From cb48e8b40703b955391070642e555f82771a910c Mon Sep 17 00:00:00 2001
From: Sergei Zharinov <zharinov@users.noreply.github.com>
Date: Wed, 3 Dec 2025 12:13:13 -0300
Subject: [PATCH] fix: Recursion and exec fuel interference with `debug_fuel`

---
 crates/plotnik-lib/src/ast/parser/core.rs     |  2 +-
 .../src/ast/parser/tests/recovery/coverage.rs | 88 ++++++++++++++++---
 .../ast/parser/tests/recovery/incomplete.rs   | 20 -----
 3 files changed, 77 insertions(+), 33 deletions(-)

diff --git a/crates/plotnik-lib/src/ast/parser/core.rs b/crates/plotnik-lib/src/ast/parser/core.rs
index b3b57a86..141d6d8a 100644
--- a/crates/plotnik-lib/src/ast/parser/core.rs
+++ b/crates/plotnik-lib/src/ast/parser/core.rs
@@ -20,7 +20,7 @@ use crate::ast::syntax_kind::{SyntaxKind, TokenSet};
 const DEFAULT_DEBUG_FUEL: u32 = 256;
 
 const DEFAULT_EXEC_FUEL: u32 = 1_000_000;
-const DEFAULT_RECURSION_FUEL: u32 = 512;
+const DEFAULT_RECURSION_FUEL: u32 = 4096;
 
 /// Parse result containing the green tree and any errors.
 ///
diff --git a/crates/plotnik-lib/src/ast/parser/tests/recovery/coverage.rs b/crates/plotnik-lib/src/ast/parser/tests/recovery/coverage.rs
index 603e57e0..c4ba10ca 100644
--- a/crates/plotnik-lib/src/ast/parser/tests/recovery/coverage.rs
+++ b/crates/plotnik-lib/src/ast/parser/tests/recovery/coverage.rs
@@ -320,17 +320,18 @@ fn capture_at_start_of_alternation() {
 
 #[test]
 fn deeply_nested_trees_hit_recursion_limit() {
-    // Test just over recursion limit (default is 512)
-    let depth = 513;
+    let depth = 128;
     let mut input = String::new();
-    for _ in 0..depth {
+    for _ in 0..depth + 1 {
         input.push_str("(a ");
     }
     for _ in 0..depth {
         input.push(')');
     }
 
-    let result = Query::builder(&input).with_debug_fuel(None).build();
+    let result = Query::builder(&input)
+        .with_recursion_fuel(Some(depth))
+        .build();
 
     assert!(
         matches!(result, Err(crate::Error::RecursionLimitExceeded)),
@@ -341,17 +342,18 @@ fn deeply_nested_trees_hit_recursion_limit() {
 
 #[test]
 fn deeply_nested_sequences_hit_recursion_limit() {
-    // Test just over recursion limit (default is 512)
-    let depth = 513;
+    let depth = 128;
     let mut input = String::new();
-    for _ in 0..depth {
+    for _ in 0..depth + 1 {
         input.push_str("{(a) ");
     }
     for _ in 0..depth {
         input.push('}');
     }
 
-    let result = Query::builder(&input).with_debug_fuel(None).build();
+    let result = Query::builder(&input)
+        .with_recursion_fuel(Some(depth))
+        .build();
 
     assert!(
         matches!(result, Err(crate::Error::RecursionLimitExceeded)),
@@ -362,17 +364,18 @@ fn deeply_nested_sequences_hit_recursion_limit() {
 
 #[test]
 fn deeply_nested_alternations_hit_recursion_limit() {
-    // Test just over recursion limit (default is 512)
-    let depth = 513;
+    let depth = 128;
     let mut input = String::new();
-    for _ in 0..depth {
+    for _ in 0..depth + 1 {
         input.push_str("[(a) ");
     }
     for _ in 0..depth {
         input.push(']');
     }
 
-    let result = Query::builder(&input).with_debug_fuel(None).build();
+    let result = Query::builder(&input)
+        .with_recursion_fuel(Some(depth))
+        .build();
 
     assert!(
         matches!(result, Err(crate::Error::RecursionLimitExceeded)),
@@ -964,3 +967,64 @@ fn paren_close_inside_sequence() {
       | ^^^^ unnamed definition must be last in file; add a name: `Name = {(a)`
     "#);
 }
+
+#[test]
+fn many_trees_exhaust_exec_fuel() {
+    let count = 500;
+    let mut input = String::new();
+    for _ in 0..count {
+        input.push_str("(a) ");
+    }
+
+    let result = Query::builder(&input).with_exec_fuel(Some(100)).build();
+
+    assert!(
+        matches!(result, Err(crate::Error::ExecFuelExhausted)),
+        "expected ExecFuelExhausted error, got {:?}",
+        result
+    );
+}
+
+#[test]
+fn many_branches_exhaust_exec_fuel() {
+    let count = 500;
+    let mut input = String::new();
+    input.push('[');
+    for i in 0..count {
+        if i > 0 {
+            input.push(' ');
+        }
+        input.push_str("(a)");
+    }
+    input.push(']');
+
+    let result = Query::builder(&input).with_exec_fuel(Some(100)).build();
+
+    assert!(
+        matches!(result, Err(crate::Error::ExecFuelExhausted)),
+        "expected ExecFuelExhausted error, got {:?}",
+        result
+    );
+}
+
+#[test]
+fn many_fields_exhaust_exec_fuel() {
+    let count = 500;
+    let mut input = String::new();
+    input.push('(');
+    for i in 0..count {
+        if i > 0 {
+            input.push(' ');
+        }
+        input.push_str("a: (b)");
+    }
+    input.push(')');
+
+    let result = Query::builder(&input).with_exec_fuel(Some(100)).build();
+
+    assert!(
+        matches!(result, Err(crate::Error::ExecFuelExhausted)),
+        "expected ExecFuelExhausted error, got {:?}",
+        result
+    );
+}
diff --git a/crates/plotnik-lib/src/ast/parser/tests/recovery/incomplete.rs b/crates/plotnik-lib/src/ast/parser/tests/recovery/incomplete.rs
index 383790da..7561167c 100644
--- a/crates/plotnik-lib/src/ast/parser/tests/recovery/incomplete.rs
+++ b/crates/plotnik-lib/src/ast/parser/tests/recovery/incomplete.rs
@@ -208,23 +208,3 @@ fn bare_missing_keyword() {
       | ^^^^^^^ ERROR and MISSING must be inside parentheses: (ERROR) or (MISSING ...)
     "#);
 }
-
-#[test]
-fn deep_nesting_within_limit() {
-    let depth = 100;
-    let mut input = String::new();
-    for _ in 0..depth {
-        input.push_str("(a ");
-    }
-    for _ in 0..depth {
-        input.push(')');
-    }
-
-    let result = crate::ast::parser::parse(&input).unwrap();
-    assert!(
-        result.is_valid(),
-        "expected no errors for depth {}, got: {:?}",
-        depth,
-        result.errors()
-    );
-}