Move ts-node as optional dependency

index.js

@@ -32,7 +32,11 @@ class ServerlessWebpack {
       (_.has(this.serverless, 'service.custom.webpack.webpackConfig') &&
         _.endsWith(this.serverless.service.custom.webpack.webpackConfig, '.ts'))
     ) {
-      require('ts-node/register');
+      try {
+        require('ts-node/register');
+      } catch (e) {
+        throw new Error('If you want to use TypeScript with serverless-webpack, please add "ts-node" as dependency.');
+      }
     }
 
     _.assign(

index.test.js

@@ -20,6 +20,7 @@ describe('ServerlessWebpack', () => {
   let sandbox;
   let serverless;
   let ServerlessWebpack;
+  let moduleStub;
 
   before(function() {
     // Mockery might take some time to clear the cache. So add 3 seconds to the default timeout.
@@ -32,7 +33,7 @@ describe('ServerlessWebpack', () => {
     mockery.registerMock('webpack', {});
 
     ServerlessWebpack = require('./index');
-    sandbox.spy(Module, '_load');
+    moduleStub = sandbox.stub(Module, '_load');
   });
 
   beforeEach(() => {
@@ -83,6 +84,25 @@ describe('ServerlessWebpack', () => {
       expect(Module._load).to.have.been.calledOnce;
       expect(Module._load).to.have.been.calledWith('ts-node/register');
     });
+
+    it('should throw an error if config use TS but ts-node was not added as dependency', () => {
+      moduleStub.throws();
+
+      _.set(serverless, 'service.custom.webpack.webpackConfig', 'webpack.config.ts');
+
+      const badDeps = function() {
+        new ServerlessWebpack(serverless, {});
+      };
+
+      expect(badDeps).to.throw(
+        'If you want to use TypeScript with serverless-webpack, please add "ts-node" as dependency.'
+      );
+
+      expect(Module._load).to.have.been.calledOnce;
+      expect(Module._load).to.have.been.calledWith('ts-node/register');
+
+      moduleStub.reset();
+    });
   });
 
   describe('with a JS webpack configuration', () => {

lib/packExternalModules.js

@@ -442,4 +442,3 @@ module.exports = {
     });
   }
 };
-

package.json

@@ -55,8 +55,7 @@
     "glob": "^7.1.4",
     "is-builtin-module": "^3.0.0",
     "lodash": "^4.17.19",
-    "semver": "^6.2.0",
-    "ts-node": "^8.3.0"
+    "semver": "^6.2.0"
   },
   "devDependencies": {
     "babel-eslint": "^10.0.2",
@@ -80,5 +79,8 @@
   },
   "peerDependencies": {
     "webpack": ">= 3.0.0 < 6"
+  },
+  "optionalDependencies": {
+    "ts-node": ">= 8.3.0"
   }
 }

tests/validate.test.js

@@ -216,14 +216,12 @@ describe('validate', () => {
     it('should turn NodeStuffPlugin and NodeSourcePlugin plugins off by default', () => {
       const testEntry = 'testentry';
       const testConfig = {
-        entry: testEntry,
+        entry: testEntry
       };
       const testServicePath = 'testpath';
       module.serverless.config.servicePath = testServicePath;
       _.set(module.serverless.service, 'custom.webpack.config', testConfig);
-      return module
-        .validate()
-        .then(() => expect(module.webpackConfig.node).to.eql(false));
+      return module.validate().then(() => expect(module.webpackConfig.node).to.eql(false));
     });
   });
 
@@ -913,4 +911,3 @@ describe('validate', () => {
     });
   });
 });
-