feat: make policy length limits configurable per engine (#624)

- Add PolicyLengthConfig struct with max_col, max_file_bytes, and
  max_lines fields, replacing hardcoded constants in the lexer.
- Add Engine::set_policy_length_config and clear_policy_length_config
  to allow callers to override the default limits.
- Add Source::from_contents_with_limits and from_file_with_limits for
  direct Source construction with custom limits; existing from_contents
  and from_file signatures are preserved using defaults.
- Add tests for default rejection, custom limits, and engine plumbing.
- Add bindings for C, C++, Python, WASM/JS, Java, Ruby, C#, Go

bindings/wasm/Cargo.lock

@@ -941,6 +941,7 @@ dependencies = [
  "getrandom 0.3.4",
  "regorus",
  "serde",
+ "serde-wasm-bindgen",
  "serde_json",
  "uuid",
  "wasm-bindgen",
@@ -990,6 +991,17 @@ dependencies = [
  "serde_derive",
 ]
 
+[[package]]
+name = "serde-wasm-bindgen"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8302e169f0eddcc139c70f139d19d6467353af16f9fce27e8c30158036a1e16b"
+dependencies = [
+ "js-sys",
+ "serde",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "serde_core"
 version = "1.0.228"

bindings/wasm/Cargo.toml

@@ -42,6 +42,7 @@ regorus = { path  = "../..", default-features = false, features = ["arc", "rvm"]
 serde = { version = "1.0.219", features = ["derive"] }
 serde_json = "1.0.140"
 wasm-bindgen = "0.2.100"
+serde-wasm-bindgen = "0.6"
 # Specify uuid as a mandatory dependency so as to enable `js` feature which is now required
 # when targeting wasm32-unknown-unknown.
 uuid = { version = "1.15.1", default-features = false, features = ["v4", "fast-rng", "js"]}

bindings/wasm/src/lib.rs

@@ -3,6 +3,7 @@
 
 #![allow(non_snake_case)]
 
+use core::num::{NonZeroU32, NonZeroUsize};
 use regorus::languages::rego::compiler::Compiler;
 use regorus::rvm::program::{
     generate_assembly_listing, generate_tabular_assembly_listing, AssemblyListingConfig,
@@ -26,6 +27,14 @@ struct ModuleSpec {
     content: String,
 }
 
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct PolicyLengthSpec {
+    max_col: u32,
+    max_file_bytes: usize,
+    max_lines: usize,
+}
+
 #[wasm_bindgen]
 pub struct Program {
     program: Arc<RvmProgram>,
@@ -183,6 +192,29 @@ impl Engine {
         self.engine.set_gather_prints(b)
     }
 
+    /// Set the policy length limits used when loading policies.
+    ///
+    /// Accepts a JS object: `{ maxCol, maxFileBytes, maxLines }`.
+    pub fn setPolicyLengthConfig(&mut self, config: JsValue) -> Result<(), JsValue> {
+        let spec: PolicyLengthSpec =
+            serde_wasm_bindgen::from_value(config).map_err(error_to_jsvalue)?;
+        self.engine
+            .set_policy_length_config(regorus::PolicyLengthConfig {
+                max_col: NonZeroU32::new(spec.max_col)
+                    .ok_or_else(|| JsValue::from_str("maxCol must be non-zero"))?,
+                max_file_bytes: NonZeroUsize::new(spec.max_file_bytes)
+                    .ok_or_else(|| JsValue::from_str("maxFileBytes must be non-zero"))?,
+                max_lines: NonZeroUsize::new(spec.max_lines)
+                    .ok_or_else(|| JsValue::from_str("maxLines must be non-zero"))?,
+            });
+        Ok(())
+    }
+
+    /// Clear the policy length configuration, reverting to defaults.
+    pub fn clearPolicyLengthConfig(&mut self) {
+        self.engine.clear_policy_length_config();
+    }
+
     /// Take the gathered output of print statements.
     ///
     /// See https://docs.rs/regorus/latest/regorus/struct.Engine.html#method.take_prints

bindings/wasm/test.js

@@ -9,6 +9,9 @@ var engine = new regorus.Engine();
 // Enable code coverage
 engine.setEnableCoverage(true);
 
+// Raise the default col limit to 2000
+engine.setPolicyLengthConfig({ maxCol: 2000, maxFileBytes: 1048576, maxLines: 20000 });
+
 // Add Rego policy.
 var pkg = engine.addPolicy(
     // Associate this file name with policy