From 9087f28245f85fb813b8671c3649b6a6377f9a03 Mon Sep 17 00:00:00 2001
From: George Fu <kuhe@users.noreply.github.com>
Date: Thu, 26 Feb 2026 11:16:09 -0500
Subject: [PATCH] test(snapshot-testing): configurable member value overrides

---
 .changeset/plenty-snails-obey.md                   |  5 +++++
 packages/snapshot-testing/src/index.ts             |  1 +
 .../src/structure/createFromSchema.ts              | 14 ++++++++++++--
 3 files changed, 18 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/plenty-snails-obey.md

diff --git a/.changeset/plenty-snails-obey.md b/.changeset/plenty-snails-obey.md
new file mode 100644
index 00000000000..9def7430133
--- /dev/null
+++ b/.changeset/plenty-snails-obey.md
@@ -0,0 +1,5 @@
+---
+"@smithy/snapshot-testing": patch
+---
+
+additional member value overrides for snapshot data generator
diff --git a/packages/snapshot-testing/src/index.ts b/packages/snapshot-testing/src/index.ts
index 59a478d35fa..2e57d80609c 100644
--- a/packages/snapshot-testing/src/index.ts
+++ b/packages/snapshot-testing/src/index.ts
@@ -1 +1,2 @@
 export { SnapshotRunner } from "./SnapshotRunner";
+export { customFields } from "./structure/createFromSchema";
diff --git a/packages/snapshot-testing/src/structure/createFromSchema.ts b/packages/snapshot-testing/src/structure/createFromSchema.ts
index d03d1a64758..4903fbd7af1 100644
--- a/packages/snapshot-testing/src/structure/createFromSchema.ts
+++ b/packages/snapshot-testing/src/structure/createFromSchema.ts
@@ -14,6 +14,10 @@ export function createFromSchema(schema: $SchemaRef, path = ""): any {
   const $ = NormalizedSchema.of(schema);
 
   const memberName = $.isMemberSchema() ? $.getMemberName() : "____";
+  if (customFields[memberName]) {
+    return customFields[memberName];
+  }
+
   const qualifiedName = $.getName(true) ?? "UnknownSchema!";
   path += " -> " + qualifiedName + "$" + memberName;
 
@@ -23,7 +27,7 @@ export function createFromSchema(schema: $SchemaRef, path = ""): any {
     if ($.isIdempotencyToken()) {
       return "00000000-0000-4000-8000-000000000000";
     }
-    return customFields[memberName] ?? "__" + memberName + "__";
+    return "__" + memberName + "__";
   } else if ($.isNumericSchema()) {
     return 0;
   } else if ($.isBigIntegerSchema()) {
@@ -107,7 +111,13 @@ export function createFromSchema(schema: $SchemaRef, path = ""): any {
   return "UNSUPPORTED_SCHEMA_TYPE";
 }
 
-const customFields: Record<string, string> = {
+/**
+ * Overrides the generated values for members with matching names.
+ * @internal
+ */
+export const customFields: Record<string, string> = {
   PredictEndpoint: "https://localhost",
   ChecksumAlgorithm: "CRC64NVME",
+  AccountId: "123456789012",
+  OutpostId: "OutpostId",
 };