feat: Matches toBe(null) and toEqual(null) in addition to toBeNull() in prefer-document (#153)

Fixes #152

Author: julienw

docs/rules/prefer-in-document.md

@@ -15,6 +15,10 @@ expect(wrapper.queryByText("foo")).toHaveLength(1);
 expect(queryByText("foo")).toHaveLength(0);
 expect(queryByText("foo")).toBeNull();
 expect(queryByText("foo")).not.toBeNull();
+expect(queryByText("foo")).toBe(null);
+expect(queryByText("foo")).not.toBe(null);
+expect(queryByText("foo")).toEqual(null);
+expect(queryByText("foo")).not.toEqual(null);
 expect(queryByText("foo")).toBeDefined();
 expect(queryByText("foo")).not.toBeDefined();
 

src/__tests__/lib/rules/prefer-in-document.js

@@ -82,6 +82,8 @@ const valid = [
   `import {NUM_BUTTONS} from "./foo";
      expect(screen.getByText('foo')).toHaveLength(NUM_BUTTONS)`,
   `expect(screen.getAllByText("foo")).toHaveLength(getLength())`,
+  `expect(screen.getAllByText("foo")).toBe(foo)`,
+  `expect(screen.getAllByText("foo")).toEqual(foo)`,
 ];
 const invalid = [
   invalidCase(
@@ -239,6 +241,22 @@ const invalid = [
     `expect(queryByText('foo')) .not .toBeNull()`,
     `expect(queryByText('foo')).toBeInTheDocument()`
   ),
+  invalidCase(
+    `expect(queryByText('foo')).toBe(null)`,
+    `expect(queryByText('foo')).not.toBeInTheDocument()`
+  ),
+  invalidCase(
+    `expect(queryByText('foo')).not.toBe(null)`,
+    `expect(queryByText('foo')).toBeInTheDocument()`
+  ),
+  invalidCase(
+    `expect(queryByText('foo')).toEqual(null)`,
+    `expect(queryByText('foo')).not.toBeInTheDocument()`
+  ),
+  invalidCase(
+    `expect(queryByText('foo')).not.toEqual(null)`,
+    `expect(queryByText('foo')).toBeInTheDocument()`
+  ),
   invalidCase(
     `expect(queryByText('foo')).toBeDefined()`,
     `expect(queryByText('foo')).toBeInTheDocument()`

src/rules/prefer-in-document.js

@@ -3,6 +3,8 @@
  * @author Anton Niklasson
  */
 
+/*eslint complexity: ["error", {"max": 20}]*/
+
 import { queries } from "../queries";
 import { getAssignmentForIdentifier } from "../assignment-ast";
 
@@ -24,16 +26,22 @@ export const meta = {
 function isAntonymMatcher(matcherNode, matcherArguments) {
   return (
     matcherNode.name === "toBeNull" ||
+    usesToBeOrToEqualWithNull(matcherNode, matcherArguments) ||
     usesToHaveLengthZero(matcherNode, matcherArguments)
   );
 }
 
+function usesToBeOrToEqualWithNull(matcherNode, matcherArguments) {
+  return (matcherNode.name === "toBe" || matcherNode.name === "toEqual") &&
+    matcherArguments[0].value === null;
+}
+
 function usesToHaveLengthZero(matcherNode, matcherArguments) {
   return matcherNode.name === "toHaveLength" && matcherArguments[0].value === 0;
 }
 
 export const create = (context) => {
-  const alternativeMatchers = /(toHaveLength|toBeDefined|toBeNull)/;
+  const alternativeMatchers = /^(toHaveLength|toBeDefined|toBeNull|toBe|toEqual)$/;
   function getLengthValue(matcherArguments) {
     let lengthValue;
 
@@ -79,6 +87,13 @@ export const create = (context) => {
       }
     }
 
+    // toBe() or toEqual() are only invalid with null
+    if (matcherNode.name === "toBe" || matcherNode.name === "toEqual") {
+      if (!usesToBeOrToEqualWithNull(matcherNode, matcherArguments)) {
+        return;
+      }
+    }
+
     const query = queryNode.name || queryNode.property.name;
 
     if (queries.includes(query)) {