fixed compiler crash when unable to determine signature of function… (#321)

tomblind · web-flow · commit 92de529a5957 · 2019-01-06T07:40:01.000-07:00
* fixed compiler crash when unable to determine signature of function argument when passing a function expression

* added test
diff --git a/src/TSHelper.ts b/src/TSHelper.ts
@@ -370,7 +370,9 @@ export class TSHelper {
                     if (i >= 0) {
                         const parentSignature = checker.getResolvedSignature(signatureDeclaration.parent);
                         const parentSignatureDeclaration = parentSignature.getDeclaration();
-                        declType = checker.getTypeAtLocation(parentSignatureDeclaration.parameters[i]);
+                        if (parentSignatureDeclaration) {
+                            declType = checker.getTypeAtLocation(parentSignatureDeclaration.parameters[i]);
+                        }
                     }
                 } else if (ts.isReturnStatement(signatureDeclaration.parent)) {
                     declType = this.getContainingFunctionReturnType(signatureDeclaration.parent, checker);
diff --git a/test/unit/assignments.spec.ts b/test/unit/assignments.spec.ts
@@ -300,6 +300,20 @@ export class AssignmentTests {
         Expect(result).toBe(expectResult);
     }
 
+    @TestCase("s => s", "foo")
+    @TestCase("function(s) { return s; }", "foo")
+    @TestCase("function(this: void, s: string) { return s; }", "foo")
+    @Test("Valid function expression argument with no signature")
+    public validFunctionExpressionArgumentNoSignature(func: string, expectResult: string): void {
+        const code = `${AssignmentTests.funcAssignTestCode}
+                      const takesFunc: any = (fn: (s: string) => string) => {
+                          return (fn as any)("foo");
+                      }
+                      return takesFunc(${func});`;
+        const result = util.transpileAndExecute(code);
+        Expect(result).toBe(expectResult);
+    }
+
     @TestCase("func", "foo+func")
     @TestCase("lambda", "foo+lambda")
     @TestCase("Foo.staticMethod", "foo+staticMethod")
