Merge pull request swiftlang#38100 from ahoppen/pr-5.5/completion-with-trailing-closure

[5.5][IDE] Show completion results if member is followed by trailing closure

Author: ahoppen

lib/Parse/ParseExpr.cpp

@@ -1170,6 +1170,19 @@ Parser::parseExprPostfixSuffix(ParserResult<Expr> Result, bool isExprBasic,
           CodeCompletion->completeDotExpr(CCExpr, /*DotLoc=*/TokLoc);
         }
         consumeToken(tok::code_complete);
+
+        // Parse and discard remaining suffixes.
+        // e.g.
+        //   closureReceiver {
+        //     baseExpr.<complete> { $0 }
+        //   }
+        // In this case, we want to consume the trailing closure because
+        // otherwise it will get parsed as a get-set clause on a variable
+        // declared by `baseExpr.<complete>` which is complete garbage.
+        bool hasBindOptional = false;
+        parseExprPostfixSuffix(makeParserResult(CCExpr), isExprBasic,
+                               periodHasKeyPathBehavior, hasBindOptional);
+
         return makeParserCodeCompletionResult(CCExpr);
       }
 

test/IDE/complete_with_trailing_closure.swift

@@ -0,0 +1,30 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-ide-test -batch-code-completion -source-filename %s -filecheck %raw-FileCheck -completion-output-dir %t
+
+public struct ItemWrapper {
+  let content: Int
+}
+
+struct MyArray {
+  func map(transform: (ItemWrapper) -> Int) {}
+}
+
+func sink(receiveValue: (MyArray) -> Void) {
+  fatalError()
+}
+
+func foo() {
+  sink { items in
+    let a = items.#^COMPLETE_WITHOUT_SPACE?check=CHECK^#map{ $0.content }
+    let b = items.#^COMPLETE_WITH_SPACE?check=CHECK^# map{ $0.content }
+    let c = items.#^COMPLETE_WITH_SPACE_AND_PARENS?check=CHECK^# map({ $0.content })
+    let d = items.#^COMPLETE_WITHOUT_SPACE_BUT_PARENS?check=CHECK^#map({ $0.content })
+    let e = items.#^COMPLETE_WITHOUT_MAP?check=CHECK^# { $0.content }
+    let f = items.#^COMPLETE_WITHOUT_MAP_BUT_PARENS?check=CHECK^# ({ $0.content })
+  }
+}
+
+// CHECK: Begin completions, 2 items
+// CHECK-DAG: Keyword[self]/CurrNominal:          self[#MyArray#];
+// CHECK-DAG: Decl[InstanceMethod]/CurrNominal/TypeRelation[Invalid]: map({#transform: (ItemWrapper) -> Int##(ItemWrapper) -> Int#})[#Void#];
+// CHECK: End completions