1 files changed, 72 insertions, 0 deletions
diff --git a/js/xpconnect/tests/unit/test_envChain_subscript.js b/js/xpconnect/tests/unit/test_envChain_subscript.js
new file mode 100644
index 0000000000..e7774d0d0d
--- /dev/null
+++ b/js/xpconnect/tests/unit/test_envChain_subscript.js
@@ -0,0 +1,72 @@
+/* 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";
+
+// Verify the environment chain for subscripts described in
+// js/src/vm/EnvironmentObject.h.
+
+add_task(async function() {
+  const target = {};
+  Services.scriptloader.loadSubScript(`data:,
+var qualified = 10;
+unqualified = 20;
+let lexical = 30;
+this.prop = 40;
+
+const funcs = Cu.getJSTestingFunctions();
+const envs = [];
+let env = funcs.getInnerMostEnvironmentObject();
+while (env) {
+  envs.push({
+    type: funcs.getEnvironmentObjectType(env) || "*global*",
+    qualified: !!Object.getOwnPropertyDescriptor(env, "qualified"),
+    unqualified: !!Object.getOwnPropertyDescriptor(env, "unqualified"),
+    lexical: !!Object.getOwnPropertyDescriptor(env, "lexical"),
+    prop: !!Object.getOwnPropertyDescriptor(env, "prop"),
+  });
+
+  env = funcs.getEnclosingEnvironmentObject(env);
+}
+
+this.ENVS = envs;
+`, target);
+
+  const envs = target.ENVS;
+
+  Assert.equal(envs.length, 4);
+
+  let i = 0, env;
+
+  env = envs[i]; i++;
+  Assert.equal(env.type, "NonSyntacticLexicalEnvironmentObject");
+  Assert.equal(env.qualified, false);
+  Assert.equal(env.unqualified, false);
+  Assert.equal(env.lexical, true, "lexical must live in the NSLEO");
+  Assert.equal(env.prop, false);
+
+  env = envs[i]; i++;
+  Assert.equal(env.type, "WithEnvironmentObject");
+  Assert.equal(env.qualified, true, "qualified var must live in the with env");
+  Assert.equal(env.unqualified, false);
+  Assert.equal(env.lexical, false);
+  Assert.equal(env.prop, true, "this property must live in the with env");
+
+  env = envs[i]; i++;
+  Assert.equal(env.type, "GlobalLexicalEnvironmentObject");
+  Assert.equal(env.qualified, false);
+  Assert.equal(env.unqualified, false);
+  Assert.equal(env.lexical, false);
+  Assert.equal(env.prop, false);
+
+  env = envs[i]; i++;
+  Assert.equal(env.type, "*global*");
+  Assert.equal(env.qualified, false);
+  Assert.equal(env.unqualified, true, "unqualified var must live in the global");
+  Assert.equal(env.lexical, false);
+  Assert.equal(env.prop, false);
+
+  Assert.equal(target.qualified, 10, "qualified var must be reflected to the target object");
+  Assert.equal(target.prop, 40, "this property must be reflected to the target object");
+});