yanglint TEST for --ext-data by schema mount
diff --git a/tools/lint/tests/modules/modsm-augment.yang b/tools/lint/tests/modules/modsm-augment.yang
new file mode 100644
index 0000000..5d16fbd
--- /dev/null
+++ b/tools/lint/tests/modules/modsm-augment.yang
@@ -0,0 +1,15 @@
+module modsm-augment {
+  yang-version 1.1;
+  namespace "urn:yanglint:modsm-augment";
+  prefix "msa";
+
+  import modsm {
+    prefix msm;
+  }
+
+  augment "/msm:root" {
+    leaf alf {
+      type string;
+    }
+  }
+}
diff --git a/tools/lint/tests/modules/modsm.yang b/tools/lint/tests/modules/modsm.yang
new file mode 100644
index 0000000..dfe8830
--- /dev/null
+++ b/tools/lint/tests/modules/modsm.yang
@@ -0,0 +1,13 @@
+module modsm {
+  yang-version 1.1;
+  namespace "urn:yanglint:modsm";
+  prefix "msm";
+
+  import ietf-yang-schema-mount {
+    prefix sm;
+  }
+
+  container root {
+    sm:mount-point "root";
+  }
+}