test: fix typescript error

Author: devrnt

jest.config.js

@@ -1,4 +1,7 @@
 module.exports = {
   // https://github.com/testing-library/jest-native/issues/46#issuecomment-748674706
   setupFilesAfterEnv: ['<rootDir>/test/setup.ts'],
+  globals: {
+    __DEV__: 'development',
+  },
 };

src/types.ts

@@ -34,7 +34,7 @@ export type WizardValues = {
   isFirstStep: boolean;
   /** Indicate if the current step is the last step (aka no next step) */
   isLastStep: boolean;
-} | null;
+};
 
 /** Console log levels */
 export type LogLevel = 'info' | 'error' | 'warn';

src/useWizard.ts

@@ -1,5 +1,6 @@
 import * as React from 'react';
 
+import { WizardValues } from './types';
 import WizardContext from './wizardContext';
 
 const useWizard = () => {
@@ -8,7 +9,7 @@ const useWizard = () => {
   if (!context && __DEV__) {
     throw Error('Wrap your step with `Wizard`');
   } else {
-    return context;
+    return context as WizardValues;
   }
 };
 

src/wizard.tsx

@@ -79,11 +79,11 @@ const Wizard: React.FC<WizardProps> = React.memo(
           logger.log('warn', 'An invalid startIndex is passed to <Wizard>');
         }
         // Invalid header element
-        if (!React.isValidElement(header)) {
+        if (header && !React.isValidElement(header)) {
           logger.log('error', 'Invalid header passed to <Wizard>');
         }
         // Invalid footer element
-        if (!React.isValidElement(footer)) {
+        if (footer && !React.isValidElement(footer)) {
           logger.log('error', 'Invalid footer passed to <Wizard>');
         }
       }

src/wizardContext.ts

@@ -2,7 +2,7 @@ import * as React from 'react';
 
 import { WizardValues } from './types';
 
-const WizardContext = React.createContext<WizardValues>(null);
+const WizardContext = React.createContext<WizardValues | null>(null);
 WizardContext.displayName = 'WizardContext';
 
 export default WizardContext;