use CompilerHost.realpath to resolve actual location for symlinks

tests/baselines/reference/moduleResolutionWithSymlinks.js

@@ -0,0 +1,37 @@
+//// [tests/cases/compiler/moduleResolutionWithSymlinks.ts] ////
+
+//// [index.ts]
+
+export class MyClass{}
+
+//// [index.ts]
+import {MyClass} from "library-a";
+export { MyClass as MyClass2 }
+
+//// [app.ts]
+import { MyClass } from "./library-a";
+import { MyClass2 } from "./library-b";
+
+let x: MyClass;
+let y: MyClass2;
+x = y;
+y = x;
+
+//// [index.js]
+"use strict";
+var MyClass = (function () {
+    function MyClass() {
+    }
+    return MyClass;
+}());
+exports.MyClass = MyClass;
+//// [index.js]
+"use strict";
+var library_a_1 = require("library-a");
+exports.MyClass2 = library_a_1.MyClass;
+//// [app.js]
+"use strict";
+var x;
+var y;
+x = y;
+y = x;

tests/baselines/reference/moduleResolutionWithSymlinks.symbols

@@ -0,0 +1,36 @@
+=== /src/app.ts ===
+import { MyClass } from "./library-a";
+>MyClass : Symbol(MyClass, Decl(app.ts, 0, 8))
+
+import { MyClass2 } from "./library-b";
+>MyClass2 : Symbol(MyClass2, Decl(app.ts, 1, 8))
+
+let x: MyClass;
+>x : Symbol(x, Decl(app.ts, 3, 3))
+>MyClass : Symbol(MyClass, Decl(app.ts, 0, 8))
+
+let y: MyClass2;
+>y : Symbol(y, Decl(app.ts, 4, 3))
+>MyClass2 : Symbol(MyClass2, Decl(app.ts, 1, 8))
+
+x = y;
+>x : Symbol(x, Decl(app.ts, 3, 3))
+>y : Symbol(y, Decl(app.ts, 4, 3))
+
+y = x;
+>y : Symbol(y, Decl(app.ts, 4, 3))
+>x : Symbol(x, Decl(app.ts, 3, 3))
+
+=== /src/library-a/index.ts ===
+
+export class MyClass{}
+>MyClass : Symbol(MyClass, Decl(index.ts, 0, 0))
+
+=== /src/library-b/index.ts ===
+import {MyClass} from "library-a";
+>MyClass : Symbol(MyClass, Decl(index.ts, 0, 8))
+
+export { MyClass as MyClass2 }
+>MyClass : Symbol(MyClass2, Decl(index.ts, 1, 8))
+>MyClass2 : Symbol(MyClass2, Decl(index.ts, 1, 8))
+

tests/baselines/reference/moduleResolutionWithSymlinks.trace.json

@@ -0,0 +1,32 @@
+[
+    "======== Resolving module './library-a' from '/src/app.ts'. ========",
+    "Module resolution kind is not specified, using 'NodeJs'.",
+    "Loading module as file / folder, candidate module location '/src/library-a'.",
+    "File '/src/library-a.ts' does not exist.",
+    "File '/src/library-a.tsx' does not exist.",
+    "File '/src/library-a.d.ts' does not exist.",
+    "File '/src/library-a/package.json' does not exist.",
+    "File '/src/library-a/index.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/src/library-a/index.ts', result '/src/library-a/index.ts'",
+    "======== Module name './library-a' was successfully resolved to '/src/library-a/index.ts'. ========",
+    "======== Resolving module './library-b' from '/src/app.ts'. ========",
+    "Module resolution kind is not specified, using 'NodeJs'.",
+    "Loading module as file / folder, candidate module location '/src/library-b'.",
+    "File '/src/library-b.ts' does not exist.",
+    "File '/src/library-b.tsx' does not exist.",
+    "File '/src/library-b.d.ts' does not exist.",
+    "File '/src/library-b/package.json' does not exist.",
+    "File '/src/library-b/index.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/src/library-b/index.ts', result '/src/library-b/index.ts'",
+    "======== Module name './library-b' was successfully resolved to '/src/library-b/index.ts'. ========",
+    "======== Resolving module 'library-a' from '/src/library-b/index.ts'. ========",
+    "Module resolution kind is not specified, using 'NodeJs'.",
+    "Loading module 'library-a' from 'node_modules' folder.",
+    "File '/src/library-b/node_modules/library-a.ts' does not exist.",
+    "File '/src/library-b/node_modules/library-a.tsx' does not exist.",
+    "File '/src/library-b/node_modules/library-a.d.ts' does not exist.",
+    "File '/src/library-b/node_modules/library-a/package.json' does not exist.",
+    "File '/src/library-b/node_modules/library-a/index.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/src/library-b/node_modules/library-a/index.ts', result '/src/library-a/index.ts'",
+    "======== Module name 'library-a' was successfully resolved to '/src/library-a/index.ts'. ========"
+]

tests/baselines/reference/moduleResolutionWithSymlinks.types

@@ -0,0 +1,38 @@
+=== /src/app.ts ===
+import { MyClass } from "./library-a";
+>MyClass : typeof MyClass
+
+import { MyClass2 } from "./library-b";
+>MyClass2 : typeof MyClass
+
+let x: MyClass;
+>x : MyClass
+>MyClass : MyClass
+
+let y: MyClass2;
+>y : MyClass
+>MyClass2 : MyClass
+
+x = y;
+>x = y : MyClass
+>x : MyClass
+>y : MyClass
+
+y = x;
+>y = x : MyClass
+>y : MyClass
+>x : MyClass
+
+=== /src/library-a/index.ts ===
+
+export class MyClass{}
+>MyClass : MyClass
+
+=== /src/library-b/index.ts ===
+import {MyClass} from "library-a";
+>MyClass : typeof MyClass
+
+export { MyClass as MyClass2 }
+>MyClass : typeof MyClass
+>MyClass2 : typeof MyClass
+

tests/cases/compiler/moduleResolutionWithSymlinks.ts

@@ -0,0 +1,20 @@
+// @module: commonjs
+// @noImplicitReferences: true
+// @traceResolution: true
+
+// @filename: /src/library-a/index.ts
+// @symlink: /src/library-b/node_modules/library-a/index.ts
+export class MyClass{}
+
+// @filename: /src/library-b/index.ts
+import {MyClass} from "library-a";
+export { MyClass as MyClass2 }
+
+// @filename: /src/app.ts
+import { MyClass } from "./library-a";
+import { MyClass2 } from "./library-b";
+
+let x: MyClass;
+let y: MyClass2;
+x = y;
+y = x;