Bug 1600058 - [remote] Implement IO.close. r=remote-protocol-reviewers,ato,maja_zf

Differential Revision: https://phabricator.services.mozilla.com/D55969

--HG--
extra : moz-landing-system : lando

remote/domains/parent/IO.jsm

@@ -29,6 +29,23 @@ const streamRegistry = new StreamRegistry();
 class IO extends Domain {
   // commands
 
+  /**
+   * Close the stream, discard any temporary backing storage.
+   *
+   * @param {Object} options
+   * @param {string} options.handle
+   *     Handle of the stream to close.
+   */
+  async close(options) {
+    const { handle } = options;
+
+    if (typeof handle != "string") {
+      throw new TypeError(`handle: string value expected`);
+    }
+
+    await streamRegistry.remove(handle);
+  }
+
   /**
    * Read a chunk of the stream.
    *

remote/test/browser/io/browser.ini

@@ -7,4 +7,5 @@ support-files =
   !/remote/test/browser/chrome-remote-interface.js
   !/remote/test/browser/head.js
 
+[browser_close.js]
 [browser_read.js]

remote/test/browser/io/browser_close.js

@@ -0,0 +1,40 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function fileRemovedAfterClose({ IO }) {
+  const contents = "Lorem ipsum";
+  const { handle, path } = await registerFileStream(contents);
+
+  await IO.close({ handle });
+  ok(!(await OS.File.exists(path)), "Discarded the temporary backing storage");
+});
+
+add_task(async function unknownHandle({ IO }) {
+  const handle = "1000000";
+
+  try {
+    await IO.close({ handle });
+    ok(false, "Close shouldn't pass");
+  } catch (e) {
+    ok(
+      e.message.startsWith(`Invalid stream handle`),
+      "Error contains expected message"
+    );
+  }
+});
+
+add_task(async function invalidHandleTypes({ IO }) {
+  for (const handle of [null, true, 1, [], {}]) {
+    try {
+      await IO.close({ handle });
+      ok(false, "Close shouldn't pass");
+    } catch (e) {
+      ok(
+        e.message.startsWith(`handle: string value expected`),
+        "Error contains expected message"
+      );
+    }
+  }
+});

remote/test/browser/io/browser_read.js

@@ -67,6 +67,23 @@ add_task(async function readBySize({ IO }) {
   }
 });
 
+add_task(async function readAfterClose({ IO }) {
+  const contents = "Lorem ipsum";
+  const { handle } = await registerFileStream(contents);
+
+  await IO.close({ handle });
+
+  try {
+    await IO.read({ handle });
+    ok(false, "Read shouldn't pass");
+  } catch (e) {
+    ok(
+      e.message.startsWith(`Invalid stream handle`),
+      "Error contains expected message"
+    );
+  }
+});
+
 add_task(async function unknownHandle({ IO }) {
   const handle = "1000000";