Fix TypeScript definitions generation when no helpers configured

example-esm/steps.d.ts

@@ -1,11 +1,9 @@
 /// <reference types='codeceptjs' />
+type CustomHelper = InstanceType<typeof import('./helpers/CustomHelper.js').default>;
 
 declare namespace CodeceptJS {
-  interface SupportObject {
-    I: I
-    current: any
-  }
-
+  interface SupportObject { I: I, current: any }
+  interface Methods extends CustomHelper, FileSystem, REST {}
   interface I extends WithTranslation<Methods> {}
   namespace Translation {
     interface Actions {}

examples/steps.d.ts

@@ -0,0 +1,15 @@
+/// <reference types='codeceptjs' />
+type steps_file = typeof import('./custom_steps.js')['default'];
+type Smth = typeof import('./pages/Smth.js')['default'];
+type loginPage = typeof import('./pages/Login.js')['default'];
+type signinFragment = typeof import('./fragments/Signin.js')['default'];
+type User = InstanceType<typeof import('./user_helper.js').default>;
+
+declare namespace CodeceptJS {
+  interface SupportObject { I: I, current: any, Smth: Smth, loginPage: loginPage, signinFragment: signinFragment }
+  interface Methods extends Playwright, REST, User {}
+  interface I extends ReturnType<steps_file>, WithTranslation<Methods> {}
+  namespace Translation {
+    interface Actions {}
+  }
+}

lib/command/definitions.js

@@ -41,7 +41,7 @@ const getDefinitionsFileContent = ({ hasCustomHelper, hasCustomStepsFile, helper
 
   const importPathsFragment = importPaths.join('\n')
   const supportObjectsTypeFragment = convertMapToType(supportObject)
-  const methodsTypeFragment = helperNames.length > 0 ? `interface Methods extends ${helperNames.join(', ')} {}` : ''
+  const methodsTypeFragment = helperNames.length > 0 ? `interface Methods extends ${helperNames.join(', ')} {}` : 'interface Methods {}'
   const translatedActionsFragment = JSON.stringify(translations.vocabulary.actions, null, 2)
 
   return generateDefinitionsContent({

test/data/sandbox/configs/custom-helper-esm/steps.d.ts

@@ -0,0 +1,11 @@
+/// <reference types='codeceptjs' />
+type MyHelper = InstanceType<typeof import('./myhelper_helper.js').default>;
+
+declare namespace CodeceptJS {
+  interface SupportObject { I: I, current: any }
+  interface Methods extends FileSystem, MyHelper {}
+  interface I extends WithTranslation<Methods> {}
+  namespace Translation {
+    interface Actions {}
+  }
+}

test/data/sandbox/configs/definitions/codecept.no-helpers.js

@@ -0,0 +1,10 @@
+export const config = {
+  tests: './*_test.js',
+  timeout: 10000,
+  output: './output',
+  helpers: {},
+  include: {},
+  bootstrap: false,
+  mocha: {},
+  name: 'sandbox-no-helpers',
+};

test/runner/definitions_test.js

@@ -283,6 +283,22 @@ describe('Definitions', function () {
       done()
     })
   })
+
+  it('def should create definition file with empty Methods interface when no helpers configured', done => {
+    exec(`${runner} def --config ${codecept_dir}/codecept.no-helpers.js`, (err, stdout) => {
+      stdout.should.include('Definitions were generated in steps.d.ts')
+      const types = typesFrom(`${codecept_dir}/steps.d.ts`)
+      types.should.be.valid
+
+      const definitionFile = types.getSourceFileOrThrow(`${codecept_dir}/steps.d.ts`)
+      const fileContent = definitionFile.getFullText()
+      fileContent.should.include('interface Methods {}')
+      fileContent.should.include('interface I extends WithTranslation<Methods>')
+
+      assert(!err)
+      done()
+    })
+  })
 })
 
 /**