Skip content-length header for entries without known length when enableAdditionalHeaders option is enabled

Author: octet-stream

src/FormDataEncoder.test.ts

@@ -399,6 +399,41 @@ test(
   }
 )
 
+test(
+  "Does not imclude Content-Length header with enableAdditionalHeaders "
+    + "option if entry does not have known length",
+
+  async t => {
+    const form = new FormData()
+
+    form.set("stream", {
+      [Symbol.toStringTag]: "File",
+      name: "file.txt",
+      stream() {
+        return Readable.from([Buffer.from("foo")])
+      }
+    })
+
+    const encoder = new FormDataEncoder(form, {
+      enableAdditionalHeaders: true
+    })
+
+    const iterable = readLine(Readable.from(encoder))
+
+    await skip(iterable, 1)
+    const headers: string[] = []
+    for await (const chunk of iterable) {
+      if (chunk === "") {
+        break
+      }
+
+      headers.push(chunk.split(":")[0].toLowerCase())
+    }
+
+    t.false(headers.includes("content-length"))
+  }
+)
+
 test("Yields File's content", async t => {
   const filePath = "license"
   const form = new FormData()

src/FormDataEncoder.ts

@@ -1,3 +1,4 @@
+/* eslint-disable no-restricted-globals */
 import type {LowercaseObjectKeys} from "./util/LowercaseObjectKeys.js"
 import {createBoundary} from "./util/createBoundary.js"
 import {normalizeValue} from "./util/normalizeValue.js"
@@ -207,7 +208,11 @@ export class FormDataEncoder {
     }
 
     const size = isFile(value) ? value.size : value.byteLength
-    if (this.#options.enableAdditionalHeaders === true && size != null) {
+    if (
+      this.#options.enableAdditionalHeaders === true
+        && size != null
+        && !isNaN(size)
+    ) {
       header += `${this.#CRLF}Content-Length: ${
         isFile(value) ? value.size : value.byteLength
       }`
@@ -230,7 +235,7 @@ export class FormDataEncoder {
       const size = isFile(value) ? value.size : value.byteLength
 
       // Return `undefined` if encountered part without known size
-      if (size == null || Number.isNaN(size)) {
+      if (size == null || isNaN(size)) {
         return undefined
       }