From 23a07b1a0f9f168c785ae9932f617aa16897337f Mon Sep 17 00:00:00 2001
From: Sean Barag <sean.barag@hulu.com>
Date: Wed, 29 May 2019 16:32:21 -0700
Subject: [PATCH] fix(lex): Allow single-word #elseif and #endif (#249)

The two-word variants `#else if` and `#end if` were already supported,
but I didn't realize the single-word versions were valid in RBI!  Now
they're valid here too.
---
 src/lexer/Lexer.ts       | 6 ++++++
 test/lexer/Lexer.test.js | 4 +++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/lexer/Lexer.ts b/src/lexer/Lexer.ts
index d61f28ca5..c823beb50 100644
--- a/src/lexer/Lexer.ts
+++ b/src/lexer/Lexer.ts
@@ -694,6 +694,12 @@ export class Lexer {
                 case "#else":
                     addToken(Lexeme.HashElse);
                     return;
+                case "#elseif":
+                    addToken(Lexeme.HashElseIf);
+                    return;
+                case "#endif":
+                    addToken(Lexeme.HashEndIf);
+                    return;
                 case "#const":
                     addToken(Lexeme.HashConst);
                     return;
diff --git a/test/lexer/Lexer.test.js b/test/lexer/Lexer.test.js
index 0c9b8ec3d..0770043cd 100644
--- a/test/lexer/Lexer.test.js
+++ b/test/lexer/Lexer.test.js
@@ -341,12 +341,14 @@ describe("lexer", () => {
         });
 
         it("reads conditional directives", () => {
-            let { tokens } = Lexer.scan("#if #else if #else #end if");
+            let { tokens } = Lexer.scan("#if #else if #elseif #else #end if #endif");
             expect(tokens.map(t => t.kind)).toEqual([
                 Lexeme.HashIf,
                 Lexeme.HashElseIf,
+                Lexeme.HashElseIf,
                 Lexeme.HashElse,
                 Lexeme.HashEndIf,
+                Lexeme.HashEndIf,
                 Lexeme.Eof,
             ]);
         });