Make streaming functionality optional (#172)

* Add readable-stream as optional dependency

* Attempt to use readable-stream if available, falling back on native stream, and if neither are available, throwing an error when calling stream

Author: mattt

lib/stream.js

@@ -1,4 +1,14 @@
-const { Readable } = require("stream");
+// Attempt to use readable-stream if available, attempt to use the built-in stream module.
+let Readable;
+try {
+  Readable = require("readable-stream").Readable;
+} catch (e) {
+  try {
+    Readable = require("stream").Readable;
+  } catch (e) {
+    Readable = null;
+  }
+}
 
 /**
  * A server-sent event.
@@ -42,6 +52,12 @@ class Stream extends Readable {
    * @param {object} options The fetch options.
    */
   constructor(url, options) {
+    if (!Readable) {
+      throw new Error(
+        "Readable streams are not supported. Please use Node.js 18 or later, or install the readable-stream package."
+      );
+    }
+
     super();
     this.url = url;
     this.options = options;

package-lock.json

@@ -19,6 +19,9 @@
     "lint": "biome lint .",
     "test": "jest"
   },
+  "optionalDependencies": {
+    "readable-stream": ">=4.0.0"
+  },
   "devDependencies": {
     "@biomejs/biome": "^1.4.1",
     "@types/jest": "^29.5.3",