1 files changed, 60 insertions, 0 deletions
diff --git a/devtools/client/inspector/rules/test/browser_rules_computed-lists_01.js b/devtools/client/inspector/rules/test/browser_rules_computed-lists_01.js
new file mode 100644
index 0000000000..af7c03220a
--- /dev/null
+++ b/devtools/client/inspector/rules/test/browser_rules_computed-lists_01.js
@@ -0,0 +1,60 @@
+/* Any copyright is dedicated to the Public Domain.
+ http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Tests that the rule view shows expanders for properties with computed lists.
+
+var TEST_URI = `
+  <style type="text/css">
+    #testid {
+      margin: 4px;
+      top: 0px;
+    }
+  </style>
+  <h1 id="testid">Styled Node</h1>
+`;
+
+add_task(async function () {
+  await addTab("data:text/html;charset=utf-8," + encodeURIComponent(TEST_URI));
+  const { inspector, view } = await openRuleView();
+  await selectNode("#testid", inspector);
+  await testExpandersShown(inspector, view);
+});
+
+function testExpandersShown(inspector, view) {
+  const rule = getRuleViewRuleEditor(view, 1).rule;
+
+  info("Check that the correct rules are visible");
+  is(rule.selectorText, "#testid", "Second rule is #testid.");
+  is(rule.textProps[0].name, "margin", "First property is margin.");
+  is(rule.textProps[1].name, "top", "Second property is top.");
+
+  info("Check that the expanders are shown correctly");
+  is(
+    rule.textProps[0].editor.expander.style.display,
+    "inline-block",
+    "margin expander is displayed."
+  );
+  is(
+    rule.textProps[1].editor.expander.style.display,
+    "none",
+    "top expander is hidden."
+  );
+  ok(
+    !rule.textProps[0].editor.expander.hasAttribute("open"),
+    "margin computed list is closed."
+  );
+  ok(
+    !rule.textProps[1].editor.expander.hasAttribute("open"),
+    "top computed list is closed."
+  );
+  ok(
+    !rule.textProps[0].editor.computed.hasChildNodes(),
+    "margin computed list is empty before opening."
+  );
+  ok(
+    !rule.textProps[1].editor.computed.hasChildNodes(),
+    "top computed list is empty."
+  );
+}