Parse more types in JSDoc function() syntax

Also some cleanup from PR comments

src/compiler/checker.ts

@@ -6866,6 +6866,10 @@ namespace ts {
             }
         }
 
+        function isJSDocTypeReference(node: TypeReferenceType): node is TypeReferenceNode {
+            return node.flags & NodeFlags.JSDoc && node.kind === SyntaxKind.TypeReference;
+        }
+
         function getPrimitiveTypeFromJSDocTypeReference(node: TypeReferenceNode): Type {
             if (isIdentifier(node.typeName)) {
                 switch (node.typeName.text) {

src/compiler/parser.ts

@@ -2199,7 +2199,11 @@ namespace ts {
         }
 
         function isStartOfParameter(): boolean {
-            return token() === SyntaxKind.DotDotDotToken || isIdentifierOrPattern() || isModifierKind(token()) || token() === SyntaxKind.AtToken || token() === SyntaxKind.ThisKeyword || token() === SyntaxKind.NewKeyword;
+            return token() === SyntaxKind.DotDotDotToken ||
+                isIdentifierOrPattern() ||
+                isModifierKind(token()) ||
+                token() === SyntaxKind.AtToken || token() === SyntaxKind.ThisKeyword || token() === SyntaxKind.NewKeyword ||
+                token() === SyntaxKind.StringLiteral || token() === SyntaxKind.NumericLiteral;
         }
 
         function parseParameter(): ParameterDeclaration {

src/compiler/utilities.ts

@@ -3302,10 +3302,6 @@ namespace ts {
         return false;
     }
 
-    export function isJSDocTypeReference(node: TypeReferenceType): node is TypeReferenceNode {
-        return node.flags & NodeFlags.JSDoc && node.kind === SyntaxKind.TypeReference;
-    }
-
     /**
      * Formats an enum value as a string for debugging and debug assertions.
      */

tests/baselines/reference/jsdocFunctionType.symbols

@@ -61,3 +61,9 @@ z.length;
 >z : Symbol(z, Decl(functions.js, 26, 3))
 >length : Symbol(length, Decl(functions.js, 12, 27))
 
+/** @type {function ("a" | "b"): 1 | 2} */
+var f = function (s) { return s === "a" ? 1 : 2;  }
+>f : Symbol(f, Decl(functions.js, 30, 3))
+>s : Symbol(s, Decl(functions.js, 30, 18))
+>s : Symbol(s, Decl(functions.js, 30, 18))
+

tests/baselines/reference/jsdocFunctionType.types

@@ -68,3 +68,15 @@ z.length;
 >z : { length: number; }
 >length : number
 
+/** @type {function ("a" | "b"): 1 | 2} */
+var f = function (s) { return s === "a" ? 1 : 2;  }
+>f : (arg0: "a" | "b") => 1 | 2
+>function (s) { return s === "a" ? 1 : 2;  } : (s: "a" | "b") => 1 | 2
+>s : "a" | "b"
+>s === "a" ? 1 : 2 : 1 | 2
+>s === "a" : boolean
+>s : "a" | "b"
+>"a" : "a"
+>1 : 1
+>2 : 2
+

tests/baselines/reference/jsdocTypesInTypeAnnotations.errors.txt

@@ -1,29 +0,0 @@
-tests/cases/conformance/jsdoc/f.js(5,15): error TS2304: Cannot find name 'F'.
-tests/cases/conformance/jsdoc/f.js(5,15): error TS8010: 'types' can only be used in a .ts file.
-tests/cases/conformance/jsdoc/normal.ts(4,12): error TS7006: Parameter 'c' implicitly has an 'any' type.
-
-
-==== tests/cases/conformance/jsdoc/node.d.ts (0 errors) ====
-    declare function require(id: string): any;
-    declare var module: any, exports: any;
-    
-==== tests/cases/conformance/jsdoc/f.js (2 errors) ====
-    var F = function () {
-        this.x = 1;
-    };
-    
-    function f(p: F) { p.x; }
-                  ~
-!!! error TS2304: Cannot find name 'F'.
-                  ~
-!!! error TS8010: 'types' can only be used in a .ts file.
-    
-==== tests/cases/conformance/jsdoc/normal.ts (1 errors) ====
-    class C { p: number }
-    
-    /** @param {C} p */
-    function g(c) { return c.p }
-               ~
-!!! error TS7006: Parameter 'c' implicitly has an 'any' type.
-    
-    

tests/baselines/reference/jsweird.symbols

@@ -1,14 +0,0 @@
-=== tests/cases/conformance/jsdoc/crash.js ===
-/**
- * @param {function(new:number, string)} c crashes with correct syntax too
- * @return {number}
- */
-function sub4(c) {
->sub4 : Symbol(sub4, Decl(crash.js, 0, 0))
->c : Symbol(c, Decl(crash.js, 4, 14))
-
-    return new c('hi')
->c : Symbol(c, Decl(crash.js, 4, 14))
-}
-
-

tests/baselines/reference/jsweird.types

@@ -1,16 +0,0 @@
-=== tests/cases/conformance/jsdoc/crash.js ===
-/**
- * @param {function(new:number, string)} c crashes with correct syntax too
- * @return {number}
- */
-function sub4(c) {
->sub4 : (c: new (arg1: string) => number) => number
->c : new (arg1: string) => number
-
-    return new c('hi')
->new c('hi') : number
->c : new (arg1: string) => number
->'hi' : "hi"
-}
-
-

tests/cases/conformance/jsdoc/jsdocFunctionType.ts

@@ -33,3 +33,6 @@ class C {
 var y = id2(C);
 var z = new y(12);
 z.length;
+
+/** @type {function ("a" | "b"): 1 | 2} */
+var f = function (s) { return s === "a" ? 1 : 2;  }

tests/cases/conformance/jsdoc/jsdocTypesInTypeAnnotations.ts

@@ -1,22 +0,0 @@
-// @allowJs: true
-// @checkJs: true
-// @noEmit: true
-// @module: commonjs
-// @filename: node.d.ts
-// @noImplicitAny: true
-declare function require(id: string): any;
-declare var module: any, exports: any;
-
-// @filename: f.js
-var F = function () {
-    this.x = 1;
-};
-
-function f(p: F) { p.x; }
-
-// @filename: normal.ts
-class C { p: number }
-
-/** @param {C} p */
-function g(c) { return c.p }
-