From 9b643dfa87c6a13e52b803e29c5b7982b59662bc Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sat, 19 Sep 2026 01:26:35 +0000
Subject: [PATCH 1/2] Initial plan


From b3675cf05ef2ff32825160309e405abfcdf3e212 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sat, 19 Sep 2026 01:38:48 +0000
Subject: [PATCH 2/2] Accept iterable File constructor bits

Co-authored-by: RyanCavanaugh <6685088+RyanCavanaugh@users.noreply.github.com>
---
 tsc/internal/bundled/libs/lib.dom.d.ts          |  2 +-
 tsc/internal/bundled/libs/lib.webworker.d.ts    |  2 +-
 .../fileConstructorIterableFileBits.symbols     |  9 +++++++++
 .../fileConstructorIterableFileBits.types       | 17 +++++++++++++++++
 tsc/testdata/fixtures/lib/dom.generated.d.ts    |  2 +-
 .../compiler/fileConstructorIterableFileBits.ts |  7 +++++++
 6 files changed, 36 insertions(+), 3 deletions(-)
 create mode 100644 tsc/testdata/baselines/reference/compiler/fileConstructorIterableFileBits.symbols
 create mode 100644 tsc/testdata/baselines/reference/compiler/fileConstructorIterableFileBits.types
 create mode 100644 tsc/testdata/tests/cases/compiler/fileConstructorIterableFileBits.ts

diff --git a/tsc/internal/bundled/libs/lib.dom.d.ts b/tsc/internal/bundled/libs/lib.dom.d.ts
index 9e127c3f5a524..ac1c1a2cc6b91 100644
--- a/tsc/internal/bundled/libs/lib.dom.d.ts
+++ b/tsc/internal/bundled/libs/lib.dom.d.ts
@@ -14439,7 +14439,7 @@ interface File extends Blob {
 
 declare var File: {
     prototype: File;
-    new(fileBits: BlobPart[], fileName: string, options?: FilePropertyBag): File;
+    new(fileBits: Iterable<BlobPart>, fileName: string, options?: FilePropertyBag): File;
 };
 
 /**
diff --git a/tsc/internal/bundled/libs/lib.webworker.d.ts b/tsc/internal/bundled/libs/lib.webworker.d.ts
index 45c6a6134821d..21c11b034b93d 100644
--- a/tsc/internal/bundled/libs/lib.webworker.d.ts
+++ b/tsc/internal/bundled/libs/lib.webworker.d.ts
@@ -4680,7 +4680,7 @@ interface File extends Blob {
 
 declare var File: {
     prototype: File;
-    new(fileBits: BlobPart[], fileName: string, options?: FilePropertyBag): File;
+    new(fileBits: Iterable<BlobPart>, fileName: string, options?: FilePropertyBag): File;
 };
 
 /**
diff --git a/tsc/testdata/baselines/reference/compiler/fileConstructorIterableFileBits.symbols b/tsc/testdata/baselines/reference/compiler/fileConstructorIterableFileBits.symbols
new file mode 100644
index 0000000000000..0c68a2aa78245
--- /dev/null
+++ b/tsc/testdata/baselines/reference/compiler/fileConstructorIterableFileBits.symbols
@@ -0,0 +1,9 @@
+//// [tests/cases/compiler/fileConstructorIterableFileBits.ts] ////
+
+=== fileConstructorIterableFileBits.ts ===
+new File((function* () {
+>File : Symbol(File, Decl(lib.dom.d.ts, --, --), Decl(lib.dom.d.ts, --, --))
+
+    yield "a";
+})(), "name");
+
diff --git a/tsc/testdata/baselines/reference/compiler/fileConstructorIterableFileBits.types b/tsc/testdata/baselines/reference/compiler/fileConstructorIterableFileBits.types
new file mode 100644
index 0000000000000..b6d0552b0bb8e
--- /dev/null
+++ b/tsc/testdata/baselines/reference/compiler/fileConstructorIterableFileBits.types
@@ -0,0 +1,17 @@
+//// [tests/cases/compiler/fileConstructorIterableFileBits.ts] ////
+
+=== fileConstructorIterableFileBits.ts ===
+new File((function* () {
+>new File((function* () {    yield "a";})(), "name") : File
+>File : { new (fileBits: Iterable<BlobPart>, fileName: string, options?: FilePropertyBag): File; prototype: File; }
+>(function* () {    yield "a";})() : Generator<string, void, any>
+>(function* () {    yield "a";}) : () => Generator<string, void, any>
+>function* () {    yield "a";} : () => Generator<string, void, any>
+
+    yield "a";
+>yield "a" : any
+>"a" : "a"
+
+})(), "name");
+>"name" : "name"
+
diff --git a/tsc/testdata/fixtures/lib/dom.generated.d.ts b/tsc/testdata/fixtures/lib/dom.generated.d.ts
index d667879250cf4..514d959aaed42 100644
--- a/tsc/testdata/fixtures/lib/dom.generated.d.ts
+++ b/tsc/testdata/fixtures/lib/dom.generated.d.ts
@@ -14423,7 +14423,7 @@ interface File extends Blob {
 
 declare var File: {
     prototype: File;
-    new(fileBits: BlobPart[], fileName: string, options?: FilePropertyBag): File;
+    new(fileBits: Iterable<BlobPart>, fileName: string, options?: FilePropertyBag): File;
 };
 
 /**
diff --git a/tsc/testdata/tests/cases/compiler/fileConstructorIterableFileBits.ts b/tsc/testdata/tests/cases/compiler/fileConstructorIterableFileBits.ts
new file mode 100644
index 0000000000000..f1d6cef4f47d1
--- /dev/null
+++ b/tsc/testdata/tests/cases/compiler/fileConstructorIterableFileBits.ts
@@ -0,0 +1,7 @@
+// @target: es2022
+// @lib: es2022,dom
+// @noEmit: true
+
+new File((function* () {
+    yield "a";
+})(), "name");