1 files changed, 60 insertions, 0 deletions
diff --git a/devtools/client/fronts/string.js b/devtools/client/fronts/string.js
new file mode 100644
index 0000000000..f9b42e260c
--- /dev/null
+++ b/devtools/client/fronts/string.js
@@ -0,0 +1,60 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+const { DevToolsServer } = require("devtools/server/devtools-server");
+const {
+  longStringSpec,
+  SimpleStringFront,
+} = require("devtools/shared/specs/string");
+const {
+  FrontClassWithSpec,
+  registerFront,
+} = require("devtools/shared/protocol");
+
+class LongStringFront extends FrontClassWithSpec(longStringSpec) {
+  destroy() {
+    this.initial = null;
+    this.length = null;
+    this.strPromise = null;
+    super.destroy();
+  }
+
+  form(data) {
+    this.actorID = data.actor;
+    this.initial = data.initial;
+    this.length = data.length;
+
+    this._grip = data;
+  }
+
+  // We expose the grip so consumers (e.g. ObjectInspector) that handle webconsole
+  // evaluations (which can return primitive, object fronts or longString front),
+  // can directly call this without further check.
+  getGrip() {
+    return this._grip;
+  }
+
+  string() {
+    if (!this.strPromise) {
+      const promiseRest = thusFar => {
+        if (thusFar.length === this.length) {
+          return Promise.resolve(thusFar);
+        }
+        return this.substring(
+          thusFar.length,
+          thusFar.length + DevToolsServer.LONG_STRING_READ_LENGTH
+        ).then(next => promiseRest(thusFar + next));
+      };
+
+      this.strPromise = promiseRest(this.initial);
+    }
+    return this.strPromise;
+  }
+}
+
+exports.LongStringFront = LongStringFront;
+registerFront(LongStringFront);
+exports.SimpleStringFront = SimpleStringFront;
+registerFront(SimpleStringFront);