From ae93ba1140b62b1b01182fe709bd2a4875701495 Mon Sep 17 00:00:00 2001
From: Kristiyan Kostadinov <crisbeto@abv.bg>
Date: Tue, 23 Apr 2019 17:49:31 +0200
Subject: [PATCH] fix(ivy): don't throw error when evaluating function with
 more than one statement (#30061)

Resolves functions with more than one statement to unknown dynamic values, rather than throwing an error.

PR Close #30061
---
 .../src/ngtsc/partial_evaluator/src/interpreter.ts    |  2 +-
 .../ngtsc/partial_evaluator/test/evaluator_spec.ts    | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/packages/compiler-cli/src/ngtsc/partial_evaluator/src/interpreter.ts b/packages/compiler-cli/src/ngtsc/partial_evaluator/src/interpreter.ts
index 3d5698c333..4d2300f30f 100644
--- a/packages/compiler-cli/src/ngtsc/partial_evaluator/src/interpreter.ts
+++ b/packages/compiler-cli/src/ngtsc/partial_evaluator/src/interpreter.ts
@@ -421,7 +421,7 @@ export class StaticInterpreter {
 
     const body = fn.body;
     if (body.length !== 1 || !ts.isReturnStatement(body[0])) {
-      throw new Error('Function body must have a single return statement only.');
+      return DynamicValue.fromUnknown(node);
     }
     const ret = body[0] as ts.ReturnStatement;
 
diff --git a/packages/compiler-cli/src/ngtsc/partial_evaluator/test/evaluator_spec.ts b/packages/compiler-cli/src/ngtsc/partial_evaluator/test/evaluator_spec.ts
index 7a48703160..30c5b608fe 100644
--- a/packages/compiler-cli/src/ngtsc/partial_evaluator/test/evaluator_spec.ts
+++ b/packages/compiler-cli/src/ngtsc/partial_evaluator/test/evaluator_spec.ts
@@ -356,6 +356,17 @@ describe('ngtsc metadata', () => {
     expect(id.text).toEqual('Target');
   });
 
+  it('should resolve functions with more than one statement to an unknown value', () => {
+    const value = evaluate(`function foo(bar) { const b = bar; return b; }`, 'foo("test")');
+
+    if (!(value instanceof DynamicValue)) {
+      return fail(`Should have resolved to a DynamicValue`);
+    }
+
+    expect(value.isFromUnknown()).toBe(true);
+    expect((value.node as ts.CallExpression).expression.getText()).toBe('foo');
+  });
+
   describe('(visited file tracking)', () => {
     it('should track each time a source file is visited', () => {
       const visitedFilesSpy = jasmine.createSpy('visitedFilesCb');