From 0ec2911857eeba97358445582ee3484a6d81d19c Mon Sep 17 00:00:00 2001
From: Ryo Yoshida <low.ryoshida@gmail.com>
Date: Wed, 25 Jan 2023 23:47:29 +0900
Subject: [PATCH] fix: consider relative offset to fake ident token in
 expansion for completion

---
 crates/ide-completion/src/context/analysis.rs | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/crates/ide-completion/src/context/analysis.rs b/crates/ide-completion/src/context/analysis.rs
index e34824e22ea..f606d79ad20 100644
--- a/crates/ide-completion/src/context/analysis.rs
+++ b/crates/ide-completion/src/context/analysis.rs
@@ -48,7 +48,9 @@ pub(super) fn expand_and_analyze(
     // make the offset point to the start of the original token, as that is what the
     // intermediate offsets calculated in expansion always points to
     let offset = offset - relative_offset;
-    let expansion = expand(sema, original_file, speculative_file, offset, fake_ident_token);
+    let expansion =
+        expand(sema, original_file, speculative_file, offset, fake_ident_token, relative_offset);
+
     // add the relative offset back, so that left_biased finds the proper token
     let offset = expansion.offset + relative_offset;
     let token = expansion.original_file.token_at_offset(offset).left_biased()?;
@@ -67,6 +69,7 @@ fn expand(
     mut speculative_file: SyntaxNode,
     mut offset: TextSize,
     mut fake_ident_token: SyntaxToken,
+    relative_offset: TextSize,
 ) -> ExpansionResult {
     let _p = profile::span("CompletionContext::expand");
     let mut derive_ctx = None;
@@ -97,7 +100,7 @@ fn expand(
                 // successful expansions
                 (Some(actual_expansion), Some((fake_expansion, fake_mapped_token))) => {
                     let new_offset = fake_mapped_token.text_range().start();
-                    if new_offset > actual_expansion.text_range().end() {
+                    if new_offset + relative_offset > actual_expansion.text_range().end() {
                         // offset outside of bounds from the original expansion,
                         // stop here to prevent problems from happening
                         break 'expansion;
@@ -176,7 +179,7 @@ fn expand(
                 // successful expansions
                 (Some(actual_expansion), Some((fake_expansion, fake_mapped_token))) => {
                     let new_offset = fake_mapped_token.text_range().start();
-                    if new_offset > actual_expansion.text_range().end() {
+                    if new_offset + relative_offset > actual_expansion.text_range().end() {
                         // offset outside of bounds from the original expansion,
                         // stop here to prevent problems from happening
                         break 'expansion;