Fix unit test (mainly function output change)

Author: armandabric

src/formatter/formatFunction.spec.ts

@@ -1,7 +1,7 @@
 import formatFunction from './formatFunction';
 
 jest.mock(
-  './formatReactElementNode.js',
+  './formatReactElementNode',
   () => (node) => `<${node.displayName} />`
 );
 
@@ -35,7 +35,7 @@ describe('formatFunction', () => {
       formatFunction(() => 1, {
         showFunctions: true,
       })
-    ).toEqual('function () {return 1;}');
+    ).toEqual('() => 1');
   });
 
   it('should use the functionValue option', () => {

src/formatter/formatPropValue.spec.tsx

@@ -44,7 +44,9 @@ describe('formatPropValue', () => {
   });
 
   it('should show the function prop value implementation if "showFunctions" option is true', () => {
-    const doThings = (a) => a * 2;
+    function doThings(a) {
+      return a * 2;
+    }
 
     expect(
       formatPropValue(doThings, false, 0, {

src/index.spec.tsx

@@ -927,10 +927,9 @@ describe('reactElementToJSXString(ReactElement)', () => {
   });
 
   it('should return the actual functions when "showFunctions" is true', () => {
-    /* eslint-disable arrow-body-style */
-    const fn = () => {
+    function fn() {
       return 'value';
-    };
+    }
 
     expect(
       reactElementToJSXString(<div fn={fn} />, {
@@ -940,10 +939,9 @@ describe('reactElementToJSXString(ReactElement)', () => {
   });
 
   it('should expose the multiline "functionValue" formatter', () => {
-    /* eslint-disable arrow-body-style */
-    const fn = () => {
+    function fn() {
       return 'value';
-    };
+    }
 
     expect(
       reactElementToJSXString(<div fn={fn} />, {