Adds a new API setIsBuffered to allow clients to set connection statu…

…s. This can be used by clients that perform additional tests to determine if a connection is actually buffered or not after initial load.

RELNOTES: Adds a new API setIsBuffered to allow clients to set connection status

PiperOrigin-RevId: 518289912
Change-Id: Iab16a025ef72c545f572fe4aa4e5689011a9447d

closure/goog/net/browserchannel.js

@@ -1027,6 +1027,24 @@ goog.net.BrowserChannel.prototype.isBuffered = function() {
 };
 
 
+/**
+ * Sets whether the channel is buffered or not. This state is usually updated in
+ * goog.net.BrowserChannel.testConnectionFinished, but can be set manually here.
+ * This updated status will be reflected in subsequent connections and requests
+ * to the channel.
+ * NOTE: This should ONLY be used by clients that are certain of their
+ * connection status, i.e. that have performed additional test channels. Setting
+ * the wrong buffered status on a client can result in undeliverable responses
+ * from the server.
+ * @param {boolean} isBuffered Whether the channel is buffered.
+ */
+goog.net.BrowserChannel.prototype.setIsBuffered = function(isBuffered) {
+  'use strict';
+  this.useChunked_ = !isBuffered;
+  this.secondTestResults_ = isBuffered;
+};
+
+
 /**
  * Returns whether chunked mode is allowed. In certain debugging situations,
  * it's useful for the application to have a way to disable chunked mode for a
@@ -1652,7 +1670,14 @@ goog.net.BrowserChannel.prototype.testConnectionFinished = function(
   'use strict';
   this.channelDebug_.debug('Test Connection Finished');
 
-  this.useChunked_ = this.allowChunkedMode_ && useChunked;
+  // Use the results of the second phase of the test channel if user decided to
+  // override the test results while the test was ongoing.
+  if (this.secondTestResults_ == null) {
+    this.useChunked_ = this.allowChunkedMode_ && useChunked;
+  } else {
+    this.useChunked_ = !this.secondTestResults_;
+  }
+
   this.lastStatusCode_ = testChannel.getLastStatusCode();
   // When using asynchronous test, the channel is already open by connect().
   if (!this.asyncTest_) {

closure/goog/net/browserchannel_test.js

@@ -406,6 +406,9 @@ testSuite({
 
     numStatEvents = 0;
     lastStatEvent = null;
+
+    /** @suppress {visibility} suppression added to enable type checking */
+    browserChannel.asyncTest_ = false;
   },
 
   tearDown() {
@@ -1317,4 +1320,25 @@ testSuite({
         '0',
         browserChannel.backChannelRequest_.requestUri_.queryData_.get('CI'));
   },
+
+  /** @suppress {visibility} suppression added to enable type checking */
+  testSetIsBuffered() {
+    connect();
+    browserChannel.setIsBuffered(true);
+    completeBackChannel();
+    browserChannel.setIsBuffered(false);
+
+    // Back channel will still be buffered, because #setIsBuffered was called
+    // after the back channel was already open.
+    assertEquals(
+        '1',
+        browserChannel.backChannelRequest_.requestUri_.queryData_.get('CI'));
+
+    // Subsequent back channels that are opened will be streaming.
+    completeBackChannel();
+    assertFalse(browserChannel.isBuffered());
+    assertEquals(
+        '0',
+        browserChannel.backChannelRequest_.requestUri_.queryData_.get('CI'));
+  },
 });