From 44105cc29217b04ae7bddb1ced4e8afc9e00b653 Mon Sep 17 00:00:00 2001
From: Sarath Francis <sarathfrancis90@gmail.com>
Date: Fri, 19 Jun 2026 00:47:42 -0400
Subject: [PATCH] fix(compat/toPath): keep empty segments for consecutive and
 trailing dots

toPath dropped empty path segments produced by consecutive dots or a
trailing dot, so 'a..b' became ['a', 'b'] instead of lodash's
['a', '', 'b'] and 'a.' became ['a'] instead of ['a', '']. Because
get/set/has/unset/invokeMap parse string paths through toPath, an
empty-string key in the middle of a path ('a..b' on { a: { '': ... } })
was unreachable.

Emit the empty segment when a dot is directly followed by another dot or
the end of the string, and let the leading dot fall through to the main
loop so it is still treated as a separator.
---
 src/compat/array/invokeMap.spec.ts |  2 +-
 src/compat/object/get.spec.ts      |  4 ++++
 src/compat/util/toPath.spec.ts     | 12 ++++++++++++
 src/compat/util/toPath.ts          | 11 +++++++++--
 4 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/src/compat/array/invokeMap.spec.ts b/src/compat/array/invokeMap.spec.ts
index 03d2ccde7f..f6fba8d84d 100644
--- a/src/compat/array/invokeMap.spec.ts
+++ b/src/compat/array/invokeMap.spec.ts
@@ -162,7 +162,7 @@ describe('invokeMap', () => {
     };
 
     const aEmptyDotC = invokeMap([objectWithEmptyPart], 'a..c');
-    expect(aEmptyDotC[0]).toBeUndefined();
+    expect(aEmptyDotC[0]).toBe(objectWithEmptyPart.a['']);
   });
 
   it('should match the type of lodash', () => {
diff --git a/src/compat/object/get.spec.ts b/src/compat/object/get.spec.ts
index 37a3e798a3..abbcef5776 100644
--- a/src/compat/object/get.spec.ts
+++ b/src/compat/object/get.spec.ts
@@ -164,4 +164,8 @@ describe('get', () => {
     const object = { '-0': undefined };
     expect(get(object, Object(-0), 'defaultValue')).toBe('defaultValue');
   });
+
+  it('should read empty-string keys produced by consecutive dots', () => {
+    expect(get({ a: { '': { b: 1 } } }, 'a..b')).toBe(1);
+  });
 });
diff --git a/src/compat/util/toPath.spec.ts b/src/compat/util/toPath.spec.ts
index 94b7d9b5f2..8c94ba4317 100644
--- a/src/compat/util/toPath.spec.ts
+++ b/src/compat/util/toPath.spec.ts
@@ -48,6 +48,18 @@ describe('toPath function', () => {
     expect(result).toEqual(['a', '', 'b']);
   });
 
+  it('keeps empty segments for consecutive dots', () => {
+    expect(toPath('a..b')).toEqual(['a', '', 'b']);
+    expect(toPath('a...b')).toEqual(['a', '', '', 'b']);
+    expect(toPath('..a')).toEqual(['', '', 'a']);
+    expect(toPath('a.b..c.d')).toEqual(['a', 'b', '', 'c', 'd']);
+  });
+
+  it('keeps a trailing empty segment for a trailing dot', () => {
+    expect(toPath('a.')).toEqual(['a', '']);
+    expect(toPath('a.b.')).toEqual(['a', 'b', '']);
+  });
+
   it('should match the type of lodash', () => {
     expectTypeOf(toPath).toEqualTypeOf<typeof toPathLodash>();
   });
diff --git a/src/compat/util/toPath.ts b/src/compat/util/toPath.ts
index 9f48546360..9442fdaab9 100644
--- a/src/compat/util/toPath.ts
+++ b/src/compat/util/toPath.ts
@@ -40,10 +40,10 @@ export function toPath(deepKey: any): string[] {
   let quoteChar = '';
   let bracket = false;
 
-  // Leading dot
+  // Leading dot. Record the empty segment that precedes it, but leave the dot for the
+  // main loop so it is still treated as a separator (e.g. '..a' -> ['', '', 'a']).
   if (deepKey.charCodeAt(0) === 46) {
     result.push('');
-    index++;
   }
 
   while (index < length) {
@@ -85,6 +85,13 @@ export function toPath(deepKey: any): string[] {
           result.push(key);
           key = '';
         }
+        // A dot that is directly followed by another dot or the end of the string
+        // separates an empty segment, matching lodash (e.g. 'a..b' -> ['a', '', 'b'],
+        // 'a.' -> ['a', '']).
+        const next = deepKey[index + 1];
+        if (next === undefined || next === '.') {
+          result.push('');
+        }
       } else {
         key += char;
       }