From 9ce749be6738c6ae8f9ebda74f89f922dab6c69a Mon Sep 17 00:00:00 2001
From: Khushboo Desai <desaikd@amazon.com>
Date: Tue, 4 Feb 2025 09:51:19 -0800
Subject: [PATCH] Adds location to `LazyValue` and unit tests

---
 src/lazy/value.rs | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/src/lazy/value.rs b/src/lazy/value.rs
index ebd9574f..cf1c0e06 100644
--- a/src/lazy/value.rs
+++ b/src/lazy/value.rs
@@ -8,6 +8,7 @@ use crate::{
     try_or_some_err, Annotations, Element, ExpandedValueSource, IntoAnnotatedElement, IonError,
     IonResult, IonType, SymbolRef, SymbolTable, Value,
 };
+use std::ops::Range;
 
 /// A value in a binary Ion stream whose header has been parsed but whose body (i.e. its data) has
 /// not. A `LazyValue` is immutable; its data can be read any number of times.
@@ -260,6 +261,14 @@ impl<'top, D: Decoder> LazyValue<'top, D> {
     pub fn read(&self) -> IonResult<ValueRef<'top, D>> {
         self.expanded_value.read_resolved()
     }
+
+    pub fn location(&self) -> Option<(usize, usize)> {
+        self.expanded_value.location()
+    }
+
+    pub fn range(&self) -> Option<Range<usize>> {
+        self.expanded_value.range()
+    }
 }
 
 impl<'top, D: Decoder> TryFrom<LazyValue<'top, D>> for Element {
@@ -550,4 +559,28 @@ mod tests {
         assert!(matches!(result, Err(crate::IonError::Incomplete(_))));
         Ok(())
     }
+
+    #[rstest]
+    #[case::newlines("{foo: 1, bar: 2}\r\n\n\"hello\"", (4,1))]
+    #[case::tabs("{foo: 1, bar: 2}\n\t\t\t\"hello\"", (2,4))]
+    #[case::mix_tabs_and_newlines("{foo: 1, bar: 2}\n\t\n\"hello\"", (3,1))]
+    fn location_test_for_second_tlv(
+        #[case] ion_text: &str,
+        #[case] expected_location: (usize, usize),
+    ) -> IonResult<()> {
+        let mut reader = Reader::new(v1_0::Text, ion_text)?;
+        let result1 = reader.expect_next();
+        assert!(result1.is_ok());
+        if let Ok(lazy_value1) = result1 {
+            let _val = lazy_value1.read();
+            assert_eq!(lazy_value1.location().unwrap(), (1, 1));
+        }
+        let result2 = reader.expect_next();
+        assert!(result2.is_ok());
+        if let Ok(lazy_value2) = result2 {
+            let _val = lazy_value2.read();
+            assert_eq!(lazy_value2.location().unwrap(), expected_location);
+        }
+        Ok(())
+    }
 }