1 files changed, 139 insertions, 0 deletions
diff --git a/cli/js/headers.ts b/cli/js/headers.ts
new file mode 100644
index 000000000..dc0de54dd
--- /dev/null
+++ b/cli/js/headers.ts
@@ -0,0 +1,139 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+import * as domTypes from "./dom_types.ts";
+import { DomIterableMixin } from "./mixins/dom_iterable.ts";
+import { requiredArguments } from "./util.ts";
+
+// From node-fetch
+// Copyright (c) 2016 David Frank. MIT License.
+const invalidTokenRegex = /[^\^_`a-zA-Z\-0-9!#$%&'*+.|~]/;
+const invalidHeaderCharRegex = /[^\t\x20-\x7e\x80-\xff]/;
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+function isHeaders(value: any): value is domTypes.Headers {
+  // eslint-disable-next-line @typescript-eslint/no-use-before-define
+  return value instanceof Headers;
+}
+
+const headerMap = Symbol("header map");
+
+// ref: https://fetch.spec.whatwg.org/#dom-headers
+class HeadersBase {
+  private [headerMap]: Map<string, string>;
+  // TODO: headerGuard? Investigate if it is needed
+  // node-fetch did not implement this but it is in the spec
+
+  private _normalizeParams(name: string, value?: string): string[] {
+    name = String(name).toLowerCase();
+    value = String(value).trim();
+    return [name, value];
+  }
+
+  // The following name/value validations are copied from
+  // https://github.com/bitinn/node-fetch/blob/master/src/headers.js
+  // Copyright (c) 2016 David Frank. MIT License.
+  private _validateName(name: string): void {
+    if (invalidTokenRegex.test(name) || name === "") {
+      throw new TypeError(`${name} is not a legal HTTP header name`);
+    }
+  }
+
+  private _validateValue(value: string): void {
+    if (invalidHeaderCharRegex.test(value)) {
+      throw new TypeError(`${value} is not a legal HTTP header value`);
+    }
+  }
+
+  constructor(init?: domTypes.HeadersInit) {
+    if (init === null) {
+      throw new TypeError(
+        "Failed to construct 'Headers'; The provided value was not valid"
+      );
+    } else if (isHeaders(init)) {
+      this[headerMap] = new Map(init);
+    } else {
+      this[headerMap] = new Map();
+      if (Array.isArray(init)) {
+        for (const tuple of init) {
+          // If header does not contain exactly two items,
+          // then throw a TypeError.
+          // ref: https://fetch.spec.whatwg.org/#concept-headers-fill
+          requiredArguments(
+            "Headers.constructor tuple array argument",
+            tuple.length,
+            2
+          );
+
+          const [name, value] = this._normalizeParams(tuple[0], tuple[1]);
+          this._validateName(name);
+          this._validateValue(value);
+          const existingValue = this[headerMap].get(name);
+          this[headerMap].set(
+            name,
+            existingValue ? `${existingValue}, ${value}` : value
+          );
+        }
+      } else if (init) {
+        const names = Object.keys(init);
+        for (const rawName of names) {
+          const rawValue = init[rawName];
+          const [name, value] = this._normalizeParams(rawName, rawValue);
+          this._validateName(name);
+          this._validateValue(value);
+          this[headerMap].set(name, value);
+        }
+      }
+    }
+  }
+
+  // ref: https://fetch.spec.whatwg.org/#concept-headers-append
+  append(name: string, value: string): void {
+    requiredArguments("Headers.append", arguments.length, 2);
+    const [newname, newvalue] = this._normalizeParams(name, value);
+    this._validateName(newname);
+    this._validateValue(newvalue);
+    const v = this[headerMap].get(newname);
+    const str = v ? `${v}, ${newvalue}` : newvalue;
+    this[headerMap].set(newname, str);
+  }
+
+  delete(name: string): void {
+    requiredArguments("Headers.delete", arguments.length, 1);
+    const [newname] = this._normalizeParams(name);
+    this._validateName(newname);
+    this[headerMap].delete(newname);
+  }
+
+  get(name: string): string | null {
+    requiredArguments("Headers.get", arguments.length, 1);
+    const [newname] = this._normalizeParams(name);
+    this._validateName(newname);
+    const value = this[headerMap].get(newname);
+    return value || null;
+  }
+
+  has(name: string): boolean {
+    requiredArguments("Headers.has", arguments.length, 1);
+    const [newname] = this._normalizeParams(name);
+    this._validateName(newname);
+    return this[headerMap].has(newname);
+  }
+
+  set(name: string, value: string): void {
+    requiredArguments("Headers.set", arguments.length, 2);
+    const [newname, newvalue] = this._normalizeParams(name, value);
+    this._validateName(newname);
+    this._validateValue(newvalue);
+    this[headerMap].set(newname, newvalue);
+  }
+
+  get [Symbol.toStringTag](): string {
+    return "Headers";
+  }
+}
+
+// @internal
+export class Headers extends DomIterableMixin<
+  string,
+  string,
+  typeof HeadersBase
+>(HeadersBase, headerMap) {}