refactor(domain): one owner for the non-array record predicate (#10588)

* refactor(domain): one owner for the non-array record predicate

Thirty-four source files each declared isRecord as a non-null object that is
not an array, and six more spelled the same predicate as isObject,
isSchemaRecord or isStorageRecord. They now import isRecord from
src/domain/isRecord.ts, whose overloads keep JsonValue narrowing for the
desktop and environment readers. DshCordisPatch's predicate also excludes
Cordis expressions, so it is renamed isPatchRecord.

architecture-guards refuses a new local copy under any name. The seven files
that still hold one are listed and must leave the list when their copy goes.

* fix(guards): count record predicate copies precisely

* test(hopper): retry after confirmed application exit

* fix: reject stale record predicate exceptions

scripts/verify/architecture-guards.mjs

@@ -3,6 +3,7 @@ import { existsSync } from "node:fs";
 import { readFile, readdir, writeFile } from "node:fs/promises";
 import { join, relative, sep } from "node:path";
 import { fileURLToPath } from "node:url";
+import { recordPredicateCounts } from "./record-predicate-guard.mjs";
 import {
   compareCountedBaseline,
   recordLoweredBaseline,
@@ -167,6 +168,43 @@ check(
   ],
 );
 
+// "Non-null object other than an array" has one owner: src/domain/isRecord.ts.
+// A local predicate with that body, under any name, is a copy. The listed files
+// still hold one and may only be removed from the list; a listed file that no
+// longer matches fails so the list shrinks with the code.
+const RECORD_PREDICATE_COPIES = [
+  // Exported under a module-specific name; importers still use that name.
+  "src/browser/history/CaptureRedaction.ts",
+  "src/contracts/compactJsonSchema.ts",
+  "src/domain/analysisView/environmentStateRules.ts",
+  // Owned by the advertised-schema workstream.
+  "src/contracts/inputSchemaPresentation.ts",
+  // Narrows a protocol-specific parameter type, not unknown.
+  "src/browser/execution/CdpRuntimeInitiator.ts",
+  // Named `object`, which also spells the typeof result in these files.
+  "src/pcap/PcapDnsWire.ts",
+  "src/pcap/PcapOutput.ts",
+];
+const mismatchedRecordCopies = files.filter(({ path, content }) => {
+  if (path === "src/domain/isRecord.ts") return false;
+  const { named, bodies } = recordPredicateCounts(content);
+  return (
+    named !== 0 || bodies !== (RECORD_PREDICATE_COPIES.includes(path) ? 1 : 0)
+  );
+});
+const pathsWithRecordCopies = new Set(files.map(({ path }) => path));
+const missingRecordCopies = RECORD_PREDICATE_COPIES.filter(
+  (path) => !pathsWithRecordCopies.has(path),
+);
+if (mismatchedRecordCopies.length > 0)
+  failures.push(
+    `local non-array record predicate count changed (import isRecord and update the baseline):\n${mismatchedRecordCopies.map(({ path }) => `  ${path}`).join("\n")}`,
+  );
+if (missingRecordCopies.length > 0)
+  failures.push(
+    `record predicate baseline references missing files; remove those entries:\n${missingRecordCopies.map((path) => `  ${path}`).join("\n")}`,
+  );
+
 // Node clamps a timer delay above the signed 32-bit bound to 1 ms. Durations
 // use MAX_NODE_TIMER_DELAY_MS or timerDurationMsSchema from their one owner.
 // The allowed files bound signed 32-bit integers that are not timer delays.

scripts/verify/record-predicate-guard.d.mts

@@ -0,0 +1,4 @@
+export function recordPredicateCounts(content: string): {
+  named: number;
+  bodies: number;
+};

scripts/verify/record-predicate-guard.mjs

@@ -0,0 +1,13 @@
+/** Count declarations named isRecord and declarations with the shared predicate. */
+export const recordPredicateCounts = (content) => {
+  const arrow =
+    /\bconst\s+[\w$]+\s*=\s*\(\s*([\w$]+)[^)]*\)\s*(?::[^=]+)?=>\s*typeof\s+\1\s*===\s*["']object["']\s*&&\s*\1\s*!==\s*null\s*&&\s*!Array\.isArray\(\1\)\s*(?=;|\})/gu;
+  const declaration =
+    /\bfunction\s+[\w$]+\s*\(\s*([\w$]+)[^)]*\)\s*(?::[^{]+)?\{\s*return\s+typeof\s+\1\s*===\s*["']object["']\s*&&\s*\1\s*!==\s*null\s*&&\s*!Array\.isArray\(\1\)\s*(?=;|\})/gu;
+  return {
+    named: [...content.matchAll(/\b(?:const|function)\s+isRecord\b/gu)].length,
+    bodies:
+      [...content.matchAll(arrow)].length +
+      [...content.matchAll(declaration)].length,
+  };
+};

src/application/ClientConfigurationFiles.ts

@@ -14,6 +14,7 @@ import type { ArtifactResourceScope } from "../artifacts/ArtifactResourceScope.j
 import type { ConfigurationError } from "../domain/configurationErrors.js";
 import { mergeEnvironmentOverrides } from "../process/snapshotEnvironment.js";
 import { PRODUCT_IDENTITY } from "../identity.js";
+import { isRecord } from "../domain/isRecord.js";
 
 /** A parsed layer retains its path so rereading the write target replaces only that layer. */
 export interface ClientConfigurationSource extends ClientConfigurationDocument {
@@ -167,7 +168,7 @@ export const readClientConfigurationFiles = async (
 
 /** OpenCode merges server objects in file order, replacing arrays and scalar values. */
 const mergeConfigurationValue = (previous: unknown, next: unknown): unknown => {
-  if (!isObject(previous) || !isObject(next)) return next;
+  if (!isRecord(previous) || !isRecord(next)) return next;
   return Object.fromEntries(
     [...new Set([...Object.keys(previous), ...Object.keys(next)])].map(
       (key) => [
@@ -179,8 +180,6 @@ const mergeConfigurationValue = (previous: unknown, next: unknown): unknown => {
     ),
   );
 };
-const isObject = (value: unknown): value is Record<string, unknown> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
 
 /** Native OpenCode dialect applies across all selected configuration layers. */
 export const clientWriteDialect = (
@@ -260,12 +259,12 @@ export const mergeClientConfigurationDocuments = (
       const key = document.environmentKey;
       if (
         name === PRODUCT_IDENTITY.mcpServerKey &&
-        isObject(merged) &&
-        isObject(merged[key])
+        isRecord(merged) &&
+        isRecord(merged[key])
       ) {
         const before =
-          isObject(previous) && isObject(previous[key]) ? previous[key] : {};
-        const after = isObject(next) && isObject(next[key]) ? next[key] : {};
+          isRecord(previous) && isRecord(previous[key]) ? previous[key] : {};
+        const after = isRecord(next) && isRecord(next[key]) ? next[key] : {};
         servers[name] = {
           ...merged,
           [key]: mergeEnvironmentOverrides(before, after, platform),

src/application/DshCordisPatch.ts

@@ -11,7 +11,7 @@ export const DSH_ENTRY_ID = "rea-mcp";
 export const DSH_CLIENT_PACKAGE = "@deepseek-ai/dsh-mcp-client";
 const LAUNCHER_KEYS = new Set(["serverName", "transport", "command", "args"]);
 const SELECTOR_KEYS = new Set(["id", "name"]);
-const isRecord = (value: unknown): value is Record<string, unknown> =>
+const isPatchRecord = (value: unknown): value is Record<string, unknown> =>
   typeof value === "object" &&
   value !== null &&
   !Array.isArray(value) &&
@@ -133,7 +133,8 @@ export class DshCordisDocument {
             : undefined;
     const config = this.#field("config");
     // Ownership survives malformed config so uninstall can remove the source row.
-    this.config = insertions === 0 ? undefined : isRecord(config) ? config : {};
+    this.config =
+      insertions === 0 ? undefined : isPatchRecord(config) ? config : {};
   }
 
   #map(node: unknown): YAMLMap<unknown, unknown> | undefined {
@@ -209,7 +210,7 @@ export class DshCordisDocument {
           },
         ),
       );
-    if (config !== undefined && !isRecord(config))
+    if (config !== undefined && !isPatchRecord(config))
       return err(
         new ConfigurationError("Cordis REA config must be a mapping", {
           settings: [
@@ -221,7 +222,7 @@ export class DshCordisDocument {
         }),
       );
     const raw = this.config?.env;
-    if (raw !== undefined && !isRecord(raw))
+    if (raw !== undefined && !isPatchRecord(raw))
       return err(
         new ConfigurationError("Cordis server environment must be a mapping"),
       );
@@ -268,7 +269,7 @@ export class DshCordisDocument {
     const environment = this.environment(overrides);
     if (!environment.ok) return environment;
     const env = mergeEnvironmentOverrides<unknown>(
-      isRecord(this.config?.env) ? this.config.env : {},
+      isPatchRecord(this.config?.env) ? this.config.env : {},
       overrides,
     );
     const desired = { ...this.config, ...dshClientRegistrationEntry(command) };
@@ -378,7 +379,7 @@ export class DshCordisDocument {
       this.#yaml.setValue(config, key, desired[key]);
     const env = this.#map(this.#yaml.field(sourceConfig, "env"));
     const desiredEnv = desired.env;
-    if (isRecord(desiredEnv)) {
+    if (isPatchRecord(desiredEnv)) {
       const nextEnv =
         env === undefined
           ? this.#yaml.document.createNode({})

src/application/desktop/DesktopApplicationExport.ts

@@ -78,6 +78,7 @@ import {
   type TaskSummary,
 } from "./DesktopTaskExport.js";
 import { taskReads } from "./DesktopExportReaders.js";
+import { isRecord } from "../../domain/isRecord.js";
 
 const OPERATION = "export_desktop_application";
 /** Largest seed file the export copies; the state view reads only 64 MiB. */
@@ -136,11 +137,6 @@ export interface DesktopExportResult {
   readonly consented_files: readonly string[];
 }
 
-const isRecord = (
-  value: JsonValue | null | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** The application's dconf groups at the seed, as a dconf key file with the identity scrubbed from its strings. */
 const seedDconf = (
   state: DesktopApplicationState,

src/application/environment/environmentCompareDiff.ts

@@ -23,6 +23,7 @@ import {
   translateValue,
   type IdMap,
 } from "./environmentCompareIds.js";
+import { isRecord } from "../../domain/isRecord.js";
 
 export const DIFFERENCE_CATEGORIES = [
   "status",
@@ -67,9 +68,6 @@ const TIME_FIELD_CAMEL =
   /(?:At|Time|Date|Timestamp|Created|Updated|Modified)$/u;
 const ID_LIST_FIELD = /^(ids|uuids|guids)$/u;
 
-const isObject = (value: JsonValue | undefined): value is JsonObject =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 const shown = (value: JsonValue | undefined): string => {
   const text = value === undefined ? "<absent>" : JSON.stringify(value);
   return text.length > VALUE_CHARS ? `${text.slice(0, VALUE_CHARS)}…` : text;
@@ -517,7 +515,7 @@ class Differ {
   ): void {
     if (Array.isArray(live) && Array.isArray(env))
       this.array(live, env, pointer, at.clockKey ?? at.key, generation);
-    else if (isObject(live) && isObject(env))
+    else if (isRecord(live) && isRecord(env))
       this.object(
         live,
         env,
@@ -528,8 +526,8 @@ class Differ {
     else if (
       Array.isArray(live) ||
       Array.isArray(env) ||
-      isObject(live) ||
-      isObject(env)
+      isRecord(live) ||
+      isRecord(env)
     )
       this.add({
         category: "value",

src/application/environment/environmentCompareIds.ts

@@ -4,13 +4,11 @@ import type { BodyAddress } from "../../domain/analysisView/environmentStateWrit
 import { isUuid } from "../../domain/analysisView/environmentStateWriteValues.js";
 import type { JsonValue } from "../../domain/jsonValue.js";
 import type { ProbeToolCall } from "./environmentCompareMatch.js";
+import { isRecord } from "../../domain/isRecord.js";
 
 /** Field names that hold an identifier: `id`, `uuid`, `guid`, or names ending in `id` or `_id`. */
 export const ID_FIELD = /^(id|uuid|guid)$|(_id|Id|ID|_uuid|Uuid)$/u;
 
-const isObject = (value: JsonValue | undefined): value is JsonObject =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 const isScalarId = (value: JsonValue | undefined): value is string | number =>
   (typeof value === "string" && value !== "") ||
   (typeof value === "number" && Number.isFinite(value));
@@ -179,7 +177,7 @@ const pairing = (
     ),
     by,
   });
-  if (!live.every(isObject) || !env.every(isObject))
+  if (!live.every(isRecord) || !env.every(isRecord))
     return byPosition("position");
   const liveItems = live as readonly JsonObject[];
   const envItems = env as readonly JsonObject[];
@@ -218,7 +216,7 @@ const keyedByIds = (
     ([key, value]) =>
       /^\d+$/u.test(key) ||
       isUuid(key) ||
-      (isObject(value) &&
+      (isRecord(value) &&
         Object.entries(value).some(
           ([field, held]) =>
             IDENTITY_FIELD.test(field) &&
@@ -237,7 +235,7 @@ export const keyedByLearnedIds = (
   if (!entries.some(([key]) => map.hasLive(key))) return false;
   return entries.some(([key]) => Object.hasOwn(env, key))
     ? keyedByIds(entries)
-    : entries.every(([, value]) => isObject(value)) || keyedByIds(entries);
+    : entries.every(([, value]) => isRecord(value)) || keyedByIds(entries);
 };
 
 /**
@@ -258,8 +256,8 @@ const learnKeyedEntries = (
     liveEntries.length === 0 ||
     envEntries.length === 0 ||
     shared === liveEntries.length ||
-    !liveEntries.every(([, value]) => isObject(value)) ||
-    !envEntries.every(([, value]) => isObject(value))
+    !liveEntries.every(([, value]) => isRecord(value)) ||
+    !envEntries.every(([, value]) => isRecord(value))
   )
     return false;
   const paired = pairing(
@@ -340,7 +338,7 @@ const learnAt = (
       });
     return;
   }
-  if (!isObject(live) || !isObject(env)) {
+  if (!isRecord(live) || !isRecord(env)) {
     if (
       context.identity &&
       place.at === context.entityAt &&
@@ -423,7 +421,7 @@ const inEnvTerms = (
 export const translateValue = (value: JsonValue, map: IdMap): JsonValue => {
   if (Array.isArray(value))
     return value.map((item) => translateValue(item, map));
-  if (isObject(value))
+  if (isRecord(value))
     return Object.fromEntries(
       Object.entries(value).map(([key, item]) => [
         key,
@@ -455,7 +453,7 @@ const translateBulkBody = (
       ? value.map((entry) =>
           address.by === "ids"
             ? id(entry)
-            : isObject(entry) && Object.hasOwn(entry, idField)
+            : isRecord(entry) && Object.hasOwn(entry, idField)
               ? {
                   ...(translateValue(entry, map) as JsonObject),
                   [idField]: id(entry[idField]!),
@@ -464,7 +462,7 @@ const translateBulkBody = (
         )
       : translateValue(value, map);
   if (address.member === null) return entries(body);
-  return isObject(body)
+  return isRecord(body)
     ? Object.fromEntries(
         Object.entries(body).map(([key, value]) => [
           key,

src/browser/CdpCaptureValues.ts

@@ -4,12 +4,10 @@ import type { BrowserObservationOperation } from "../domain/browserObservationEr
 import { sanitizeBrowserUrl } from "../domain/browserObservation.js";
 import { createWebTextArtifact } from "../domain/webContentArtifact.js";
 import { err, ok, type Result } from "../domain/result.js";
+import { isRecord } from "../domain/isRecord.js";
 
 export type UnknownRecord = Readonly<Record<string, unknown>>;
 
-const isRecord = (value: unknown): value is UnknownRecord =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 export const recordValue = (value: unknown): UnknownRecord | undefined =>
   isRecord(value) ? value : undefined;
 

src/browser/CdpConnection.ts

@@ -23,6 +23,7 @@ import {
 } from "../domain/browserDeadline.js";
 import { safeParseJson } from "../domain/safeJson.js";
 import { WEB_RUNTIME_LIMITS } from "../domain/webRuntime.js";
+import { isRecord } from "../domain/isRecord.js";
 
 // ws currently stores maxPayload as a signed 32-bit integer. Larger values can
 // wrap to a negative number, which disables its limit check.
@@ -625,9 +626,6 @@ const rawBytes = (data: RawData): Buffer =>
       ? data
       : Buffer.from(data);
 
-const isRecord = (value: unknown): value is Record<string, unknown> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 const waitForOpen = async (
   socket: WebSocket,
   operation: BrowserObservationOperation,

src/browser/ElectronFileScope.ts

@@ -31,6 +31,7 @@ import {
   DEFAULT_ASAR_HEADER_ADMISSION,
   type AsarHeaderAdmission,
 } from "../config/asarHeaderAdmission.js";
+import { isRecord } from "../domain/isRecord.js";
 
 type ElectronFileOperation =
   | "inspect_electron_page"
@@ -374,9 +375,6 @@ const isAsarRegularFile = (
   );
 };
 
-const isRecord = (value: unknown): value is Readonly<Record<string, unknown>> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 const throwIfAborted = (signal?: AbortSignal): void => {
   assertArtifactReadActive(signal);
 };

src/browser/protocol/CdpFrameTree.ts

@@ -1,4 +1,5 @@
 import { z } from "zod";
+import { isRecord } from "../../domain/isRecord.js";
 
 import {
   observeCdpFrameUrl,
@@ -59,9 +60,6 @@ interface MutableNode extends CdpFrameTreeNode {
   readonly children: CdpFrameTreeNode[];
 }
 
-const isRecord = (value: unknown): value is UnknownRecord =>
-  recordValue(value) !== undefined;
-
 const treeRecord = z.custom<UnknownRecord>(isRecord, {
   message: "Expected a frame tree object.",
 });

src/cli/jsonLines.ts

@@ -4,6 +4,7 @@ import { err, ok, type Result } from "../domain/result.js";
 
 import { AnalysisInputError } from "../domain/analysisErrorCore.js";
 import { jsonParts } from "../domain/jsonSerialization.js";
+import { isRecord } from "../domain/isRecord.js";
 
 /** Reserved control-record marker, not an advertised external JSON Schema. */
 export const JSON_LINES_PROTOCOL = "jsonl/v1";
@@ -56,9 +57,6 @@ export interface JsonLinesPlan extends Collection {
   readonly filter: string | undefined;
 }
 
-const isRecord = (value: unknown): value is Record<string, unknown> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 const atPath = (value: unknown, path: readonly string[]): unknown => {
   for (const key of path) {
     if (!isRecord(value) || !Object.hasOwn(value, key)) return undefined;

src/cliLogging.ts

@@ -8,9 +8,7 @@ import {
   type AnalysisErrorProjection,
 } from "./domain/analysisErrorProjection.js";
 import type { Logger } from "pino";
-
-const isRecord = (value: unknown): value is Readonly<Record<string, unknown>> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
+import { isRecord } from "./domain/isRecord.js";
 
 type CliFailureIdentity = Pick<
   AnalysisErrorProjection,

src/contracts/advertisedDialect.ts

@@ -3,6 +3,7 @@ import {
   schemaDepth,
   serializedBytes,
 } from "./compactJsonSchema.js";
+import { isRecord } from "../domain/isRecord.js";
 import {
   schemaArrays,
   schemaChildren,
@@ -335,9 +336,6 @@ export const portablePatternViolations = (
 
 type SchemaKind = "input" | "output";
 
-const isRecord = (value: unknown): value is Readonly<Record<string, unknown>> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** Visit every schema position; instance literals stay opaque. */
 const visitSchemas = (
   schema: unknown,

src/contracts/toolSchemaMetadata.ts

@@ -15,6 +15,7 @@ import {
 } from "./jsonSchemaKeywords.js";
 import { digestCanonicalValue } from "../domain/canonicalDigest.js";
 import { getEvidenceInputContract } from "../domain/evidenceInputContract.js";
+import { isRecord } from "../domain/isRecord.js";
 
 const PROPERTY_DESCRIPTIONS: Readonly<Record<string, string>> = {
   addresses: "Ordered provider-normalized procedure addresses to analyze.",
@@ -171,9 +172,9 @@ export const transformAdvertisedInputJsonSchema = <Schema>(
   transform: (projected: Record<string, unknown>) => Record<string, unknown>,
 ): Schema => {
   const standard = Reflect.get(schema as object, "~standard");
-  if (!isSchemaRecord(standard)) return schema;
+  if (!isRecord(standard)) return schema;
   const jsonSchema = Reflect.get(standard, "jsonSchema");
-  if (!isSchemaRecord(jsonSchema)) return schema;
+  if (!isRecord(jsonSchema)) return schema;
   const project = Reflect.get(jsonSchema, "input");
   if (typeof project !== "function") return schema;
   const byTarget = new Map<string, Record<string, unknown>>();
@@ -187,11 +188,8 @@ export const transformAdvertisedInputJsonSchema = <Schema>(
       if (cached !== undefined) return cached;
     }
     const projected = (project as (options: unknown) => unknown)(options);
-    const transformed = isSchemaRecord(projected)
-      ? transform(projected)
-      : projected;
-    if (cacheable && isSchemaRecord(transformed))
-      byTarget.set(target, transformed);
+    const transformed = isRecord(projected) ? transform(projected) : projected;
+    if (cacheable && isRecord(transformed)) byTarget.set(target, transformed);
     return transformed;
   };
   return {
@@ -226,7 +224,7 @@ const hasRelativeSchemaReference = (
     if (current === null || typeof current !== "object") continue;
     const { position } = entry;
     const scope =
-      position !== "map" && isSchemaRecord(current)
+      position !== "map" && isRecord(current)
         ? references.enter(current, entry.scope)
         : entry.scope;
     if (scope === undefined) return true;
@@ -322,9 +320,6 @@ const memoizeByTarget = (
   };
 };
 
-const isSchemaRecord = (value: unknown): value is Record<string, unknown> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 const fallbackPropertyDescription = (property: string): string | undefined => {
   const explicit = Object.hasOwn(PROPERTY_DESCRIPTIONS, property)
     ? PROPERTY_DESCRIPTIONS[property]

src/domain/analysisView/environmentStateCounters.ts

@@ -1,11 +1,9 @@
 import { jsonPointerTokens } from "../jsonPointer.js";
 import type { JsonValue } from "../jsonValue.js";
+import { isRecord } from "../isRecord.js";
 
 type JsonObject = { [key: string]: JsonValue };
 
-const isObject = (value: JsonValue | undefined): value is JsonObject =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** A list counter's member names: a top-level member's name not starting with `/`, else a pointer (`/pageInfo/totalRows`, `/~1total`). */
 export const counterPath = (counter: string): string[] =>
   counter.startsWith("/") ? jsonPointerTokens(counter) : [counter];
@@ -17,7 +15,7 @@ export const counterAt = (
 ): JsonValue | undefined =>
   counterPath(counter).reduce<JsonValue | undefined>(
     (value, name) =>
-      isObject(value) && Object.hasOwn(value, name) ? value[name] : undefined,
+      isRecord(value) && Object.hasOwn(value, name) ? value[name] : undefined,
     body,
   );
 
@@ -30,7 +28,7 @@ export const withCounter = (
   const set = (node: JsonValue, path: readonly string[]): JsonValue => {
     const [name, ...rest] = path;
     if (name === undefined) return value;
-    if (!isObject(node) || !Object.hasOwn(node, name)) return node;
+    if (!isRecord(node) || !Object.hasOwn(node, name)) return node;
     return { ...node, [name]: set(node[name]!, rest) };
   };
   return set(body, counterPath(counter));

src/domain/browserScenarioNormalization.ts

@@ -8,6 +8,7 @@ import {
   type BrowserScenarioNormalization,
   type BrowserScenarioNormalizationRule,
 } from "./browserScenarioDiffValues.js";
+import { isRecord } from "./isRecord.js";
 
 /** Canonically order and commit a parsed browser scenario normalization policy. */
 export const commitBrowserScenarioNormalization = (
@@ -78,7 +79,7 @@ export const normalizeScenarioValue = (
 
 /** Compare parsed storage records by their fixed fields without serializing them. */
 const compareStorageEntries = (left: unknown, right: unknown): number => {
-  if (!isStorageRecord(left) || !isStorageRecord(right))
+  if (!isRecord(left) || !isRecord(right))
     return compareUnicodeCodePoints(
       digestCanonicalValue(left, "Browser scenario"),
       digestCanonicalValue(right, "Browser scenario"),
@@ -103,9 +104,6 @@ const compareStorageEntries = (left: unknown, right: unknown): number => {
   return 0;
 };
 
-const isStorageRecord = (value: unknown): value is Record<string, unknown> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 const compareStorageField = (left: unknown, right: unknown): number => {
   if (left === right) return 0;
   if (left === null) return -1;

src/domain/desktop/appTaskChecks.ts

@@ -22,6 +22,7 @@ import {
   zipEntryAt,
   zipLeavesOutAt,
 } from "./zipView.js";
+import { isRecord } from "../isRecord.js";
 
 /** One file as the app's data/get reports it: its view, or why it has none. An absent file has no entry. */
 export interface TaskFileView {
@@ -83,11 +84,6 @@ const undecided = (file: string): Verdict =>
 const notFound = (description: string, cut: boolean): Verdict =>
   cut ? unread(description) : fail(description);
 
-const isRecord = (
-  value: JsonValue | null | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** JSON equality: numbers by value, objects by their keys, arrays in order. */
 export const sameJson = (
   actual: JsonValue | undefined,

src/domain/desktop/appTaskDraft.ts

@@ -35,6 +35,7 @@ import {
 import { diffNamedMembers, diffStateViews } from "./stateChanges.js";
 import { DRAFT_VIEW_CHARS } from "./valueCuts.js";
 import { resolvePointer } from "./viewPointer.js";
+import { isRecord } from "../isRecord.js";
 
 type Version = DesktopStatePath["versions"][number];
 type Suggestion = DesktopTaskCheckInput;
@@ -52,11 +53,6 @@ const versions = (baseline: Version, final: Version) => ({
   final: final.view,
 });
 
-const isRecord = (
-  value: JsonValue | null | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** A JSON value cut to a size an agent can read, and whether anything was cut. */
 const bounded = (
   value: JsonValue | null,

src/domain/desktop/appTaskDraftAdded.ts

@@ -22,6 +22,7 @@ import {
 import { pairMembers } from "./memberPairing.js";
 import { elementText, isXmlElement, resolvePointer } from "./viewPointer.js";
 import { selectorOf } from "./viewSelector.js";
+import { isRecord } from "../isRecord.js";
 
 type Suggestion = DesktopTaskCheckInput;
 
@@ -68,11 +69,6 @@ type Element = Extract<JsonValue, Record<string, JsonValue>> & {
   readonly children: JsonValue[];
 };
 
-const isRecord = (
-  value: JsonValue | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 const attributesOf = (element: Element) =>
   isRecord(element.attributes) ? element.attributes : {};
 

src/domain/desktop/appTaskDraftJson.ts

@@ -31,6 +31,7 @@ const locatePointer = (view: JsonValue | null, pointer: string) =>
 const resolvePointer = (view: JsonValue | null, pointer: string) =>
   resolveView(view, pointer, "json");
 import { selectorOf, spellCondition } from "./viewSelector.js";
+import { isRecord } from "../isRecord.js";
 
 type Suggestion = DesktopTaskCheckInput;
 
@@ -182,11 +183,6 @@ export const ownNamesUnreadOtherwise = (
   return kept;
 };
 
-const isRecord = (
-  value: JsonValue | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** The array a member pointer sits in, when its parent is one in a view. The empty pointer is the view itself, as a file whose top level is an array. */
 const arrayOf = (view: JsonValue | null, pointer: string) => {
   const list = pointer.replace(/\/[^/]+$/u, "");

src/domain/desktop/appTaskDraftNamed.ts

@@ -49,14 +49,10 @@ import {
   valueFormat,
   type CheckTree,
 } from "./appTaskDraftTree.js";
+import { isRecord } from "../isRecord.js";
 
 type Suggestion = DesktopTaskCheckInput;
 
-const isRecord = (
-  value: JsonValue | null | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** Pointers without a listed descendant: a container listed with its members is suggested through them. */
 export const innermost = (pointers: readonly string[]): readonly string[] =>
   pointers.filter(

src/domain/desktop/appTaskDraftNoise.ts

@@ -13,6 +13,7 @@ import { idReferencesOf, mirrorsOf } from "./appTaskDraftMirrors.js";
 import { isPositionalKey, positionalKeys } from "./positionalKeys.js";
 import type { DesktopStateDifference } from "./stateChanges.js";
 import { elementText, isXmlElement, resolvePointer } from "./viewPointer.js";
+import { isRecord } from "../isRecord.js";
 
 /** Why a change is what an app writes as it saves or shows a document, rather than what its user made. */
 export const NOISE_REASONS = [
@@ -138,11 +139,6 @@ type Element = Record<string, JsonValue> & {
   children: JsonValue[];
 };
 
-const isRecord = (
-  value: JsonValue | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** The elements a pointer steps into through `children`, read from the view, outermost first. */
 const elementsAlong = (
   view: JsonValue | null,

src/domain/desktop/appTaskDraftRows.ts

@@ -4,15 +4,11 @@ import { countTaskRows } from "./appTaskChecks.js";
 import type { DesktopStatePath } from "./desktopState.js";
 import { sqliteRowIdentity } from "./stateChanges.js";
 import { appendAll } from "../appendAll.js";
+import { isRecord } from "../isRecord.js";
 
 type Version = DesktopStatePath["versions"][number];
 type Suggestion = DesktopTaskCheckInput;
 
-const isRecord = (
-  value: JsonValue | null | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 interface TableView {
   readonly columns: readonly string[];
   readonly key: readonly string[];

src/domain/desktop/appTaskDraftText.ts

@@ -12,6 +12,7 @@ import { valueEqualsCheck } from "./appTaskDraftScalars.js";
 import { rankAttributes } from "./attributeRank.js";
 import type { DesktopStateDifference } from "./stateChanges.js";
 import { elementText, isXmlElement, resolvePointer } from "./viewPointer.js";
+import { isRecord } from "../isRecord.js";
 
 /** The pointers a diff lists, of every kind. */
 type Listed = Pick<DesktopStateDifference, "added" | "changed" | "removed">;
@@ -79,11 +80,6 @@ const parentBelowRoot = (pointer: string): string | undefined => {
 const namedByAttribute = (pointer: string) =>
   (pointer.split("/").at(-1) ?? "").includes("[@");
 
-const isRecord = (
-  value: JsonValue | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** An element's attributes; none for any other value. */
 const attributesOf = (value: JsonValue | undefined) =>
   isXmlElement(value) && isRecord(value.attributes) ? value.attributes : {};

src/domain/desktop/appTaskDraftTree.ts

@@ -10,11 +10,7 @@ import {
   zipLeavesOutAt,
   zipView,
 } from "./zipView.js";
-
-const isRecord = (
-  value: JsonValue | null | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
+import { isRecord } from "../isRecord.js";
 
 /**
  * The entry a pointer into a zip view goes into, when it has a view and both

src/domain/desktop/appTaskDraftValues.ts

@@ -16,6 +16,7 @@ import { holdsFields, isRecordAt } from "./appTaskDraftText.js";
 import { attributesOf, compactValue, previewWriter } from "./compactValue.js";
 import { pairMembers, pairedAtSeed } from "./memberPairing.js";
 import { isXmlElement, locatePointer, resolvePointer } from "./viewPointer.js";
+import { isRecord } from "../isRecord.js";
 
 /** Why a value's pointer cannot go into a check as it is, or why the value is noise. */
 export const VALUE_NOTES = ["by_position", ...NOISE_REASONS] as const;
@@ -91,11 +92,6 @@ export const VALUE_LIMITS = {
   references: 5,
 } as const;
 
-const isRecord = (
-  value: JsonValue | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** The longest value a reference is resolved from. */
 const MAX_REFERENCE_CHARS = 64;
 

src/domain/desktop/compactValue.ts

@@ -1,10 +1,6 @@
 import type { JsonValue } from "../jsonValue.js";
 import { isXmlElement } from "./viewPointer.js";
-
-const isRecord = (
-  value: JsonValue | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
+import { isRecord } from "../isRecord.js";
 
 export const cut = (text: string, max: number) =>
   text.length > max ? `${text.slice(0, max)}…` : text;

src/domain/desktop/jsonRecordPairing.ts

@@ -6,6 +6,7 @@ import {
   isPlaceholder,
 } from "./attributeRank.js";
 import { MAX_INSIDE_STEPS, spellCondition } from "./viewSelector.js";
+import { isRecord } from "../isRecord.js";
 
 /** A field naming a JSON record, as TreeLine's `uid`: `id`, `uid`, `uuid`, `guid`, `key`, or a name ending in `_id`, `-id` or `Id`. */
 const ID_FIELD = /^(?:_?id|uid|uuid|guid|key)$|[_-]id$|[a-z]Id$/u;
@@ -23,11 +24,6 @@ const MAX_NAME = 64;
 /** The most kind fields and paths a version's records are counted by, each a pass over them, so odd records cost no more. */
 const MAX_TALLIES = 64;
 
-const isRecord = (
-  value: JsonValue | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** Whether every member holds a string at a key a selector can carry, each its own. */
 const namesEach = (members: readonly JsonValue[], key: string) => {
   const values = members.map((member) =>

src/domain/desktop/memberPairing.ts

@@ -28,11 +28,7 @@ import {
 import { pairRecordsById } from "./jsonRecordPairing.js";
 import { resolvePointer } from "./viewPointer.js";
 import { selectorOf } from "./viewSelector.js";
-
-const isRecord = (
-  value: JsonValue | null | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
+import { isRecord } from "../isRecord.js";
 
 const own = (record: Record<string, JsonValue>, key: string) =>
   Object.hasOwn(record, key) ? record[key] : undefined;

src/domain/desktop/positionalKeys.ts

@@ -1,10 +1,6 @@
 import type { JsonValue } from "../jsonValue.js";
 import { isIdentifyingAttribute } from "./attributeRank.js";
-
-const isRecord = (
-  value: JsonValue | null | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
+import { isRecord } from "../isRecord.js";
 
 /** An identifier of the members with one tag, as `tag` NUL `key`. */
 const tagKey = (tag: string, key: string) => `${tag}\u0000${key}`;

src/domain/desktop/seedScrub.ts

@@ -16,6 +16,7 @@ import {
   isTextualFormat,
   textSyntaxFormat,
 } from "./stateFormats.js";
+import { isRecord } from "../isRecord.js";
 
 /** What the export ships for one seed. */
 export interface SeedScrub {
@@ -291,11 +292,6 @@ const scrubGVariant = (
   return { text: scrubbed, decoded: [scrubbed, ...strings].join("\n") };
 };
 
-const isRecord = (
-  value: JsonValue | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /**
  * A dconf view's groups as the key file the computer compiles, each value's
  * strings scrubbed, and whether it still holds the identity, strings decoded.

src/domain/desktop/selectorCandidates.ts

@@ -10,11 +10,7 @@ import {
   rankAttributes,
 } from "./attributeRank.js";
 import { selectorOf, spellCondition, type Condition } from "./viewSelector.js";
-
-const isRecord = (
-  value: JsonValue | null | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
+import { isRecord } from "../isRecord.js";
 
 const own = (record: Record<string, JsonValue>, key: string) =>
   Object.hasOwn(record, key) ? record[key] : undefined;
@@ -94,7 +90,9 @@ const stepTag = (tag: JsonValue | undefined): tag is string =>
 /** The element children of a member, none for any other value. */
 const elementsOf = (member: JsonValue): Record<string, JsonValue>[] => {
   const children = isRecord(member) ? own(member, "children") : undefined;
-  return (Array.isArray(children) ? children : []).filter(isRecord);
+  return (Array.isArray(children) ? children : []).filter(
+    (child): child is Record<string, JsonValue> => isRecord(child),
+  );
 };
 
 /** A child's text a condition could name an element by, and whether the child joins it from elements of its own. */

src/domain/desktop/stateChanges.ts

@@ -4,6 +4,7 @@ import type { DesktopStateFormat } from "./stateFormats.js";
 import { holdsTagOnly, pairMembers } from "./memberPairing.js";
 import { memberLookup } from "./viewPointer.js";
 import { zipEntryAt, zipLeavesOut } from "./zipView.js";
+import { isRecord } from "../isRecord.js";
 
 const MAX_LISTED = 100;
 
@@ -20,11 +21,6 @@ export interface DesktopStateDifference {
   readonly complete: boolean;
 }
 
-const isRecord = (
-  value: JsonValue | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** Longest JSON pointer listed; a longer one is only counted, so deep paths never fill the lists. */
 const MAX_LISTED_POINTER = 4096;
 

src/domain/desktop/viewPointer.ts

@@ -7,6 +7,7 @@ import {
   selectorOf,
   type Condition,
 } from "./viewSelector.js";
+import { isRecord } from "../isRecord.js";
 
 /** The arrays a pointer stepped into, each as the pointer to it. */
 interface ArraySteps {
@@ -33,11 +34,6 @@ type Stepped =
 
 const INDEX = /^(?:0|[1-9][0-9]*)$/u;
 
-const isRecord = (
-  value: JsonValue | null | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 const own = (record: Record<string, JsonValue>, key: string) =>
   Object.hasOwn(record, key) ? record[key] : undefined;
 

src/domain/desktop/zipView.ts

@@ -14,6 +14,7 @@ import {
   desktopViewByteDisplay,
   type DesktopViewPolicy,
 } from "./desktopViewPolicy.js";
+import { isRecord } from "../isRecord.js";
 
 /** Why an archive has no view; the exported reader words it the same. */
 export const UNREADABLE_ZIP = "not a readable zip archive";
@@ -111,11 +112,6 @@ export const zipView = (
   truncated: count > entries.length,
 });
 
-const isRecord = (
-  value: JsonValue | null | undefined,
-): value is Record<string, JsonValue> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** Whether an entry's view is missing or holds only part of it. */
 const entryLeavesOut = (entry: JsonValue): boolean =>
   isRecord(entry) &&

src/domain/isRecord.ts

@@ -0,0 +1,13 @@
+import type { JsonValue } from "./jsonValue.js";
+
+/**
+ * Whether a value is a non-null object other than an array. Its keys,
+ * prototype and property values are not inspected.
+ */
+export function isRecord(
+  value: JsonValue | null | undefined,
+): value is { [key: string]: JsonValue };
+export function isRecord(value: unknown): value is Record<string, unknown>;
+export function isRecord(value: unknown): boolean {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}

src/domain/jsonShape.ts

@@ -5,6 +5,7 @@ import { safeParseJson } from "./safeJson.js";
 import { jsonStringByteLength } from "./jsonStringByteLength.js";
 import { jsonValueByteLength } from "./jsonValueByteLength.js";
 import { err, ok, type Result } from "./result.js";
+import { isRecord } from "./isRecord.js";
 
 const jsonValueTypeSchema = z.enum([
   "object",
@@ -278,9 +279,6 @@ export const jsonValueType = (value: unknown): JsonValueType => {
   }
 };
 
-const isRecord = (value: unknown): value is Readonly<Record<string, unknown>> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** Reverse sibling order for the traversal stack; array elements sort first. */
 const orderedChildren = (node: ShapeNode): ShapeNode[] =>
   [...(node.children ?? [])]

src/domain/jsonValue.ts

@@ -1,6 +1,7 @@
 import { types } from "node:util";
 import { z } from "zod";
 import { isImmutableJsonSnapshot } from "./immutableJson.js";
+import { isRecord } from "./isRecord.js";
 
 /** Maximum JSON nesting accepted before recursive result cloning. */
 export const MAX_JSON_DEPTH = 1000;
@@ -14,8 +15,6 @@ export type JsonValue =
   | JsonValue[]
   | { [key: string]: JsonValue };
 
-const isRecord = (value: unknown): value is Record<string, unknown> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
 const immutableValidation = new WeakMap<object, string | undefined>();
 
 /** Validate JSON meaning and nesting without cloning a trusted immutable value. */

src/domain/sourceMapEnvelope.ts

@@ -1,4 +1,5 @@
 import { z } from "zod";
+import { isRecord } from "./isRecord.js";
 
 /** Artifact source declarations do not require generated-position decoding. */
 type SourceMapRecord = Readonly<Record<string, unknown>>;
@@ -53,9 +54,6 @@ export const sourceMapJsonText = (text: string): string => {
   return newline === -1 ? "" : withoutBom.slice(newline);
 };
 
-const isRecord = (value: unknown): value is SourceMapRecord =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** Classify section ownership once; an external URL takes precedence over map. */
 export const classifySourceMapSection = (
   section: unknown,

src/mcpDoctor.ts

@@ -39,6 +39,7 @@ import {
 } from "./mcpStartupPolicy.js";
 import { MCP_DOCTOR_ALIAS, MCP_DOCTOR_OPTIONS } from "./mcpDoctorOptions.js";
 import { OwnedMcpStdioTransport } from "./process/OwnedMcpStdioTransport.js";
+import { isRecord } from "./domain/isRecord.js";
 
 const OUTPUT_FORMATS = CLI_DOCUMENT_OUTPUT_FORMATS;
 type OutputFormat = (typeof OUTPUT_FORMATS)[number];
@@ -672,9 +673,6 @@ const captureStderr = () => {
   };
 };
 
-const isRecord = (value: unknown): value is Readonly<Record<string, unknown>> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 const errorMessage = (cause: unknown): string =>
   cause instanceof Error ? cause.message : String(cause);
 

src/pcap/TsharkJsonPackets.ts

@@ -1,4 +1,5 @@
 import { setImmediate as yieldToEventLoop } from "node:timers/promises";
+import { isRecord } from "../domain/isRecord.js";
 import { err, ok, type Result } from "../domain/result.js";
 
 /**
@@ -31,9 +32,6 @@ export type TsharkJsonFailure =
   | { readonly kind: "json-bytes"; readonly maxBytes: number }
   | { readonly kind: "json-expansion"; readonly maxDecodedBytes: number };
 
-const object = (value: unknown): value is Record<string, unknown> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 const YIELD_INTERVAL = 65_536;
 
 /**
@@ -96,9 +94,9 @@ export const parseTsharkJsonPackets = (
   const packets: TsharkPacketLayers[] = [];
   for (const [index, packet] of decoded.entries()) {
     if (
-      !object(packet) ||
-      !object(packet._source) ||
-      !object(packet._source.layers)
+      !isRecord(packet) ||
+      !isRecord(packet._source) ||
+      !isRecord(packet._source.layers)
     )
       return err({
         kind: "malformed-packet",

src/server/EvidenceMcpServerCore.ts

@@ -122,9 +122,6 @@ const hasAdvertisedInputJsonSchema = (value: unknown): boolean => {
   );
 };
 
-const isRecord = (value: unknown): value is Record<string, unknown> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** Recognize the SDK's argument diagnostic after its wire size is checked. */
 const sdkInputValidationDiagnostic = (
   text: string | undefined,
@@ -289,6 +286,7 @@ export const forgetPendingMcpRequest = (
   pendingCompletions.delete(id);
 };
 import type { PromptCompletionSource } from "./promptCompletion.js";
+import { isRecord } from "../domain/isRecord.js";
 
 /** Standard-schema registration boundary shared with deferred SDK bindings. */
 export interface StandardToolRegistration {

src/server/environment/environmentDataPlane.ts

@@ -11,6 +11,7 @@ import {
   type RpcError,
   type StateIntake,
 } from "./stateIntake.js";
+import { isRecord } from "../../domain/isRecord.js";
 
 /** One data-plane method's outcome; undefined from a method table means the method is not served. */
 export type RpcOutcome =
@@ -24,9 +25,6 @@ export type RpcMethods = (
   signal?: AbortSignal,
 ) => Promise<RpcOutcome | undefined>;
 
-const isRecord = (value: unknown): value is Readonly<Record<string, unknown>> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** The first document problem as `-32602`, located by a JSON pointer into the document. */
 const documentError = (error: AnalysisInputError): RpcError => {
   const issue = error.issues[0];

src/server/environment/serveEnvironment.ts

@@ -62,6 +62,7 @@ import {
   bufferedJsonParts,
   jsonParts,
 } from "../../domain/jsonSerialization.js";
+import { isRecord } from "../../domain/isRecord.js";
 
 /** Where the environment card is served. */
 export const ENVIRONMENT_CARD_PATH = "/.well-known/agent-env.json";
@@ -81,9 +82,6 @@ class EnvironmentMcpServer extends RequestTrackingMcpServer {
   }
 }
 
-const isRecord = (value: unknown): value is Readonly<Record<string, unknown>> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 /** At most this many messages in one data-plane batch; a larger batch is refused whole. */
 const MAX_RPC_BATCH_MESSAGES = 100;
 

src/server/environment/stateIntake.ts

@@ -19,6 +19,7 @@ import {
   RegularFileCleanupFailure,
   withOwnedRegularFile,
 } from "../../filesystem/OwnedRegularFile.js";
+import { isRecord } from "../../domain/isRecord.js";
 
 /** Why a named file or download could not be read, or a call was cancelled: a category naming neither the uri nor the content. */
 export type IntakeFailure =
@@ -125,9 +126,6 @@ const fileFailure = (cause: unknown): IntakeFailure =>
     ? FILE_FAILURES.get(String(cause.code))
     : undefined) ?? "read-failed";
 
-const isRecord = (value: unknown): value is Readonly<Record<string, unknown>> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);
-
 const MAX_INLINE_BASE64_CHARACTERS =
   Math.ceil(STATE_INTAKE_LIMIT_BYTES / 3) * 4;
 

src/server/mcpClientMetadata.ts

@@ -8,6 +8,7 @@ import {
 
 import type { ClientFeatureAvailability } from "../contracts/toolOutputSchemaPrimitives.js";
 import type { ConnectedClientIdentity } from "../serverIdentity.js";
+import { isRecord } from "../domain/isRecord.js";
 
 /** Initialize-scoped client metadata the SDK keeps for a 2025-era connection. */
 export type McpConnectionClientMetadata = Pick<
@@ -69,6 +70,3 @@ const capabilityFeatures = (value: unknown): ClientFeatureAvailability => {
     sampling: capabilities.sampling !== undefined,
   };
 };
-
-const isRecord = (value: unknown): value is Record<string, unknown> =>
-  typeof value === "object" && value !== null && !Array.isArray(value);

tests/evaluation/recordPredicateGuard.test.ts

@@ -0,0 +1,19 @@
+import { expect, it } from "vitest";
+import { recordPredicateCounts } from "../../scripts/verify/record-predicate-guard.mjs";
+
+it("counts both function forms and does not depend on the parameter name", () => {
+  const predicate =
+    'typeof input === "object" && input !== null && !Array.isArray(input)';
+  expect(
+    recordPredicateCounts(`function isObject(input) { return ${predicate}; }`)
+      .bodies,
+  ).toBe(1);
+  expect(
+    recordPredicateCounts(`const isObject = (input) => ${predicate};`).bodies,
+  ).toBe(1);
+  expect(
+    recordPredicateCounts(
+      `const a = (input) => ${predicate}; const b = (input) => ${predicate};`,
+    ).bodies,
+  ).toBe(2);
+});