1 files changed, 13 insertions, 3 deletions
diff --git a/js/headers.ts b/js/headers.ts
index 7cc38181f..92077a03f 100644
--- a/js/headers.ts
+++ b/js/headers.ts
@@ -31,10 +31,11 @@ class HeadersBase {
   // https://github.com/bitinn/node-fetch/blob/master/src/headers.js
   // Copyright (c) 2016 David Frank. MIT License.
   private _validateName(name: string) {
-    if (invalidTokenRegex.test(name)) {
+    if (invalidTokenRegex.test(name) || name === "") {
       throw new TypeError(`${name} is not a legal HTTP header name`);
     }
   }
+
   private _validateValue(value: string) {
     if (invalidHeaderCharRegex.test(value)) {
       throw new TypeError(`${value} is not a legal HTTP header value`);
@@ -51,8 +52,17 @@ class HeadersBase {
     } else {
       this[headerMap] = new Map();
       if (Array.isArray(init)) {
-        for (const [rawName, rawValue] of init) {
-          const [name, value] = this._normalizeParams(rawName, rawValue);
+        for (const tuple of init) {
+          // If header does not contain exactly two items,
+          // then throw a TypeError.
+          // ref: https://fetch.spec.whatwg.org/#concept-headers-fill
+          if (tuple.length !== 2) {
+            // tslint:disable:max-line-length
+            // prettier-ignore
+            throw new TypeError("Failed to construct 'Headers'; Each header pair must be an iterable [name, value] tuple");
+          }
+
+          const [name, value] = this._normalizeParams(tuple[0], tuple[1]);
           this._validateName(name);
           this._validateValue(value);
           const existingValue = this[headerMap].get(name);