From f012ce0d18b19a8dfc815498108b9b5fdde26b46 Mon Sep 17 00:00:00 2001
From: Max Prokopiev <maxprokopiev@github.com>
Date: Fri, 16 Feb 2024 14:43:35 +0100
Subject: [PATCH] [ruby/prism] Fix lexing of `foo!` when it's a first thing to
 parse

https://github.com/ruby/prism/commit/7597aca76a
---
 lib/prism/translation/parser/lexer.rb             |  2 +-
 .../fixtures/single_method_call_with_bang.txt     |  1 +
 .../snapshots/single_method_call_with_bang.txt    | 15 +++++++++++++++
 3 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 test/prism/fixtures/single_method_call_with_bang.txt
 create mode 100644 test/prism/snapshots/single_method_call_with_bang.txt

diff --git a/lib/prism/translation/parser/lexer.rb b/lib/prism/translation/parser/lexer.rb
index 6d3321b945d965..5c993cfab8167a 100644
--- a/lib/prism/translation/parser/lexer.rb
+++ b/lib/prism/translation/parser/lexer.rb
@@ -289,7 +289,7 @@ def to_a
                 index += 1
               end
             when :tFID
-              if tokens[-1][0] == :kDEF
+              if !tokens.empty? && tokens[-1][0] == :kDEF
                 type = :tIDENTIFIER
               end
             end
diff --git a/test/prism/fixtures/single_method_call_with_bang.txt b/test/prism/fixtures/single_method_call_with_bang.txt
new file mode 100644
index 00000000000000..929efb30534598
--- /dev/null
+++ b/test/prism/fixtures/single_method_call_with_bang.txt
@@ -0,0 +1 @@
+foo!
diff --git a/test/prism/snapshots/single_method_call_with_bang.txt b/test/prism/snapshots/single_method_call_with_bang.txt
new file mode 100644
index 00000000000000..4c68e0adac9e4c
--- /dev/null
+++ b/test/prism/snapshots/single_method_call_with_bang.txt
@@ -0,0 +1,15 @@
+@ ProgramNode (location: (1,0)-(1,4))
+├── locals: []
+└── statements:
+    @ StatementsNode (location: (1,0)-(1,4))
+    └── body: (length: 1)
+        └── @ CallNode (location: (1,0)-(1,4))
+            ├── flags: ignore_visibility
+            ├── receiver: ∅
+            ├── call_operator_loc: ∅
+            ├── name: :foo!
+            ├── message_loc: (1,0)-(1,4) = "foo!"
+            ├── opening_loc: ∅
+            ├── arguments: ∅
+            ├── closing_loc: ∅
+            └── block: ∅