Reuse greatest_lower_bound in get_scope_for_token

src/hermes.rs

@@ -3,9 +3,9 @@ use crate::encoder::{encode, Encodable};
 use crate::errors::{Error, Result};
 use crate::jsontypes::{FacebookScopeMapping, FacebookSources, RawSourceMap};
 use crate::types::{DecodedMap, RewriteOptions, SourceMap};
+use crate::utils::greatest_lower_bound;
 use crate::vlq::parse_vlq_segment_into;
 use crate::Token;
-use std::cmp::Ordering;
 use std::io::{Read, Write};
 use std::ops::{Deref, DerefMut};
 
@@ -104,24 +104,12 @@ impl SourceMapHermes {
 
         // Find the closest mapping, just like here:
         // https://github.com/facebook/metro/blob/63b523eb20e7bdf62018aeaf195bb5a3a1a67f36/packages/metro-symbolicate/src/SourceMetadataMapConsumer.js#L204-L231
-        let mapping =
-            function_map
-                .mappings
-                .binary_search_by(|o| match o.line.cmp(&token.get_src_line()) {
-                    Ordering::Equal => o.column.cmp(&token.get_src_col()),
-                    x => x,
-                });
-        let name_index = function_map
-            .mappings
-            .get(match mapping {
-                Ok(a) => a,
-                Err(a) => a.saturating_sub(1),
-            })?
-            .name_index;
-
+        let mapping = greatest_lower_bound(&function_map.mappings, &token.get_src(), |o| {
+            (o.line, o.column)
+        })?;
         function_map
             .names
-            .get(name_index as usize)
+            .get(mapping.name_index as usize)
             .map(|n| n.as_str())
     }
 

src/types.rs

@@ -10,7 +10,7 @@ use crate::encoder::encode;
 use crate::errors::{Error, Result};
 use crate::hermes::SourceMapHermes;
 use crate::sourceview::SourceView;
-use crate::utils::find_common_prefix;
+use crate::utils::{find_common_prefix, greatest_lower_bound};
 
 /// Controls the `SourceMap::rewrite` behavior
 ///
@@ -1053,20 +1053,3 @@ impl SourceMapSection {
         self.map = sm.map(Box::new);
     }
 }
-
-fn greatest_lower_bound<'a, T, K: Ord, F: Fn(&'a T) -> K>(
-    slice: &'a [T],
-    key: &K,
-    map: F,
-) -> Option<&'a T> {
-    match slice.binary_search_by_key(key, map) {
-        Ok(index) => Some(&slice[index]),
-        Err(index) => {
-            if index > 0 {
-                Some(&slice[index - 1])
-            } else {
-                None
-            }
-        }
-    }
-}

src/utils.rs

@@ -144,6 +144,23 @@ pub fn make_relative_path(base: &str, target: &str) -> String {
     }
 }
 
+pub fn greatest_lower_bound<'a, T, K: Ord, F: Fn(&'a T) -> K>(
+    slice: &'a [T],
+    key: &K,
+    map: F,
+) -> Option<&'a T> {
+    match slice.binary_search_by_key(key, map) {
+        Ok(index) => Some(&slice[index]),
+        Err(index) => {
+            if index > 0 {
+                Some(&slice[index - 1])
+            } else {
+                None
+            }
+        }
+    }
+}
+
 #[test]
 fn test_is_abs_path() {
     assert!(is_abs_path("C:\\foo.txt"));