Parse tool name for command line lint options

compiler/rustc_lint/src/tests.rs

@@ -0,0 +1,24 @@
+use crate::context::parse_lint_and_tool_name;
+use rustc_span::{with_default_session_globals, Symbol};
+
+#[test]
+fn parse_lint_no_tool() {
+    with_default_session_globals(|| assert_eq!(parse_lint_and_tool_name("foo"), (None, "foo")));
+}
+
+#[test]
+fn parse_lint_with_tool() {
+    with_default_session_globals(|| {
+        assert_eq!(parse_lint_and_tool_name("clippy::foo"), (Some(Symbol::intern("clippy")), "foo"))
+    });
+}
+
+#[test]
+fn parse_lint_multiple_path() {
+    with_default_session_globals(|| {
+        assert_eq!(
+            parse_lint_and_tool_name("clippy::foo::bar"),
+            (Some(Symbol::intern("clippy")), "foo::bar")
+        )
+    });
+}