breaking: Migrate codebase to typescript

src/__tests__/to-contain-element.tsx

@@ -48,20 +48,20 @@ test('.toContainElement negative test cases', () => {
   expect(() => expect(grandparent).toContainElement(nonExistantElement)).toThrow();
   expect(() => expect(nonExistantElement).toContainElement(nonExistantElement)).toThrow();
 
-  // @ts-expect-error intentionally passing incorrec type
+  // @ts-expect-error intentionally passing incorrect type
   expect(() => expect(nonExistantElement).toContainElement(fakeElement)).toThrow();
   expect(() => expect(fakeElement).toContainElement(nonExistantElement)).toThrow();
   expect(() => expect(fakeElement).not.toContainElement(nonExistantElement)).toThrow();
   expect(() => expect(fakeElement).toContainElement(grandparent)).toThrow();
 
-  // @ts-expect-error intentionally passing incorrec type
+  // @ts-expect-error intentionally passing incorrect type
   expect(() => expect(grandparent).toContainElement(fakeElement)).toThrow();
 
-  // @ts-expect-error intentionally passing incorrec type
+  // @ts-expect-error intentionally passing incorrect type
   expect(() => expect(fakeElement).toContainElement(fakeElement)).toThrow();
   expect(() => expect(grandparent).not.toContainElement(child)).toThrow();
   expect(() => expect(grandparent).not.toContainElement(textElement)).toThrow();
 
-  // @ts-expect-error intentionally passing incorrec type
+  // @ts-expect-error intentionally passing incorrect type
   expect(() => expect(grandparent).not.toContainElement(undefined)).toThrow();
 });

src/to-be-disabled.ts

@@ -54,7 +54,7 @@ export function toBeDisabled(this: jest.MatcherContext, element: ReactTestInstan
 export function toBeEnabled(this: jest.MatcherContext, element: ReactTestInstance) {
   checkReactElement(element, toBeEnabled, this);
 
-  const isEnabled = !(isElementDisabled(element) || isAncestorDisabled(element));
+  const isEnabled = !isElementDisabled(element);
 
   return {
     pass: isEnabled,

src/to-have-text-content.ts

@@ -7,15 +7,14 @@ function collectNormalizedText(element: ReactTestInstance) {
   return normalize(childrenText);
 }
 
-function collectChildrenText(element: string | ReactTestInstance): string[] {
+function collectChildrenText(element: ReactTestInstance | string): string[] {
   if (typeof element === 'string') return [element];
-  if (!element || !element.children) return [''];
+  if (!element || !element.children) return [];
 
-  let result: string[] = [];
-
-  for (const child of element.children) {
-    result = result.concat(collectChildrenText(child));
-  }
+  const result: string[] = [];
+  element.children.forEach((child) => {
+    result.push(...collectChildrenText(child));
+  });
 
   return result;
 }

src/utils.ts

@@ -26,11 +26,7 @@ const VALID_ELEMENTS = [
 ];
 
 class ReactElementTypeError extends Error {
-  constructor(
-    received: ReactTestInstance | null | undefined,
-    matcherFn: jest.CustomMatcher,
-    context: jest.MatcherContext,
-  ) {
+  constructor(received: unknown, matcherFn: jest.CustomMatcher, context: jest.MatcherContext) {
     super();
 
     /* istanbul ignore next */
@@ -43,6 +39,7 @@ class ReactElementTypeError extends Error {
     } catch (e) {
       // Deliberately empty.
     }
+
     /* istanbul ignore next */
     this.message = [
       matcherHint(`${context.isNot ? '.not' : ''}.${matcherFn.name}`, 'received', ''),
@@ -62,7 +59,7 @@ function checkReactElement(
     throw new ReactElementTypeError(element, matcherFn, context);
   }
 
-  // @ts-expect-error not sure where to get this fiber property
+  // @ts-expect-error internal _fiber property of ReactTestInstance
   if (!element._fiber && !VALID_ELEMENTS.includes(element.type.toString())) {
     throw new ReactElementTypeError(element, matcherFn, context);
   }
@@ -73,8 +70,11 @@ function getType({ type }: ReactTestInstance) {
   return type.displayName || type.name || type;
 }
 
-function printElement(element: ReactTestInstance | null | undefined) {
-  if (!element) return '';
+function printElement(element: ReactTestInstance | null) {
+  if (element == null) {
+    return 'null';
+  }
+
   return `  ${prettyFormat(
     { props: element.props },
     {
@@ -152,5 +152,4 @@ export {
   normalize,
   isEmpty,
   printElement,
-  display,
 };