Initial commit

1 files changed, 207 insertions, 0 deletions

diff --git a/node_modules/readable-stream/lib/internal/streams/async_iterator.js b/node_modules/readable-stream/lib/internal/streams/async_iterator.js
new file mode 100644
index 0000000..9fb615a
--- /dev/null
+++ b/node_modules/readable-stream/lib/internal/streams/async_iterator.js
@@ -0,0 +1,207 @@
+'use strict';
+
+var _Object$setPrototypeO;
+
+function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
+
+var finished = require('./end-of-stream');
+
+var kLastResolve = Symbol('lastResolve');
+var kLastReject = Symbol('lastReject');
+var kError = Symbol('error');
+var kEnded = Symbol('ended');
+var kLastPromise = Symbol('lastPromise');
+var kHandlePromise = Symbol('handlePromise');
+var kStream = Symbol('stream');
+
+function createIterResult(value, done) {
+  return {
+    value: value,
+    done: done
+  };
+}
+
+function readAndResolve(iter) {
+  var resolve = iter[kLastResolve];
+
+  if (resolve !== null) {
+    var data = iter[kStream].read(); // we defer if data is null
+    // we can be expecting either 'end' or
+    // 'error'
+
+    if (data !== null) {
+      iter[kLastPromise] = null;
+      iter[kLastResolve] = null;
+      iter[kLastReject] = null;
+      resolve(createIterResult(data, false));
+    }
+  }
+}
+
+function onReadable(iter) {
+  // we wait for the next tick, because it might
+  // emit an error with process.nextTick
+  process.nextTick(readAndResolve, iter);
+}
+
+function wrapForNext(lastPromise, iter) {
+  return function (resolve, reject) {
+    lastPromise.then(function () {
+      if (iter[kEnded]) {
+        resolve(createIterResult(undefined, true));
+        return;
+      }
+
+      iter[kHandlePromise](resolve, reject);
+    }, reject);
+  };
+}
+
+var AsyncIteratorPrototype = Object.getPrototypeOf(function () {});
+var ReadableStreamAsyncIteratorPrototype = Object.setPrototypeOf((_Object$setPrototypeO = {
+  get stream() {
+    return this[kStream];
+  },
+
+  next: function next() {
+    var _this = this;
+
+    // if we have detected an error in the meanwhile
+    // reject straight away
+    var error = this[kError];
+
+    if (error !== null) {
+      return Promise.reject(error);
+    }
+
+    if (this[kEnded]) {
+      return Promise.resolve(createIterResult(undefined, true));
+    }
+
+    if (this[kStream].destroyed) {
+      // We need to defer via nextTick because if .destroy(err) is
+      // called, the error will be emitted via nextTick, and
+      // we cannot guarantee that there is no error lingering around
+      // waiting to be emitted.
+      return new Promise(function (resolve, reject) {
+        process.nextTick(function () {
+          if (_this[kError]) {
+            reject(_this[kError]);
+          } else {
+            resolve(createIterResult(undefined, true));
+          }
+        });
+      });
+    } // if we have multiple next() calls
+    // we will wait for the previous Promise to finish
+    // this logic is optimized to support for await loops,
+    // where next() is only called once at a time
+
+
+    var lastPromise = this[kLastPromise];
+    var promise;
+
+    if (lastPromise) {
+      promise = new Promise(wrapForNext(lastPromise, this));
+    } else {
+      // fast path needed to support multiple this.push()
+      // without triggering the next() queue
+      var data = this[kStream].read();
+
+      if (data !== null) {
+        return Promise.resolve(createIterResult(data, false));
+      }
+
+      promise = new Promise(this[kHandlePromise]);
+    }
+
+    this[kLastPromise] = promise;
+    return promise;
+  }
+}, _defineProperty(_Object$setPrototypeO, Symbol.asyncIterator, function () {
+  return this;
+}), _defineProperty(_Object$setPrototypeO, "return", function _return() {
+  var _this2 = this;
+
+  // destroy(err, cb) is a private API
+  // we can guarantee we have that here, because we control the
+  // Readable class this is attached to
+  return new Promise(function (resolve, reject) {
+    _this2[kStream].destroy(null, function (err) {
+      if (err) {
+        reject(err);
+        return;
+      }
+
+      resolve(createIterResult(undefined, true));
+    });
+  });
+}), _Object$setPrototypeO), AsyncIteratorPrototype);
+
+var createReadableStreamAsyncIterator = function createReadableStreamAsyncIterator(stream) {
+  var _Object$create;
+
+  var iterator = Object.create(ReadableStreamAsyncIteratorPrototype, (_Object$create = {}, _defineProperty(_Object$create, kStream, {
+    value: stream,
+    writable: true
+  }), _defineProperty(_Object$create, kLastResolve, {
+    value: null,
+    writable: true
+  }), _defineProperty(_Object$create, kLastReject, {
+    value: null,
+    writable: true
+  }), _defineProperty(_Object$create, kError, {
+    value: null,
+    writable: true
+  }), _defineProperty(_Object$create, kEnded, {
+    value: stream._readableState.endEmitted,
+    writable: true
+  }), _defineProperty(_Object$create, kHandlePromise, {
+    value: function value(resolve, reject) {
+      var data = iterator[kStream].read();
+
+      if (data) {
+        iterator[kLastPromise] = null;
+        iterator[kLastResolve] = null;
+        iterator[kLastReject] = null;
+        resolve(createIterResult(data, false));
+      } else {
+        iterator[kLastResolve] = resolve;
+        iterator[kLastReject] = reject;
+      }
+    },
+    writable: true
+  }), _Object$create));
+  iterator[kLastPromise] = null;
+  finished(stream, function (err) {
+    if (err && err.code !== 'ERR_STREAM_PREMATURE_CLOSE') {
+      var reject = iterator[kLastReject]; // reject if we are waiting for data in the Promise
+      // returned by next() and store the error
+
+      if (reject !== null) {
+        iterator[kLastPromise] = null;
+        iterator[kLastResolve] = null;
+        iterator[kLastReject] = null;
+        reject(err);
+      }
+
+      iterator[kError] = err;
+      return;
+    }
+
+    var resolve = iterator[kLastResolve];
+
+    if (resolve !== null) {
+      iterator[kLastPromise] = null;
+      iterator[kLastResolve] = null;
+      iterator[kLastReject] = null;
+      resolve(createIterResult(undefined, true));
+    }
+
+    iterator[kEnded] = true;
+  });
+  stream.on('readable', onReadable.bind(null, iterator));
+  return iterator;
+};
+
+module.exports = createReadableStreamAsyncIterator;
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