3 files changed, 34 insertions, 2 deletions
diff --git a/cli/tests/unit/write_file_test.ts b/cli/tests/unit/write_file_test.ts
index 0c3ff491d..78d0f5bad 100644
--- a/cli/tests/unit/write_file_test.ts
+++ b/cli/tests/unit/write_file_test.ts
@@ -393,3 +393,19 @@ function pathExists(path: string | URL) {
     return false;
   }
 }
+
+Deno.test(
+  { permissions: { read: true, write: true } },
+  async function writeFileStream() {
+    const stream = new ReadableStream({
+      pull(controller) {
+        controller.enqueue(new Uint8Array([1]));
+        controller.enqueue(new Uint8Array([2]));
+        controller.close();
+      },
+    });
+    const filename = Deno.makeTempDirSync() + "/test.txt";
+    await Deno.writeFile(filename, stream);
+    assertEquals(Deno.readFileSync(filename), new Uint8Array([1, 2]));
+  },
+);
diff --git a/cli/tests/unit/write_text_file_test.ts b/cli/tests/unit/write_text_file_test.ts
index c83534928..ee9cac177 100644
--- a/cli/tests/unit/write_text_file_test.ts
+++ b/cli/tests/unit/write_text_file_test.ts
@@ -198,3 +198,19 @@ Deno.test(
     assertEquals(Deno.readTextFileSync(filename), "Hello");
   },
 );
+
+Deno.test(
+  { permissions: { read: true, write: true } },
+  async function writeTextFileStream() {
+    const stream = new ReadableStream({
+      pull(controller) {
+        controller.enqueue("Hello");
+        controller.enqueue("World");
+        controller.close();
+      },
+    });
+    const filename = Deno.makeTempDirSync() + "/test.txt";
+    await Deno.writeTextFile(filename, stream);
+    assertEquals(Deno.readTextFileSync(filename), "HelloWorld");
+  },
+);
diff --git a/cli/tsc/dts/lib.deno.ns.d.ts b/cli/tsc/dts/lib.deno.ns.d.ts
index 5941a5d57..3ddd0263b 100644
--- a/cli/tsc/dts/lib.deno.ns.d.ts
+++ b/cli/tsc/dts/lib.deno.ns.d.ts
@@ -3364,7 +3364,7 @@ declare namespace Deno {
    */
   export function writeFile(
     path: string | URL,
-    data: Uint8Array,
+    data: Uint8Array | ReadableStream<Uint8Array>,
     options?: WriteFileOptions,
   ): Promise<void>;
 
@@ -3407,7 +3407,7 @@ declare namespace Deno {
    */
   export function writeTextFile(
     path: string | URL,
-    data: string,
+    data: string | ReadableStream<string>,
     options?: WriteFileOptions,
   ): Promise<void>;