From d4775119ff253201967f8486f26a153ce404c435 Mon Sep 17 00:00:00 2001
From: Vansh Dobariya <167301367+VanshBD@users.noreply.github.com>
Date: Mon, 15 Jun 2026 16:49:24 +0530
Subject: [PATCH 1/2] lib: add Math.sumPrecise type definition (ES2026 /
 esnext)

---
 src/compiler/commandLineParser.ts |  1 +
 src/lib/esnext.d.ts               |  1 +
 src/lib/esnext.math.d.ts          | 12 ++++++++++++
 src/lib/libs.json                 |  1 +
 4 files changed, 15 insertions(+)
 create mode 100644 src/lib/esnext.math.d.ts

diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
index c17cc4ef9ca01..a162ea3318a69 100644
--- a/src/compiler/commandLineParser.ts
+++ b/src/compiler/commandLineParser.ts
@@ -256,6 +256,7 @@ const libEntries: [string, string][] = [
     ["esnext.disposable", "lib.esnext.disposable.d.ts"],
     ["esnext.error", "lib.esnext.error.d.ts"],
     ["esnext.intl", "lib.esnext.intl.d.ts"],
+    ["esnext.math", "lib.esnext.math.d.ts"],
     ["esnext.sharedmemory", "lib.esnext.sharedmemory.d.ts"],
     ["esnext.temporal", "lib.esnext.temporal.d.ts"],
     ["esnext.typedarrays", "lib.esnext.typedarrays.d.ts"],
diff --git a/src/lib/esnext.d.ts b/src/lib/esnext.d.ts
index 10d459816a349..acbb46fd351eb 100644
--- a/src/lib/esnext.d.ts
+++ b/src/lib/esnext.d.ts
@@ -9,3 +9,4 @@
 /// <reference lib="esnext.typedarrays" />
 /// <reference lib="esnext.temporal" />
 /// <reference lib="esnext.date" />
+/// <reference lib="esnext.math" />
diff --git a/src/lib/esnext.math.d.ts b/src/lib/esnext.math.d.ts
new file mode 100644
index 0000000000000..c8d05f10c7991
--- /dev/null
+++ b/src/lib/esnext.math.d.ts
@@ -0,0 +1,12 @@
+interface Math {
+    /**
+     * Returns the sum of the values in the iterable using a more precise
+     * summation algorithm than naive floating-point addition.
+     * Returns `-0` if the iterable is empty.
+     * @param numbers An iterable (such as an Array) of numbers.
+     * @throws {TypeError} If `numbers` is not iterable, or if any value
+     * in the iterable is not of type `number`.
+     * @throws {RangeError} If the iterable yields 2^53 or more values.
+     */
+    sumPrecise(numbers: Iterable<number>): number;
+}
diff --git a/src/lib/libs.json b/src/lib/libs.json
index 5bc6a8b57a2c1..2d5e6e2b1abda 100644
--- a/src/lib/libs.json
+++ b/src/lib/libs.json
@@ -92,6 +92,7 @@
         "esnext.decorators",
         "esnext.disposable",
         "esnext.error",
+        "esnext.math",
         "esnext.intl",
         "esnext.sharedmemory",
         "esnext.temporal",

From bbff73934a7454ea6f1ab9fb49c8d926a1a2bdb5 Mon Sep 17 00:00:00 2001
From: Vansh Dobariya <167301367+VanshBD@users.noreply.github.com>
Date: Mon, 15 Jun 2026 17:09:55 +0530
Subject: [PATCH 2/2] lib: fix alphabetical order in libs.json

---
 src/lib/libs.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib/libs.json b/src/lib/libs.json
index 2d5e6e2b1abda..f3128a699aa27 100644
--- a/src/lib/libs.json
+++ b/src/lib/libs.json
@@ -92,8 +92,8 @@
         "esnext.decorators",
         "esnext.disposable",
         "esnext.error",
-        "esnext.math",
         "esnext.intl",
+        "esnext.math",
         "esnext.sharedmemory",
         "esnext.temporal",
         "esnext.typedarrays",