From c764ccd17e0cf745c069b462f512b9041d6c8c90 Mon Sep 17 00:00:00 2001
From: Bharanidharan Natesan <bharaninb@users.noreply.github.com>
Date: Tue, 27 Nov 2018 17:27:20 +0530
Subject: [PATCH] fix(String literal mutator): Don't mutate export declarations

---
 .../src/mutators/StringLiteralMutator.ts      |  2 +-
 .../src/StringLiteralMutatorSpec.ts           |  5 +++++
 .../src/mutator/StringLiteralMutator.ts       |  3 +++
 .../unit/mutator/StringLiteralMutatorSpec.ts  | 20 ++++++++++++++++++-
 4 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/packages/stryker-javascript-mutator/src/mutators/StringLiteralMutator.ts b/packages/stryker-javascript-mutator/src/mutators/StringLiteralMutator.ts
index 5a25ada110..5665164b77 100644
--- a/packages/stryker-javascript-mutator/src/mutators/StringLiteralMutator.ts
+++ b/packages/stryker-javascript-mutator/src/mutators/StringLiteralMutator.ts
@@ -25,7 +25,7 @@ export default class StringLiteralMutator implements NodeMutator {
       }
 
       nodes.push(mutatedNode);
-    } else if ((!node.parent || (!types.isImportDeclaration(node.parent) && !types.isJSXAttribute(node.parent)))
+    } else if ((!node.parent || (!types.isImportDeclaration(node.parent) && !types.isExportDeclaration(node.parent) && !types.isJSXAttribute(node.parent)))
       && types.isStringLiteral(node)) {
       const mutatedNode = copy(node);
       mutatedNode.value = mutatedNode.value.length === 0 ? 'Stryker was here!' : '';
diff --git a/packages/stryker-mutator-specification/src/StringLiteralMutatorSpec.ts b/packages/stryker-mutator-specification/src/StringLiteralMutatorSpec.ts
index fe961ea9c1..4db4f3923e 100644
--- a/packages/stryker-mutator-specification/src/StringLiteralMutatorSpec.ts
+++ b/packages/stryker-mutator-specification/src/StringLiteralMutatorSpec.ts
@@ -42,6 +42,11 @@ export default function StringLiteralMutatorSpec(name: string, expectMutation: E
       expectMutation('import "foo";');
     });
 
+    it('should not mutate export statements', () => {
+      expectMutation('export * from "./foo";');
+      expectMutation('export { foo as boo } from "./foo";');
+    });
+
     it('should not mutate type declarations', () => {
       expectMutation('const a: "hello" = "hello";', 'const a: "hello" = "";');
       expectMutation('const a: Record<"id", number> = { id: 10 }');
diff --git a/packages/stryker-typescript/src/mutator/StringLiteralMutator.ts b/packages/stryker-typescript/src/mutator/StringLiteralMutator.ts
index 79508b1dec..c79c341d18 100644
--- a/packages/stryker-typescript/src/mutator/StringLiteralMutator.ts
+++ b/packages/stryker-typescript/src/mutator/StringLiteralMutator.ts
@@ -26,6 +26,9 @@ export default class StringLiteralMutator extends NodeMutator<AllStringLiterals>
   private isInvalidParent(parent: ts.Node): boolean {
     switch (parent.kind) {
       case ts.SyntaxKind.ImportDeclaration:
+      case ts.SyntaxKind.ExportDeclaration:
+      case ts.SyntaxKind.ModuleDeclaration:
+      case ts.SyntaxKind.ExternalModuleReference:
       case ts.SyntaxKind.LastTypeNode:
       case ts.SyntaxKind.JsxAttribute:
       case ts.SyntaxKind.ExpressionStatement:
diff --git a/packages/stryker-typescript/test/unit/mutator/StringLiteralMutatorSpec.ts b/packages/stryker-typescript/test/unit/mutator/StringLiteralMutatorSpec.ts
index ab60cafca6..8829e20245 100644
--- a/packages/stryker-typescript/test/unit/mutator/StringLiteralMutatorSpec.ts
+++ b/packages/stryker-typescript/test/unit/mutator/StringLiteralMutatorSpec.ts
@@ -1,5 +1,23 @@
-import { verifySpecification } from './mutatorAssertions';
+import { verifySpecification, expectMutation } from './mutatorAssertions';
 import StringLiteralMutator from '../../../src/mutator/StringLiteralMutator';
 import StringLiteralMutatorSpec from 'stryker-mutator-specification/src/StringLiteralMutatorSpec';
+import NodeMutator from '../../../src/mutator/NodeMutator';
 
 verifySpecification(StringLiteralMutatorSpec, StringLiteralMutator);
+
+describe('StringLiteralMutator - Extras', () => {
+
+  let mutator: NodeMutator;
+  before(() => {
+    mutator = new StringLiteralMutator();
+  });
+
+  it('should not mutate module declarations', () => {
+    expectMutation(mutator, 'declare module "new-foo-module";');
+    expectMutation(mutator, 'declare module "*!foo" { }');
+  });
+
+  it('should not mutate `import = require()` statements', () => {
+    expectMutation(mutator, 'import foo = require("foo");');
+  });
+});