1 files changed, 73 insertions, 0 deletions
diff --git a/devtools/client/debugger/test/mochitest/browser_dbg-expressions-watch.js b/devtools/client/debugger/test/mochitest/browser_dbg-expressions-watch.js
new file mode 100644
index 0000000000..5dbf65cde9
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+++ b/devtools/client/debugger/test/mochitest/browser_dbg-expressions-watch.js
@@ -0,0 +1,73 @@
+/* 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/>. */
+
+/**
+ * Test the watch expressions "refresh" button:
+ * - hidden when no expression is available
+ * - visible with one or more expressions
+ * - updates expressions values after clicking on it
+ * - disappears when all expressions are removed
+ */
+
+add_task(async function() {
+  const dbg = await initDebugger("doc-script-switching.html");
+
+  invokeInTab("firstCall");
+  await waitForPaused(dbg);
+
+  ok(
+    !getRefreshExpressionsElement(dbg),
+    "No refresh button is displayed when there are no watch expressions"
+  );
+
+  await addExpression(dbg, "someVariable");
+
+  ok(
+    getRefreshExpressionsElement(dbg),
+    "Refresh button is displayed after adding a watch expression"
+  );
+
+  is(getLabel(dbg, 1), "someVariable", "Watch expression was added");
+  is(getValue(dbg, 1), "(unavailable)", "Watch expression has no value");
+
+  info("Switch to the console and update the value of the watched variable");
+  const { hud } = await dbg.toolbox.selectTool("webconsole");
+  await evaluateExpressionInConsole(hud, "var someVariable = 1");
+
+  info("Switch back to the debugger");
+  await dbg.toolbox.selectTool("jsdebugger");
+
+  is(getLabel(dbg, 1), "someVariable", "Watch expression is still available");
+  is(getValue(dbg, 1), "(unavailable)", "Watch expression still has no value");
+
+  info(
+    "Click on the watch expression refresh button and wait for the " +
+      "expression to update."
+  );
+  const refreshed = waitForDispatch(dbg, "EVALUATE_EXPRESSIONS");
+  await clickElement(dbg, "expressionRefresh");
+  await refreshed;
+
+  is(getLabel(dbg, 1), "someVariable", "Watch expression is still available");
+  is(getValue(dbg, 1), "1", "Watch expression value has been updated");
+
+  await deleteExpression(dbg, "someVariable");
+
+  ok(
+    !getRefreshExpressionsElement(dbg),
+    "The refresh button is no longer displayed after removing watch expressions"
+  );
+});
+
+function getLabel(dbg, index) {
+  return findElement(dbg, "expressionNode", index).innerText;
+}
+
+function getValue(dbg, index) {
+  return findElement(dbg, "expressionValue", index).innerText;
+}
+
+function getRefreshExpressionsElement(dbg) {
+  return findElement(dbg, "expressionRefresh", 1);
+}