From 62d33c4d7e7d2fac99274748b9e59fa6c9f75745 Mon Sep 17 00:00:00 2001
From: Sujay Jayakar <sujayakar314+github@gmail.com>
Date: Tue, 30 Nov 2021 12:55:41 -0800
Subject: [PATCH] Add Function::GetScript{Line,Column}Number bindings (#843)

---
 src/binding.cc    | 10 +++++++-
 src/function.rs   | 14 +++++++++++
 tests/test_api.rs | 59 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 82 insertions(+), 1 deletion(-)

diff --git a/src/binding.cc b/src/binding.cc
index c05b7264..40f215e0 100644
--- a/src/binding.cc
+++ b/src/binding.cc
@@ -1565,6 +1565,14 @@ void v8__Function__SetName(const v8::Function& self, const v8::String& name) {
   return ptr_to_local(&self)->SetName(ptr_to_local(&name));
 }
 
+int v8__Function__GetScriptColumnNumber(const v8::Function& self) {
+  return ptr_to_local(&self)->GetScriptColumnNumber();
+}
+
+int v8__Function__GetScriptLineNumber(const v8::Function& self) {
+  return ptr_to_local(&self)->GetScriptLineNumber();
+}
+
 const v8::Signature* v8__Signature__New(v8::Isolate* isolate,
                                         const v8::FunctionTemplate* templ) {
   return local_to_ptr(v8::Signature::New(isolate, ptr_to_local(templ)));
@@ -2795,4 +2803,4 @@ const char* v8__CompiledWasmModule__SourceUrl(v8::CompiledWasmModule* self,
 void v8__CompiledWasmModule__DELETE(v8::CompiledWasmModule* self) {
   delete self;
 }
-}  // extern "C"
\ No newline at end of file
+}  // extern "C"
diff --git a/src/function.rs b/src/function.rs
index 8c1d10cb..82323e35 100644
--- a/src/function.rs
+++ b/src/function.rs
@@ -42,6 +42,8 @@ extern "C" {
   ) -> *const Object;
   fn v8__Function__GetName(this: *const Function) -> *const String;
   fn v8__Function__SetName(this: *const Function, name: *const String);
+  fn v8__Function__GetScriptColumnNumber(this: *const Function) -> int;
+  fn v8__Function__GetScriptLineNumber(this: *const Function) -> int;
 
   fn v8__FunctionCallbackInfo__GetReturnValue(
     info: *const FunctionCallbackInfo,
@@ -460,4 +462,16 @@ impl Function {
   pub fn set_name(&self, name: Local<String>) {
     unsafe { v8__Function__SetName(self, &*name) }
   }
+
+  /// Get the (zero-indexed) column number of the function's definition, if available.
+  pub fn get_script_column_number(&self) -> Option<u32> {
+    let ret = unsafe { v8__Function__GetScriptColumnNumber(self) };
+    (ret >= 0).then(|| ret as u32)
+  }
+
+  /// Get the (zero-indexed) line number of the function's definition, if available.
+  pub fn get_script_line_number(&self) -> Option<u32> {
+    let ret = unsafe { v8__Function__GetScriptLineNumber(self) };
+    (ret >= 0).then(|| ret as u32)
+  }
 }
diff --git a/tests/test_api.rs b/tests/test_api.rs
index 325c39df..2071b2bc 100644
--- a/tests/test_api.rs
+++ b/tests/test_api.rs
@@ -1985,6 +1985,65 @@ fn function() {
   }
 }
 
+#[test]
+fn function_column_and_line_numbers() {
+  let _setup_guard = setup();
+  let isolate = &mut v8::Isolate::new(Default::default());
+  {
+    let scope = &mut v8::HandleScope::new(isolate);
+    let context = v8::Context::new(scope);
+    let scope = &mut v8::ContextScope::new(scope, context);
+    let source = mock_source(
+      scope,
+      "google.com",
+      r#"export function f(a, b) {
+  return a;
+}
+
+export function anotherFunctionG(a, b) {
+  return b;
+}"#,
+    );
+    let module = v8::script_compiler::compile_module(scope, source).unwrap();
+    let result =
+      module.instantiate_module(scope, unexpected_module_resolve_callback);
+    assert!(result.is_some());
+    module.evaluate(scope).unwrap();
+    assert_eq!(v8::ModuleStatus::Evaluated, module.get_status());
+
+    let namespace = module.get_module_namespace();
+    assert!(namespace.is_module_namespace_object());
+    let namespace_obj = namespace.to_object(scope).unwrap();
+
+    let f_str = v8::String::new(scope, "f").unwrap();
+    let f_function_obj: v8::Local<v8::Function> = namespace_obj
+      .get(scope, f_str.into())
+      .unwrap()
+      .try_into()
+      .unwrap();
+    // The column number is zero-indexed and indicates the position of the end of the name.
+    assert_eq!(f_function_obj.get_script_column_number(), Some(17));
+    // The line number is zero-indexed as well.
+    assert_eq!(f_function_obj.get_script_line_number(), Some(0));
+
+    let g_str = v8::String::new(scope, "anotherFunctionG").unwrap();
+    let g_function_obj: v8::Local<v8::Function> = namespace_obj
+      .get(scope, g_str.into())
+      .unwrap()
+      .try_into()
+      .unwrap();
+    assert_eq!(g_function_obj.get_script_column_number(), Some(32));
+    assert_eq!(g_function_obj.get_script_line_number(), Some(4));
+
+    let fn_template = v8::FunctionTemplate::new(scope, fn_callback);
+    let function = fn_template
+      .get_function(scope)
+      .expect("Unable to create function");
+    assert_eq!(function.get_script_column_number(), None);
+    assert_eq!(function.get_script_line_number(), None);
+  }
+}
+
 #[test]
 fn constructor() {
   let _setup_guard = setup();