lexical_envs/add_env_post: transition to lkt compile

testsuite/tests/lexical_envs/add_env_post/test.lkt

@@ -0,0 +1,18 @@
+# Check that add_env is forbidden in post-node PLE
+
+import lexer_example
+
+@with_lexer(foo_lexer)
+grammar foo_grammar {
+    @main_rule main_rule <- Example("example")
+}
+
+class FooNode implements Node[FooNode] {
+}
+
+class Example: FooNode implements TokenNode {
+    env_spec {
+        handle_children()
+        add_env()
+    }
+}

testsuite/tests/lexical_envs/add_env_post/test.out

@@ -1,2 +1,7 @@
-test.py:XXX: error: add_env() must occur before processing children
-Done
+== test.lkt ==
+test.lkt:16:9: error: add_env() must occur before processing children
+16 |         add_env()
+   |         ^^^^^^^^^
+
+
+lkt_compile: Done

testsuite/tests/lexical_envs/add_env_post/test.py

@@ -1,25 +0,0 @@
-"""
-Check that add_env is forbidden in post-node PLE.
-"""
-
-from langkit.diagnostics import DiagnosticError
-from langkit.dsl import ASTNode
-from langkit.envs import EnvSpec, add_env, handle_children
-
-
-class FooNode(ASTNode):
-    pass
-
-
-try:
-    class Example(FooNode):
-        token_node = True
-
-        env_spec = EnvSpec(
-            handle_children(),
-            add_env(),
-        )
-except DiagnosticError:
-    pass
-
-print('Done')

testsuite/tests/lexical_envs/add_env_post/test.yaml

@@ -1 +1 @@
-driver: python
+driver: lkt_compile