From 477e4b1a9dbc5705a14901a686a09a8644151185 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Fri, 2 Oct 2020 10:50:12 -0700
Subject: [PATCH] Fix function merged with export as namespace sourcefile
 (#40908)

Previously it crashed because the function-checking code didn't expect
a node with no parent.
---
 src/compiler/checker.ts                          |  2 +-
 .../reference/sourceFileMergeWithFunction.js     | 14 ++++++++++++++
 .../sourceFileMergeWithFunction.symbols          | 16 ++++++++++++++++
 .../reference/sourceFileMergeWithFunction.types  | 16 ++++++++++++++++
 .../salsa/sourceFileMergeWithFunction.ts         |  8 ++++++++
 5 files changed, 55 insertions(+), 1 deletion(-)
 create mode 100644 tests/baselines/reference/sourceFileMergeWithFunction.js
 create mode 100644 tests/baselines/reference/sourceFileMergeWithFunction.symbols
 create mode 100644 tests/baselines/reference/sourceFileMergeWithFunction.types
 create mode 100644 tests/cases/conformance/salsa/sourceFileMergeWithFunction.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index cf7bbed8ca5..553cb022e0c 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -32040,7 +32040,7 @@ namespace ts {
             for (const current of declarations) {
                 const node = <SignatureDeclaration | ClassDeclaration | ClassExpression>current;
                 const inAmbientContext = node.flags & NodeFlags.Ambient;
-                const inAmbientContextOrInterface = node.parent.kind === SyntaxKind.InterfaceDeclaration || node.parent.kind === SyntaxKind.TypeLiteral || inAmbientContext;
+                const inAmbientContextOrInterface = node.parent && (node.parent.kind === SyntaxKind.InterfaceDeclaration || node.parent.kind === SyntaxKind.TypeLiteral) || inAmbientContext;
                 if (inAmbientContextOrInterface) {
                     // check if declarations are consecutive only if they are non-ambient
                     // 1. ambient declarations can be interleaved
diff --git a/tests/baselines/reference/sourceFileMergeWithFunction.js b/tests/baselines/reference/sourceFileMergeWithFunction.js
new file mode 100644
index 00000000000..bd8940e92a2
--- /dev/null
+++ b/tests/baselines/reference/sourceFileMergeWithFunction.js
@@ -0,0 +1,14 @@
+//// [tests/cases/conformance/salsa/sourceFileMergeWithFunction.ts] ////
+
+//// [types.d.ts]
+declare function foo(props: any): any;
+export default foo;
+export as namespace foo;
+
+//// [foo.ts]
+/// <reference path="types.d.ts" />
+declare function foo(): any;
+
+
+//// [foo.js]
+/// <reference path="types.d.ts" />
diff --git a/tests/baselines/reference/sourceFileMergeWithFunction.symbols b/tests/baselines/reference/sourceFileMergeWithFunction.symbols
new file mode 100644
index 00000000000..11c05743387
--- /dev/null
+++ b/tests/baselines/reference/sourceFileMergeWithFunction.symbols
@@ -0,0 +1,16 @@
+=== tests/cases/conformance/salsa/foo.ts ===
+/// <reference path="types.d.ts" />
+declare function foo(): any;
+>foo : Symbol(foo, Decl(types.d.ts, 0, 0), Decl(foo.ts, 0, 0))
+
+=== tests/cases/conformance/salsa/types.d.ts ===
+declare function foo(props: any): any;
+>foo : Symbol(foo, Decl(types.d.ts, 0, 0))
+>props : Symbol(props, Decl(types.d.ts, 0, 21))
+
+export default foo;
+>foo : Symbol(foo, Decl(types.d.ts, 0, 0))
+
+export as namespace foo;
+>foo : Symbol(foo, Decl(types.d.ts, 1, 19))
+
diff --git a/tests/baselines/reference/sourceFileMergeWithFunction.types b/tests/baselines/reference/sourceFileMergeWithFunction.types
new file mode 100644
index 00000000000..0058b39c63b
--- /dev/null
+++ b/tests/baselines/reference/sourceFileMergeWithFunction.types
@@ -0,0 +1,16 @@
+=== tests/cases/conformance/salsa/foo.ts ===
+/// <reference path="types.d.ts" />
+declare function foo(): any;
+>foo : typeof import("tests/cases/conformance/salsa/types")
+
+=== tests/cases/conformance/salsa/types.d.ts ===
+declare function foo(props: any): any;
+>foo : (props: any) => any
+>props : any
+
+export default foo;
+>foo : (props: any) => any
+
+export as namespace foo;
+>foo : typeof import("tests/cases/conformance/salsa/types")
+
diff --git a/tests/cases/conformance/salsa/sourceFileMergeWithFunction.ts b/tests/cases/conformance/salsa/sourceFileMergeWithFunction.ts
new file mode 100644
index 00000000000..d96e5b4d5c1
--- /dev/null
+++ b/tests/cases/conformance/salsa/sourceFileMergeWithFunction.ts
@@ -0,0 +1,8 @@
+// @Filename: types.d.ts
+declare function foo(props: any): any;
+export default foo;
+export as namespace foo;
+
+// @Filename: foo.ts
+/// <reference path="types.d.ts" />
+declare function foo(): any;