Fix node v7 incompatibility

Author: Faleij

src/JsonStreamStringify.ts

@@ -112,7 +112,7 @@ function quoteString(string: string) {
 
 function readAsPromised(stream: Readable, size?) {
   const value = stream.read(size);
-  if (value === null && !stream.readableEnded) {
+  if (value === null && !(stream.readableEnded || (stream as any)._readableState?.ended)) {
     return new Promise((resolve, reject) => {
       const endListener = () => resolve(null);
       stream.once('end', endListener);

test-src/JsonStreamStringify.spec.ts

@@ -418,17 +418,19 @@ describe('JsonStreamStringify', function () {
     a.on('data', (data) => {
       out += data.toString();
     }).pause();
+    let ended = false;
     read();
     function read() {
       if (a.readableEnded) return;
       for (let i = 0; i < 10; i++) {
         a._read(); // simulate bad forced read
         a.read(); // legitimate read call
         a._read(); // simulate bad forced read
-        if (!p.writableEnded && i === 8) p.write(c++);
+        if (!(p.writableEnded || ended) && i === 8) p.write(c++);
         a._read(); // simulate bad forced read
       }
-      if (!p.writableEnded && c > 3) {
+      if (!(p.writableEnded || ended) && c > 3) {
+        ended = true;
         p.end();
         // p.read();
         setTimeout(read, 10);