fix(injector): ensure transient context is reset to previous one to maintain old state

ref #651

Author: marcj

packages/injector/src/injector.ts

@@ -545,9 +545,11 @@ export class Injector {
                     clear.push(`${varName} = undefined;`);
 
                     let setDestination = ``;
+                    let resetDestination = ``;
                     if (code.needsDestination) {
                         const tokenVar = compiler.reserveConst(prepared.token, 'token');
-                        setDestination = `runtimeContext.destination = { token: ${tokenVar} };`;
+                        setDestination = `const oldContext = runtimeContext.destination; runtimeContext.destination = { token: ${tokenVar} };`;
+                        resetDestination = `runtimeContext.destination = oldContext;`;
                     }
 
                     let circularCheckBefore = '';
@@ -583,6 +585,7 @@ export class Injector {
                     ${code.code}
                     ${state}.count++;
                     } finally {
+                        ${resetDestination}
                         ${state}.creating = 0;
                     }
                     ${circularCheckAfter}

packages/logger/tests/logger.spec.ts

@@ -108,7 +108,35 @@ test('scope catches late changes', () => {
     expect(logger.memory.messageStrings).toEqual(['(database) test', '(database) test2', 'test3' ]);
 });
 
-test('scoped logger', () => {
+test('scoped logger 1', () => {
+    class MyProvider {
+        constructor(public logger: ScopedLogger) {
+        }
+    }
+
+    class AnotherProvider {
+        constructor(public myProvider: MyProvider, public logger: ScopedLogger) {
+        }
+    }
+
+    {
+        const injector = Injector.from([
+            MyProvider,
+            AnotherProvider,
+            Logger, // optional base logger used by ScopedLogger
+            ScopedLogger,
+        ]);
+        const logger = injector.get(Logger);
+        expect(logger).toBeInstanceOf(Logger);
+
+        const anotherProvider = injector.get(AnotherProvider);
+        expect(anotherProvider.logger).toBeInstanceOf(Logger);
+        expect(anotherProvider.myProvider.logger.scope).toBe('MyProvider');
+        expect(anotherProvider.logger.scope).toBe('AnotherProvider');
+    }
+});
+
+test('scoped logger 2', () => {
     class MyProvider {
         constructor(public logger: ScopedLogger) {
         }