From 8d613c1d42da633011d7fb200ba2bae9bce8703e Mon Sep 17 00:00:00 2001
From: Trotyl <trotyl@qq.com>
Date: Sun, 18 Feb 2018 00:05:41 +0800
Subject: [PATCH] feat(compiler): allow trailing comma in array literal
 (#22277)

Allows `[1, 2, ]` syntax in angular expressions.

closes #20773

PR Close #22277
---
 packages/compiler/src/expression_parser/parser.ts     | 11 +++++++----
 .../compiler/test/expression_parser/parser_spec.ts    |  1 +
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/packages/compiler/src/expression_parser/parser.ts b/packages/compiler/src/expression_parser/parser.ts
index 958f7e1230..863c860993 100644
--- a/packages/compiler/src/expression_parser/parser.ts
+++ b/packages/compiler/src/expression_parser/parser.ts
@@ -820,11 +820,14 @@ export class _ParseAST {
 
   parseExpressionList(terminator: number): AST[] {
     const result: AST[] = [];
-    if (!this.next.isCharacter(terminator)) {
-      do {
+
+    do {
+      if (!this.next.isCharacter(terminator)) {
         result.push(this.parsePipe());
-      } while (this.consumeOptionalCharacter(chars.$COMMA));
-    }
+      } else {
+        break;
+      }
+    } while (this.consumeOptionalCharacter(chars.$COMMA));
     return result;
   }
 
diff --git a/packages/compiler/test/expression_parser/parser_spec.ts b/packages/compiler/test/expression_parser/parser_spec.ts
index 52db296380..7140f5d9bd 100644
--- a/packages/compiler/test/expression_parser/parser_spec.ts
+++ b/packages/compiler/test/expression_parser/parser_spec.ts
@@ -106,6 +106,7 @@ describe('parser', () => {
         checkAction('[]');
         checkAction('[].length');
         checkAction('[1, 2].length');
+        checkAction('[1, 2,]', '[1, 2]');
       });
 
       it('should parse map', () => {