From 7bd6209fbc39c0ce63fc575f1f46505df2dd52a5 Mon Sep 17 00:00:00 2001
From: Klaus Meinhardt <klaus.meinhardt1@gmail.com>
Date: Thu, 12 Mar 2020 22:42:49 +0100
Subject: [PATCH] Don't parse duplicate JSDoc for ExpressionStatement starting
 with ParenthesizedExpression (#36289)

* don't parse JSDoc on ExpressionStatement if it starts with ParenthesizedExpression

* update test
---
 src/compiler/parser.ts                        |  4 +--
 ...pedefBeforeParenthesizedExpression.symbols | 21 +++++++++++++
 ...TypedefBeforeParenthesizedExpression.types | 31 +++++++++++++++++++
 ...docTypedefBeforeParenthesizedExpression.ts | 20 ++++++++++++
 4 files changed, 74 insertions(+), 2 deletions(-)
 create mode 100644 tests/baselines/reference/jsdocTypedefBeforeParenthesizedExpression.symbols
 create mode 100644 tests/baselines/reference/jsdocTypedefBeforeParenthesizedExpression.types
 create mode 100644 tests/cases/compiler/jsdocTypedefBeforeParenthesizedExpression.ts

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index bd59db3fe28..8434674fef3 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -1400,7 +1400,7 @@ namespace ts {
 
         function createNodeWithJSDoc(kind: SyntaxKind, pos?: number): Node {
             const node = createNode(kind, pos);
-            if (scanner.getTokenFlags() & TokenFlags.PrecedingJSDocComment) {
+            if (scanner.getTokenFlags() & TokenFlags.PrecedingJSDocComment && (kind !== SyntaxKind.ExpressionStatement || token() !== SyntaxKind.OpenParenToken)) {
                 addJSDocComment(<HasJSDoc>node);
             }
             return node;
@@ -5469,7 +5469,7 @@ namespace ts {
             // Avoiding having to do the lookahead for a labeled statement by just trying to parse
             // out an expression, seeing if it is identifier and then seeing if it is followed by
             // a colon.
-            const node = <ExpressionStatement | LabeledStatement>createNodeWithJSDoc(SyntaxKind.Unknown);
+            const node = <ExpressionStatement | LabeledStatement>createNodeWithJSDoc(token() === SyntaxKind.Identifier ? SyntaxKind.Unknown : SyntaxKind.ExpressionStatement);
             const expression = allowInAnd(parseExpression);
             if (expression.kind === SyntaxKind.Identifier && parseOptional(SyntaxKind.ColonToken)) {
                 node.kind = SyntaxKind.LabeledStatement;
diff --git a/tests/baselines/reference/jsdocTypedefBeforeParenthesizedExpression.symbols b/tests/baselines/reference/jsdocTypedefBeforeParenthesizedExpression.symbols
new file mode 100644
index 00000000000..49b1f8ffe5f
--- /dev/null
+++ b/tests/baselines/reference/jsdocTypedefBeforeParenthesizedExpression.symbols
@@ -0,0 +1,21 @@
+=== tests/cases/compiler/test.js ===
+// @ts-check
+/** @typedef {number} NotADuplicateIdentifier */
+
+(2 * 2);
+
+/** @typedef {number} AlsoNotADuplicate */
+
+(2 * 2) + 1;
+
+
+/**
+ * 
+ * @param a {NotADuplicateIdentifier}
+ * @param b {AlsoNotADuplicate}
+ */
+function makeSureTypedefsAreStillRecognized(a, b) {}
+>makeSureTypedefsAreStillRecognized : Symbol(makeSureTypedefsAreStillRecognized, Decl(test.js, 7, 12))
+>a : Symbol(a, Decl(test.js, 15, 44))
+>b : Symbol(b, Decl(test.js, 15, 46))
+
diff --git a/tests/baselines/reference/jsdocTypedefBeforeParenthesizedExpression.types b/tests/baselines/reference/jsdocTypedefBeforeParenthesizedExpression.types
new file mode 100644
index 00000000000..af858291847
--- /dev/null
+++ b/tests/baselines/reference/jsdocTypedefBeforeParenthesizedExpression.types
@@ -0,0 +1,31 @@
+=== tests/cases/compiler/test.js ===
+// @ts-check
+/** @typedef {number} NotADuplicateIdentifier */
+
+(2 * 2);
+>(2 * 2) : number
+>2 * 2 : number
+>2 : 2
+>2 : 2
+
+/** @typedef {number} AlsoNotADuplicate */
+
+(2 * 2) + 1;
+>(2 * 2) + 1 : number
+>(2 * 2) : number
+>2 * 2 : number
+>2 : 2
+>2 : 2
+>1 : 1
+
+
+/**
+ * 
+ * @param a {NotADuplicateIdentifier}
+ * @param b {AlsoNotADuplicate}
+ */
+function makeSureTypedefsAreStillRecognized(a, b) {}
+>makeSureTypedefsAreStillRecognized : (a: number, b: number) => void
+>a : number
+>b : number
+
diff --git a/tests/cases/compiler/jsdocTypedefBeforeParenthesizedExpression.ts b/tests/cases/compiler/jsdocTypedefBeforeParenthesizedExpression.ts
new file mode 100644
index 00000000000..04ae3fc406a
--- /dev/null
+++ b/tests/cases/compiler/jsdocTypedefBeforeParenthesizedExpression.ts
@@ -0,0 +1,20 @@
+// @allowJs: true
+// @noEmit: true
+
+// @filename: test.js
+// @ts-check
+/** @typedef {number} NotADuplicateIdentifier */
+
+(2 * 2);
+
+/** @typedef {number} AlsoNotADuplicate */
+
+(2 * 2) + 1;
+
+
+/**
+ * 
+ * @param a {NotADuplicateIdentifier}
+ * @param b {AlsoNotADuplicate}
+ */
+function makeSureTypedefsAreStillRecognized(a, b) {}