fix(util-body-length-node): support fd.createReadStream (#3385)

Author: trivikr

packages/util-body-length-node/src/calculateBodyLength.spec.ts

@@ -1,4 +1,4 @@
-import { createReadStream, lstatSync } from "fs";
+import { createReadStream, lstatSync, promises } from "fs";
 
 import { calculateBodyLength } from "./calculateBodyLength";
 
@@ -38,17 +38,27 @@ describe(calculateBodyLength.name, () => {
     expect(calculateBodyLength(view)).toEqual(1);
   });
 
-  describe("should handle stream created using fs.createReadStream", () => {
+  describe("fs.ReadStream", () => {
     const fileSize = lstatSync(__filename).size;
 
-    it("when path is a string", () => {
-      const fsReadStream = createReadStream(__filename);
-      expect(calculateBodyLength(fsReadStream)).toEqual(fileSize);
+    describe("should handle stream created using fs.createReadStream", () => {
+      it("when path is a string", () => {
+        const fsReadStream = createReadStream(__filename);
+        expect(calculateBodyLength(fsReadStream)).toEqual(fileSize);
+      });
+
+      it("when path is a Buffer", () => {
+        const fsReadStream = createReadStream(Buffer.from(__filename));
+        expect(calculateBodyLength(fsReadStream)).toEqual(fileSize);
+      });
     });
 
-    it("when path is a Buffer", () => {
-      const fsReadStream = createReadStream(Buffer.from(__filename));
-      expect(calculateBodyLength(fsReadStream)).toEqual(fileSize);
+    it("should handle stream created using fd.createReadStream", async () => {
+      const fd = await promises.open(__filename, "r");
+      if ((fd as any).createReadStream) {
+        const fdReadStream = (fd as any).createReadStream();
+        expect(calculateBodyLength(fdReadStream)).toEqual(fileSize);
+      }
     });
   });
 });

packages/util-body-length-node/src/calculateBodyLength.ts

@@ -1,4 +1,4 @@
-import { lstatSync } from "fs";
+import { fstatSync, lstatSync } from "fs";
 
 export const calculateBodyLength = (body: any): number | undefined => {
   if (!body) {
@@ -14,5 +14,8 @@ export const calculateBodyLength = (body: any): number | undefined => {
   } else if (typeof body.path === "string" || Buffer.isBuffer(body.path)) {
     // handles fs readable streams
     return lstatSync(body.path).size;
+  } else if (typeof body.fd === "number") {
+    // handles fd readable streams
+    return fstatSync(body.fd).size;
   }
 };