1 files changed, 35 insertions, 0 deletions
diff --git a/devtools/server/tests/xpcshell/test_getTextAtLineColumn.js b/devtools/server/tests/xpcshell/test_getTextAtLineColumn.js
new file mode 100644
index 0000000000..7c6a2e67ce
--- /dev/null
+++ b/devtools/server/tests/xpcshell/test_getTextAtLineColumn.js
@@ -0,0 +1,35 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const {
+  getTextAtLineColumn,
+} = require("devtools/server/actors/utils/style-utils");
+
+const TEST_DATA = [
+  {
+    desc: "simplest",
+    input: "#id{color:red;background:yellow;}",
+    line: 1,
+    column: 5,
+    expected: { offset: 4, text: "color:red;background:yellow;}" },
+  },
+  {
+    desc: "multiple lines",
+    input: "one\n two\n  three",
+    line: 3,
+    column: 3,
+    expected: { offset: 11, text: "three" },
+  },
+];
+
+function run_test() {
+  for (const test of TEST_DATA) {
+    info("Starting test: " + test.desc);
+    info("Input string " + test.input);
+
+    const output = getTextAtLineColumn(test.input, test.line, test.column);
+    deepEqual(output, test.expected);
+  }
+}