Merge pull request microsoft#11228 from Microsoft/master_11192

yuit · web-flow · commit a31415d5b06e · 2016-10-05T10:55:34.000-07:00
[Master] Fix 11192
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -2183,9 +2183,14 @@ namespace ts {
                         // The specified symbol flags need to be reinterpreted as type flags
                         buildSymbolDisplay(type.symbol, writer, enclosingDeclaration, SymbolFlags.Type, SymbolFormatFlags.None, nextFlags);
                     }
-                    else if (!(flags & TypeFormatFlags.InTypeAlias) && type.flags & (TypeFlags.Anonymous | TypeFlags.UnionOrIntersection) && type.aliasSymbol &&
+                    else if (!(flags & TypeFormatFlags.InTypeAlias) && ((type.flags & TypeFlags.Anonymous && !(<AnonymousType>type).target) || type.flags & TypeFlags.UnionOrIntersection) && type.aliasSymbol &&
                         isSymbolAccessible(type.aliasSymbol, enclosingDeclaration, SymbolFlags.Type, /*shouldComputeAliasesToMakeVisible*/ false).accessibility === SymbolAccessibility.Accessible) {
-                        // Only write out inferred type with its corresponding type-alias if type-alias is visible
+                        // We emit inferred type as type-alias at the current localtion if all the following is true
+                        //      the input type is has alias symbol that is accessible
+                        //      the input type is a union, intersection or anonymous type that is fully instantiated (if not we want to keep dive into)
+                        //          e.g.: export type Bar<X, Y> = () => [X, Y];
+                        //                export type Foo<Y> = Bar<any, Y>;
+                        //                export const y = (x: Foo<string>) => 1  // we want to emit as ...x: () => [any, string])
                         const typeArguments = type.aliasTypeArguments;
                         writeSymbolTypeReference(type.aliasSymbol, typeArguments, 0, typeArguments ? typeArguments.length : 0, nextFlags);
                     }
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters1.js b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters1.js
@@ -0,0 +1,15 @@
+//// [declarationEmitTypeAliasWithTypeParameters1.ts]
+
+export type Bar<X, Y> = () => [X, Y];
+export type Foo<Y> = Bar<any, Y>;
+export const y = (x: Foo<string>) => 1
+
+//// [declarationEmitTypeAliasWithTypeParameters1.js]
+"use strict";
+exports.y = function (x) { return 1; };
+
+
+//// [declarationEmitTypeAliasWithTypeParameters1.d.ts]
+export declare type Bar<X, Y> = () => [X, Y];
+export declare type Foo<Y> = Bar<any, Y>;
+export declare const y: (x: () => [any, string]) => number;
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters1.symbols b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters1.symbols
@@ -0,0 +1,20 @@
+=== tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters1.ts ===
+
+export type Bar<X, Y> = () => [X, Y];
+>Bar : Symbol(Bar, Decl(declarationEmitTypeAliasWithTypeParameters1.ts, 0, 0))
+>X : Symbol(X, Decl(declarationEmitTypeAliasWithTypeParameters1.ts, 1, 16))
+>Y : Symbol(Y, Decl(declarationEmitTypeAliasWithTypeParameters1.ts, 1, 18))
+>X : Symbol(X, Decl(declarationEmitTypeAliasWithTypeParameters1.ts, 1, 16))
+>Y : Symbol(Y, Decl(declarationEmitTypeAliasWithTypeParameters1.ts, 1, 18))
+
+export type Foo<Y> = Bar<any, Y>;
+>Foo : Symbol(Foo, Decl(declarationEmitTypeAliasWithTypeParameters1.ts, 1, 37))
+>Y : Symbol(Y, Decl(declarationEmitTypeAliasWithTypeParameters1.ts, 2, 16))
+>Bar : Symbol(Bar, Decl(declarationEmitTypeAliasWithTypeParameters1.ts, 0, 0))
+>Y : Symbol(Y, Decl(declarationEmitTypeAliasWithTypeParameters1.ts, 2, 16))
+
+export const y = (x: Foo<string>) => 1
+>y : Symbol(y, Decl(declarationEmitTypeAliasWithTypeParameters1.ts, 3, 12))
+>x : Symbol(x, Decl(declarationEmitTypeAliasWithTypeParameters1.ts, 3, 18))
+>Foo : Symbol(Foo, Decl(declarationEmitTypeAliasWithTypeParameters1.ts, 1, 37))
+
diff --git a/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters1.types b/tests/baselines/reference/declarationEmitTypeAliasWithTypeParameters1.types
@@ -0,0 +1,22 @@
+=== tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters1.ts ===
+
+export type Bar<X, Y> = () => [X, Y];
+>Bar : Bar<X, Y>
+>X : X
+>Y : Y
+>X : X
+>Y : Y
+
+export type Foo<Y> = Bar<any, Y>;
+>Foo : () => [any, Y]
+>Y : Y
+>Bar : Bar<X, Y>
+>Y : Y
+
+export const y = (x: Foo<string>) => 1
+>y : (x: () => [any, string]) => number
+>(x: Foo<string>) => 1 : (x: () => [any, string]) => number
+>x : () => [any, string]
+>Foo : () => [any, Y]
+>1 : 1
+
diff --git a/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters1.ts b/tests/cases/compiler/declarationEmitTypeAliasWithTypeParameters1.ts
@@ -0,0 +1,5 @@
+﻿// @declaration: true
+
+export type Bar<X, Y> = () => [X, Y];
+export type Foo<Y> = Bar<any, Y>;
+export const y = (x: Foo<string>) => 1
