chore: Add shared equality matchers

Author: mskelton

src/rules/prefer-comparison-matcher.ts

@@ -1,6 +1,7 @@
 import { Rule } from 'eslint';
 import * as ESTree from 'estree';
 import {
+  equalityMatchers,
   getParent,
   getRawValue,
   getStringValue,
@@ -9,8 +10,6 @@ import {
 } from '../utils/ast';
 import { parseExpectCall } from '../utils/parseExpectCall';
 
-const equalityMatchers = new Set(['toBe', 'toEqual', 'toStrictEqual']);
-
 const isString = (node: ESTree.Node) => {
   return isStringLiteral(node) || node.type === 'TemplateLiteral';
 };

src/rules/prefer-to-be.ts

@@ -1,6 +1,6 @@
 import { Rule } from 'eslint';
 import ESTree from 'estree';
-import { getStringValue, isIdentifier } from '../utils/ast';
+import { equalityMatchers, getStringValue, isIdentifier } from '../utils/ast';
 import { replaceAccessorFixer } from '../utils/fixer';
 import { ParsedExpectCall, parseExpectCall } from '../utils/parseExpectCall';
 
@@ -69,10 +69,8 @@ export default {
           );
         }
 
-        const argumentMatchers = ['toBe', 'toEqual', 'toStrictEqual'];
         const firstArg = expectCall.args[0];
-
-        if (!argumentMatchers.includes(expectCall.matcherName) || !firstArg) {
+        if (!equalityMatchers.has(expectCall.matcherName) || !firstArg) {
           return;
         }
 

src/rules/prefer-to-contain.ts

@@ -1,15 +1,14 @@
 import { Rule } from 'eslint';
 import ESTree from 'estree';
 import {
+  equalityMatchers,
   getStringValue,
   isBooleanLiteral,
   isPropertyAccessor,
 } from '../utils/ast';
 import { parseExpectCall } from '../utils/parseExpectCall';
 import { KnownCallExpression } from '../utils/types';
 
-const matchers = new Set(['toBe', 'toEqual', 'toStrictEqual']);
-
 type FixableIncludesCallExpression = KnownCallExpression;
 
 const isFixableIncludesCallExpression = (
@@ -35,7 +34,7 @@ export default {
         if (
           !includesCall ||
           matcherArg.type === 'SpreadElement' ||
-          !matchers.has(matcherName) ||
+          !equalityMatchers.has(matcherName) ||
           !isBooleanLiteral(matcherArg) ||
           !isFixableIncludesCallExpression(includesCall)
         ) {

src/rules/prefer-to-have-count.ts

@@ -1,16 +1,14 @@
 import { Rule } from 'eslint';
-import { isPropertyAccessor } from '../utils/ast';
+import { equalityMatchers, isPropertyAccessor } from '../utils/ast';
 import { replaceAccessorFixer } from '../utils/fixer';
 import { parseExpectCall } from '../utils/parseExpectCall';
 
-const matchers = new Set(['toBe', 'toEqual', 'toStrictEqual']);
-
 export default {
   create(context) {
     return {
       CallExpression(node) {
         const expectCall = parseExpectCall(context, node);
-        if (!expectCall || !matchers.has(expectCall.matcherName)) {
+        if (!expectCall || !equalityMatchers.has(expectCall.matcherName)) {
           return;
         }
 

src/rules/prefer-to-have-length.ts

@@ -1,16 +1,14 @@
 import { Rule } from 'eslint';
-import { isPropertyAccessor } from '../utils/ast';
+import { equalityMatchers, isPropertyAccessor } from '../utils/ast';
 import { replaceAccessorFixer } from '../utils/fixer';
 import { parseExpectCall } from '../utils/parseExpectCall';
 
-const lengthMatchers = new Set(['toBe', 'toEqual', 'toStrictEqual']);
-
 export default {
   create(context) {
     return {
       CallExpression(node) {
         const expectCall = parseExpectCall(context, node);
-        if (!expectCall || !lengthMatchers.has(expectCall.matcherName)) {
+        if (!expectCall || !equalityMatchers.has(expectCall.matcherName)) {
           return;
         }
 

src/utils/ast.ts

@@ -229,3 +229,5 @@ export function isFunction(node: ESTree.Node): node is FunctionExpression {
     node.type === 'FunctionExpression'
   );
 }
+
+export const equalityMatchers = new Set(['toBe', 'toEqual', 'toStrictEqual']);

test/spec/prefer-comparison-matcher.spec.ts

@@ -1,5 +1,6 @@
 import { RuleTester } from 'eslint';
 import rule from '../../src/rules/prefer-comparison-matcher';
+import { equalityMatchers } from '../../src/utils/ast';
 import { runRuleTester } from '../utils/rule-tester';
 
 const generateInvalidCases = (
@@ -248,9 +249,7 @@ const testComparisonOperator = (
   preferredMatcherWhenNegated: string,
 ) => {
   runRuleTester(`prefer-comparision-matcher: ${operator}`, rule, {
-    invalid: ['toBe', 'toEqual', 'toStrictEqual'].reduce<
-      RuleTester.InvalidTestCase[]
-    >(
+    invalid: [...equalityMatchers.keys()].reduce<RuleTester.InvalidTestCase[]>(
       (cases, equalityMatcher) => [
         ...cases,
         ...generateInvalidCases(