From 5e1baffee00e027260478d0b622b8c676bb5ff8d Mon Sep 17 00:00:00 2001
From: kingwl <805037171@163.com>
Date: Wed, 6 Dec 2017 12:52:22 +0800
Subject: [PATCH] fix decorator format with first parameter

---
 src/services/formatting/rules.ts                     | 11 ++++++++++-
 .../fourslash/formattingParameterWithDecorator.ts    | 12 ++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)
 create mode 100644 tests/cases/fourslash/formattingParameterWithDecorator.ts

diff --git a/src/services/formatting/rules.ts b/src/services/formatting/rules.ts
index 8214ffd6f2ddb..6e62a3ef023f2 100644
--- a/src/services/formatting/rules.ts
+++ b/src/services/formatting/rules.ts
@@ -198,7 +198,7 @@ namespace ts.formatting {
                 RuleAction.Delete),
 
             // decorators
-            rule("SpaceBeforeAt", anyToken, SyntaxKind.AtToken, [isNonJsxSameLineTokenContext], RuleAction.Space),
+            rule("SpaceBeforeAt", anyToken, SyntaxKind.AtToken, [isNonJsxSameLineTokenContext, isNotDecoratorWithFirstParameterContext], RuleAction.Space),
             rule("NoSpaceAfterAt", SyntaxKind.AtToken, anyToken, [isNonJsxSameLineTokenContext], RuleAction.Delete),
             // Insert space after @ in decorator
             rule("SpaceAfterDecorator",
@@ -720,4 +720,13 @@ namespace ts.formatting {
     function isNonNullAssertionContext(context: FormattingContext): boolean {
         return context.contextNode.kind === SyntaxKind.NonNullExpression;
     }
+
+    function isDecoratorWithFirstParameterContext(context: FormattingContext): boolean {
+        return context.currentTokenSpan.kind === SyntaxKind.OpenParenToken && context.nextTokenParent.kind === SyntaxKind.Decorator &&
+            context.nextTokenParent.parent && context.nextTokenParent.parent.kind === SyntaxKind.Parameter;
+    }
+
+    function isNotDecoratorWithFirstParameterContext(context: FormattingContext): boolean {
+        return !isDecoratorWithFirstParameterContext(context);
+    }
 }
diff --git a/tests/cases/fourslash/formattingParameterWithDecorator.ts b/tests/cases/fourslash/formattingParameterWithDecorator.ts
new file mode 100644
index 0000000000000..865df621dda79
--- /dev/null
+++ b/tests/cases/fourslash/formattingParameterWithDecorator.ts
@@ -0,0 +1,12 @@
+/// <reference path='fourslash.ts' />
+
+/////*1*/function (@foo a: any, @bar b: any) { }
+/////*2*/class Test { constructor(@foo props: any, @bar b: any) { } }
+
+format.document();
+
+goTo.marker('1');
+verify.currentLineContentIs('function (@foo a: any, @bar b: any) { }');
+
+goTo.marker('2');
+verify.currentLineContentIs('class Test { constructor(@foo props: any, @bar b: any) { } }');
\ No newline at end of file