fix array_index

Author: xuhuanzy

crates/emmylua_code_analysis/src/compilation/test/array_test.rs

@@ -0,0 +1,33 @@
+#[cfg(test)]
+mod test {
+    use std::{ops::Deref, sync::Arc};
+
+    use crate::{DiagnosticCode, VirtualWorkspace};
+
+    #[test]
+    fn test_array_index() {
+        let mut ws = VirtualWorkspace::new();
+        let mut emmyrc = ws.analysis.get_emmyrc().deref().clone();
+        emmyrc.strict.array_index = false;
+        ws.analysis.update_config(Arc::new(emmyrc));
+        ws.def(
+            r#"
+            ---@class Test.Add
+            ---@field a string
+            
+            ---@type int
+            index = 1
+            ---@type Test.Add[]
+            items = {}
+        "#,
+        );
+
+        assert!(ws.check_code_for(
+            DiagnosticCode::NeedCheckNil,
+            r#"
+                local a = items[index]
+                local b = a.a
+        "#,
+        ));
+    }
+}

crates/emmylua_code_analysis/src/compilation/test/mod.rs

@@ -1,5 +1,6 @@
 mod and_or_test;
 mod annotation_test;
+mod array_test;
 mod closure_generic;
 mod closure_param_infer_test;
 mod closure_return_test;

crates/emmylua_code_analysis/src/semantic/infer/infer_index.rs

@@ -243,7 +243,13 @@ fn infer_array_member(
 
                 let result_type = match &base_type {
                     LuaType::Any | LuaType::Unknown => base_type.clone(),
-                    _ => TypeOps::Union.apply(db, base_type, &LuaType::Nil),
+                    _ => {
+                        if db.get_emmyrc().strict.array_index {
+                            TypeOps::Union.apply(db, base_type, &LuaType::Nil)
+                        } else {
+                            base_type.clone()
+                        }
+                    }
                 };
 
                 Ok(result_type)