Enable string subscripting and verify builtin methods in eldritch-core

docs/_docs/user-guide/eldritchv2.md

@@ -1965,7 +1965,6 @@ It supports:
     - `args` (`List<str>`): List of arguments.
     - `disown` (`Option<bool>`): If `True`, runs in background/detached.
     - `env_vars` (`Option<Dict<str, str>>`): Environment variables to set.
-    - `input` (`Option<String>`): String to pass to process stdin
 
     **Returns**
     - `Dict`: Output containing `stdout`, `stderr`, and `status` (exit code).

implants/lib/eldritchv2/eldritch-core/src/interpreter/eval.rs

@@ -279,6 +279,33 @@ fn evaluate_index(
                 ),
             }
         }
+        Value::String(s) => {
+            let idx_int = match idx_val {
+                Value::Int(i) => i,
+                _ => {
+                    return interp.error(
+                        EldritchErrorKind::TypeError,
+                        "string indices must be integers",
+                        index.span,
+                    );
+                }
+            };
+            let chars: Vec<char> = s.chars().collect();
+            let len = chars.len() as i64;
+            let true_idx = if idx_int < 0 {
+                len + idx_int
+            } else {
+                idx_int
+            };
+            if true_idx < 0 || true_idx as usize >= chars.len() {
+                return interp.error(
+                    EldritchErrorKind::IndexError,
+                    "String index out of range",
+                    span,
+                );
+            }
+            Ok(Value::String(chars[true_idx as usize].to_string()))
+        }
         _ => interp.error(
             EldritchErrorKind::TypeError,
             &format!("'{}' object is not subscriptable", get_type_name(&obj_val)),

implants/lib/eldritchv2/eldritch-core/src/interpreter/introspection.rs

@@ -78,18 +78,7 @@ pub fn get_dir_attributes(value: &Value) -> Vec<String> {
             "union".to_string(),
             "update".to_string(),
         ],
-        Value::String(_) => vec![
-            "endswith".to_string(),
-            "find".to_string(),
-            "format".to_string(),
-            "join".to_string(),
-            "lower".to_string(),
-            "replace".to_string(),
-            "split".to_string(),
-            "startswith".to_string(),
-            "strip".to_string(),
-            "upper".to_string(),
-        ],
+        Value::String(s) => super::methods::get_native_methods(&Value::String(s.clone())),
         Value::Foreign(f) => f.method_names(),
         _ => Vec::new(),
     };

implants/lib/eldritchv2/eldritch-core/tests/coverage_boost_extra.rs

@@ -25,10 +25,7 @@ fn test_eval_index_out_of_bounds() {
     assert::fail("(1,)[-2]", "Tuple index out of range");
 
     // String
-    // Eldritch doesn't seem to support string indexing in eval.rs yet?
-    // Wait, evaluate_index only handles List, Tuple, Dictionary.
-    // Let's verify this failure.
-    assert::fail("'abc'[0]", "'string' object is not subscriptable");
+    assert::fail("'abc'[10]", "String index out of range");
 }
 
 #[test]