could assert a contract the compiler never checked.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/plugin-markdown/tsconfig.test.json b/packages/plugin-markdown/tsconfig.test.json
index 1edf1cd83f..127225cacc 100644
--- a/packages/plugin-markdown/tsconfig.test.json
+++ b/packages/plugin-markdown/tsconfig.test.json
@@ -5,6 +5,11 @@
   // them, so a test could assert a contract the compiler never checked.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/plugin-report/tsconfig.test.json b/packages/plugin-report/tsconfig.test.json
index be3d460a90..b903097382 100644
--- a/packages/plugin-report/tsconfig.test.json
+++ b/packages/plugin-report/tsconfig.test.json
@@ -5,6 +5,11 @@
   // them, so a test could assert a contract the compiler never checked.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing.
     "composite": false,
diff --git a/packages/plugin-tree/tsconfig.test.json b/packages/plugin-tree/tsconfig.test.json
index 1edf1cd83f..127225cacc 100644
--- a/packages/plugin-tree/tsconfig.test.json
+++ b/packages/plugin-tree/tsconfig.test.json
@@ -5,6 +5,11 @@
   // them, so a test could assert a contract the compiler never checked.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/plugin-view/tsconfig.test.json b/packages/plugin-view/tsconfig.test.json
index 3968124991..c1b15fd4d4 100644
--- a/packages/plugin-view/tsconfig.test.json
+++ b/packages/plugin-view/tsconfig.test.json
@@ -5,6 +5,11 @@
   // them, so a test could assert a contract the compiler never checked.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing.
     "composite": false,
diff --git a/packages/providers/tsconfig.test.json b/packages/providers/tsconfig.test.json
index b1db1dad27..ddbfa98265 100644
--- a/packages/providers/tsconfig.test.json
+++ b/packages/providers/tsconfig.test.json
@@ -5,6 +5,11 @@
   // them, so a test could assert a contract the compiler never checked.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/react-runtime/tsconfig.test.json b/packages/react-runtime/tsconfig.test.json
index 1edf1cd83f..127225cacc 100644
--- a/packages/react-runtime/tsconfig.test.json
+++ b/packages/react-runtime/tsconfig.test.json
@@ -5,6 +5,11 @@
   // them, so a test could assert a contract the compiler never checked.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/react/tsconfig.test.json b/packages/react/tsconfig.test.json
index aa43dc2256..4f28f19ad8 100644
--- a/packages/react/tsconfig.test.json
+++ b/packages/react/tsconfig.test.json
@@ -32,7 +32,7 @@
     // The root baseline, plus `DOM.Iterable` (which the root already sets and
     // the retired narrow project did not) — strictly wider than what compiled
     // the parity test before.
-    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     // The parity test resolves `@objectstack/spec`'s own `.d.ts` files off disk
     // (createRequire / readFileSync / node:path) to read the spec's export
     // names through the TypeScript checker. Naming `types` at all switches off
diff --git a/packages/runner/tsconfig.test.json b/packages/runner/tsconfig.test.json
index dccf88a86d..e3b3254836 100644
--- a/packages/runner/tsconfig.test.json
+++ b/packages/runner/tsconfig.test.json
@@ -5,6 +5,11 @@
   // them, so a test could assert a contract the compiler never checked.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing, so it must
     // not inherit `composite` / `declaration` from the build config.
diff --git a/packages/sdui-parser/tsconfig.test.json b/packages/sdui-parser/tsconfig.test.json
index 49dbdf50ba..0b2cce7e02 100644
--- a/packages/sdui-parser/tsconfig.test.json
+++ b/packages/sdui-parser/tsconfig.test.json
@@ -11,6 +11,11 @@
   // test resolves them the way a consumer would.
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
     "noEmit": true,
     // The package build emits `dist`; this project emits nothing.
     "composite": false,
diff --git a/packages/types/tsconfig.test.json b/packages/types/tsconfig.test.json
index 3d35df8cc3..ca5e3c7a1a 100644
--- a/packages/types/tsconfig.test.json
+++ b/packages/types/tsconfig.test.json
@@ -19,7 +19,7 @@
   "extends": "../../tsconfig.json",
   "compilerOptions": {
     "noEmit": true,
-    "lib": ["ES2020", "DOM"],
+    "lib": ["ES2022", "DOM"],
     // `spec-ui-schema-reexports.test.ts` reads sibling sources off disk to prove
     // no spec/ui zod value hides inside an `export type` block (#2561).
     "types": ["node"],
diff --git a/packages/vscode-extension/tsconfig.test.json b/packages/vscode-extension/tsconfig.test.json
index 79cdb3c029..713b4c407d 100644
--- a/packages/vscode-extension/tsconfig.test.json
+++ b/packages/vscode-extension/tsconfig.test.json
@@ -13,6 +13,11 @@
   // objectui#3009 failure itself.
   "extends": "./tsconfig.json",
   "compilerOptions": {
+    // objectui#8691: test programs only. One notch above the package build's
+    // ES2020, mirroring packages/app-shell. The package SOURCE tsconfig is
+    // untouched, so what this package SHIPS still compiles at the ES2020
+    // baseline; nothing here is emitted.
+    "lib": ["ES2022"],
     // A checking project, never an emitting one.
     "noEmit": true,
     "declaration": false,