fix: support typescript namespace

package.json

@@ -34,6 +34,7 @@
     "@babel/plugin-transform-template-literals": "^7.10.5",
     "@babel/preset-flow": "^7.10.4",
     "@babel/preset-react": "^7.10.4",
+    "@babel/preset-typescript": "^7.15.0",
     "@babel/traverse": "^7.11.0",
     "web-streams-polyfill": "^3.1.1",
     "abort-controller": "^3.0.0",

packages/react-refresh/src/ReactFreshBabelPlugin.js

@@ -756,8 +756,10 @@ export default function(babel, opts = {}) {
           path.traverse(HookCallsVisitor);
         },
         exit(path) {
-          const registrations = registrationsByProgramPath.get(path);
-          if (registrations === undefined) {
+          const registrations = Array.from(
+            registrationsByProgramPath.values(),
+          ).flatMap(p => p);
+          if (registrations === undefined || registrations.length === 0) {
             return;
           }
 

packages/react-refresh/src/__tests__/ReactFreshIntegration-test.js

@@ -1945,6 +1945,56 @@ describe('ReactFreshIntegration', () => {
           expect(el.textContent).toBe('CXY');
         }
       });
+
+      it('does not crash with typescript namespaces', () => {
+        if (__DEV__) {
+          const twoStepTransform = function(source) {
+            const firstStep = babel.transformSync(source, {
+              configFile: false,
+              parserOpts: {
+                plugins: ['jsx', 'typescript'],
+              },
+              plugins: ['react-refresh/babel.js'],
+            }).code;
+            const secondStep = babel.transformSync(firstStep, {
+              presets: ['@babel/preset-typescript'],
+              filename: 'file.tsx',
+            }).code;
+            return secondStep;
+          };
+
+          const code = twoStepTransform(`
+            namespace NS {
+              export const Comp = () => {
+                return <div>A</div>
+              };
+            }
+
+            function App() {
+              return <NS.Comp />
+            }
+
+            export default App;
+          `);
+          render(code);
+          expect(container.firstChild.textContent).toBe('A');
+          const patchCode = twoStepTransform(`
+            namespace NS {
+              export const Comp = () => {
+                return <div>B</div>
+              };
+            }
+
+            function App() {
+              return <NS.Comp />
+            }
+
+            export default App;
+          `);
+          patch(patchCode);
+          expect(container.firstChild.textContent).toBe('B');
+        }
+      });
     });
   }
 });