From 610d2da7b38ad327d2c28c325b0eb103ef80c6bf Mon Sep 17 00:00:00 2001
From: Ryan Yang <ryan.yang@stellar.org>
Date: Mon, 9 Feb 2026 15:28:35 -0800
Subject: [PATCH 1/4] Add test globals to ESLint configuration

---
 config/eslint.config.cjs | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/config/eslint.config.cjs b/config/eslint.config.cjs
index 48060a321..8eca0ac52 100644
--- a/config/eslint.config.cjs
+++ b/config/eslint.config.cjs
@@ -44,6 +44,19 @@ const javascriptConfig = [
     rules: {
       "no-unused-vars": ["error", { caughtErrors: "none" }]
     }
+  },
+  {
+    name: "test/globals",
+    files: ["test/**/*.js"],
+    languageOptions: {
+      globals: {
+        ...globals.mocha,
+        StellarBase: "readonly",
+        expect: "readonly",
+        chai: "readonly",
+        sinon: "readonly"
+      }
+    }
   }
 ];
 

From d7453c7c62d0e794ce353d317f686115b24ec7ed Mon Sep 17 00:00:00 2001
From: Ryan Yang <ryan.yang@stellar.org>
Date: Mon, 9 Feb 2026 15:31:07 -0800
Subject: [PATCH 2/4] modify tsconfigs for better reviewing experience

---
 tsconfig.base.json | 2 +-
 tsconfig.cjs.json  | 4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/tsconfig.base.json b/tsconfig.base.json
index 78b812a2a..3a57d47d7 100644
--- a/tsconfig.base.json
+++ b/tsconfig.base.json
@@ -19,7 +19,7 @@
     "noUncheckedIndexedAccess": true,
 
     // JavaScript support
-    "allowJs": true,
+    "allowJs": false,
     "checkJs": false,
 
     // Interop constraints
diff --git a/tsconfig.cjs.json b/tsconfig.cjs.json
index 4af0c5479..77eb6657b 100644
--- a/tsconfig.cjs.json
+++ b/tsconfig.cjs.json
@@ -10,6 +10,8 @@
     "rootDir": "./src",
     "module": "commonjs",
     "moduleResolution": "node10",
-    "esModuleInterop": true
+    "esModuleInterop": true,
+    "declaration": true,
+    "declarationDir": "./type_validation"
   }
 }

From 21f1d4ed218717d23bd09fce48e40dc2c4b85112 Mon Sep 17 00:00:00 2001
From: Ryan Yang <ryan.yang@stellar.org>
Date: Mon, 9 Feb 2026 15:32:40 -0800
Subject: [PATCH 3/4] migrate util/checksum.js and add typescript testing

---
 src/util/{checksum.js => checksum.ts} |  5 ++-
 test/unit/util/checksum.test.ts       | 44 +++++++++++++++++++++++++++
 type_validation/util/checksum.d.ts    |  1 +
 3 files changed, 49 insertions(+), 1 deletion(-)
 rename src/util/{checksum.js => checksum.ts} (73%)
 create mode 100644 test/unit/util/checksum.test.ts
 create mode 100644 type_validation/util/checksum.d.ts

diff --git a/src/util/checksum.js b/src/util/checksum.ts
similarity index 73%
rename from src/util/checksum.js
rename to src/util/checksum.ts
index 4358eb761..8b8d71e35 100644
--- a/src/util/checksum.js
+++ b/src/util/checksum.ts
@@ -1,4 +1,7 @@
-export function verifyChecksum(expected, actual) {
+export function verifyChecksum(
+  expected: Uint8Array,
+  actual: Uint8Array
+): boolean {
   if (expected.length !== actual.length) {
     return false;
   }
diff --git a/test/unit/util/checksum.test.ts b/test/unit/util/checksum.test.ts
new file mode 100644
index 000000000..392e8b984
--- /dev/null
+++ b/test/unit/util/checksum.test.ts
@@ -0,0 +1,44 @@
+import { describe, it, expect } from "vitest";
+import { verifyChecksum } from "../../../src/util/checksum";
+
+describe("verifyChecksum", () => {
+  it("returns true for identical arrays", () => {
+    const a = new Uint8Array([1, 2, 3]);
+    const b = new Uint8Array([1, 2, 3]);
+    expect(verifyChecksum(a, b)).toBe(true);
+  });
+
+  it("returns false for different contents", () => {
+    const a = new Uint8Array([1, 2, 3]);
+    const b = new Uint8Array([1, 2, 4]);
+    expect(verifyChecksum(a, b)).toBe(false);
+  });
+
+  it("returns false for different lengths", () => {
+    const a = new Uint8Array([1, 2, 3]);
+    const b = new Uint8Array([1, 2]);
+    expect(verifyChecksum(a, b)).toBe(false);
+  });
+
+  it("returns true for two empty arrays", () => {
+    expect(verifyChecksum(new Uint8Array([]), new Uint8Array([]))).toBe(true);
+  });
+
+  it("returns true for single matching byte", () => {
+    expect(verifyChecksum(new Uint8Array([0xff]), new Uint8Array([0xff]))).toBe(
+      true
+    );
+  });
+
+  it("returns false when first byte differs", () => {
+    const a = new Uint8Array([0, 2, 3]);
+    const b = new Uint8Array([1, 2, 3]);
+    expect(verifyChecksum(a, b)).toBe(false);
+  });
+
+  it("returns false when last byte differs", () => {
+    const a = new Uint8Array([1, 2, 3]);
+    const b = new Uint8Array([1, 2, 0]);
+    expect(verifyChecksum(a, b)).toBe(false);
+  });
+});
diff --git a/type_validation/util/checksum.d.ts b/type_validation/util/checksum.d.ts
new file mode 100644
index 000000000..935cb048d
--- /dev/null
+++ b/type_validation/util/checksum.d.ts
@@ -0,0 +1 @@
+export declare function verifyChecksum(expected: Uint8Array, actual: Uint8Array): boolean;

From 062619ca9a36f16c10779cce1604fb1adf4c35a1 Mon Sep 17 00:00:00 2001
From: Ryan Yang <ryan.yang@stellar.org>
Date: Mon, 9 Feb 2026 15:33:00 -0800
Subject: [PATCH 4/4] fix lint warnings

---
 src/operation.js              | 2 --
 src/operations/set_options.js | 2 --
 2 files changed, 4 deletions(-)

diff --git a/src/operation.js b/src/operation.js
index eb85aaa5e..5b4162dda 100644
--- a/src/operation.js
+++ b/src/operation.js
@@ -1,5 +1,3 @@
-/* eslint-disable no-bitwise */
-
 import { Hyper } from "@stellar/js-xdr";
 import BigNumber from "./util/bignumber";
 import { trimEnd } from "./util/util";
diff --git a/src/operations/set_options.js b/src/operations/set_options.js
index 8cae8e49c..57e6ed857 100644
--- a/src/operations/set_options.js
+++ b/src/operations/set_options.js
@@ -1,5 +1,3 @@
-/* eslint-disable no-param-reassign */
-
 import xdr from "../xdr";
 import { Keypair } from "../keypair";
 import { StrKey } from "../strkey";