1 files changed, 59 insertions, 19 deletions
diff --git a/src/js/builtins/ConsoleObject.ts b/src/js/builtins/ConsoleObject.ts
index 45746459a..2d657a78b 100644
--- a/src/js/builtins/ConsoleObject.ts
+++ b/src/js/builtins/ConsoleObject.ts
@@ -1,18 +1,55 @@
 $overriddenName = "[Symbol.asyncIterator]";
 export function asyncIterator(this: Console) {
-  const Iterator = async function* ConsoleAsyncIterator() {
-    const stream = Bun.stdin.stream();
-    var reader = stream.getReader();
+  var stream = Bun.stdin.stream();
 
-    // TODO: use builtin
-    var decoder = new (globalThis as any).TextDecoder("utf-8", { fatal: false }) as TextDecoder;
-    var deferredError;
-    var indexOf = Bun.indexOfLine;
+  var decoder = new TextDecoder("utf-8", { fatal: false });
+  var indexOf = Bun.indexOfLine;
+  var actualChunk: Uint8Array;
+  var i: number = -1;
+  var idx: number;
+  var last: number;
+  var done: boolean;
+  var value: Uint8Array[];
+  var value_len: number;
+  var pendingChunk: Uint8Array | undefined;
 
+  async function* ConsoleAsyncIterator() {
+    var reader = stream.getReader();
+    var deferredError;
     try {
+      if (i !== -1) {
+        last = i + 1;
+        i = indexOf(actualChunk, last);
+
+        while (i !== -1) {
+          yield decoder.decode(actualChunk.subarray(last, i));
+          last = i + 1;
+          i = indexOf(actualChunk, last);
+        }
+
+        for (idx++; idx < value_len; idx++) {
+          actualChunk = value[idx];
+          if (pendingChunk) {
+            actualChunk = Buffer.concat([pendingChunk, actualChunk]);
+            pendingChunk = undefined;
+          }
+
+          last = 0;
+          // TODO: "\r", 0x4048, 0x4049, 0x404A, 0x404B, 0x404C, 0x404D, 0x404E, 0x404F
+          i = indexOf(actualChunk, last);
+          while (i !== -1) {
+            yield decoder.decode(actualChunk.subarray(last, i));
+            last = i + 1;
+            i = indexOf(actualChunk, last);
+          }
+          i = -1;
+
+          pendingChunk = actualChunk.subarray(last);
+        }
+        actualChunk = undefined!;
+      }
+
       while (true) {
-        var done, value;
-        var pendingChunk;
         const firstResult = reader.readMany();
         if ($isPromise(firstResult)) {
           ({ done, value } = await firstResult);
@@ -27,26 +64,29 @@ export function asyncIterator(this: Console) {
           return;
         }
 
-        var actualChunk;
         // we assume it was given line-by-line
-        for (const chunk of value) {
-          actualChunk = chunk;
+        for (idx = 0, value_len = value.length; idx < value_len; idx++) {
+          actualChunk = value[idx];
           if (pendingChunk) {
-            actualChunk = Buffer.concat([pendingChunk, chunk]);
-            pendingChunk = null;
+            actualChunk = Buffer.concat([pendingChunk, actualChunk]);
+            pendingChunk = undefined;
           }
 
-          var last = 0;
+          last = 0;
           // TODO: "\r", 0x4048, 0x4049, 0x404A, 0x404B, 0x404C, 0x404D, 0x404E, 0x404F
-          var i = indexOf(actualChunk, last);
+          i = indexOf(actualChunk, last);
           while (i !== -1) {
+            // This yield may end the function, in that case we need to be able to recover state
+            // if the iterator was fired up again.
             yield decoder.decode(actualChunk.subarray(last, i));
             last = i + 1;
             i = indexOf(actualChunk, last);
           }
+          i = -1;
 
           pendingChunk = actualChunk.subarray(last);
         }
+        actualChunk = undefined!;
       }
     } catch (e) {
       deferredError = e;
@@ -57,11 +97,11 @@ export function asyncIterator(this: Console) {
         throw deferredError;
       }
     }
-  };
+  }
 
   const symbol = globalThis.Symbol.asyncIterator;
-  this[symbol] = Iterator;
-  return Iterator();
+  this[symbol] = ConsoleAsyncIterator;
+  return ConsoleAsyncIterator();
 }
 
 export function write(this: Console, input) {