From ba72acb5527fa8fb752184da5b2f864d6b140cf9 Mon Sep 17 00:00:00 2001
From: Ayaz Hafiz <ayazhafiz@lyft.com>
Date: Sat, 8 Feb 2020 20:24:56 -0800
Subject: [PATCH] fix(compiler): do not recurse to find static symbols of same
 module

To the create symbols of a module, the static symbol resolver first gets
all the symbols loaded in the module by an export statement. For `export
* from './module'`-like statements, all symbols from `./module` must be
loaded. In cases where the exporting module is actually the same module
that the export statement is in, this causes an unbounded recursive
resolution of the same module.

Exports of the same module are not needed, as their symbols will be
resolved when the symbols in the module metadata's `metadata` key is
explored.

This commit resolves the unbounded recursion by loading exporting
modules only if they differ from the module currently being resolved.

Closes https://github.com/angular/vscode-ng-language-service/issues/593
---
 packages/compiler/src/aot/static_symbol_resolver.ts |  4 ++--
 .../test/aot/static_symbol_resolver_spec.ts         | 13 +++++++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/packages/compiler/src/aot/static_symbol_resolver.ts b/packages/compiler/src/aot/static_symbol_resolver.ts
index 74ff525e7db000..8ec20dcd2ac13e 100644
--- a/packages/compiler/src/aot/static_symbol_resolver.ts
+++ b/packages/compiler/src/aot/static_symbol_resolver.ts
@@ -313,9 +313,9 @@ export class StaticSymbolResolver {
             }
           });
         } else {
-          // handle the symbols via export * directives.
+          // Handle the symbols loaded by 'export *' directives.
           const resolvedModule = this.resolveModule(moduleExport.from, filePath);
-          if (resolvedModule) {
+          if (resolvedModule && resolvedModule !== filePath) {
             const nestedExports = this.getSymbolsOf(resolvedModule);
             nestedExports.forEach((targetSymbol) => {
               const sourceSymbol = this.getStaticSymbol(filePath, targetSymbol.name);
diff --git a/packages/compiler/test/aot/static_symbol_resolver_spec.ts b/packages/compiler/test/aot/static_symbol_resolver_spec.ts
index 9d410d829f6584..41faab8ab3b67e 100644
--- a/packages/compiler/test/aot/static_symbol_resolver_spec.ts
+++ b/packages/compiler/test/aot/static_symbol_resolver_spec.ts
@@ -103,6 +103,19 @@ describe('StaticSymbolResolver', () => {
         .toBe(symbolResolver.getStaticSymbol('/tmp/src/export.ts', 'exportedObj', ['someMember']));
   });
 
+  it('should not explore re-exports of the same module', () => {
+    init({
+      '/tmp/src/test.ts': `
+        export * from './test';
+
+        export const testValue = 10;
+      `,
+    });
+
+    const symbols = symbolResolver.getSymbolsOf('/tmp/src/test.ts');
+    expect(symbols).toEqual([symbolResolver.getStaticSymbol('/tmp/src/test.ts', 'testValue')]);
+  });
+
   it('should use summaries in resolveSymbol and prefer them over regular metadata', () => {
     const symbolA = symbolCache.get('/test.ts', 'a');
     const symbolB = symbolCache.get('/test.ts', 'b');