Installing dependencies.

node_modules/eslint-plugin-jest/lib/rules/prefer-equality-matcher.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+
+var _utils = require("@typescript-eslint/utils");
+
+var _utils2 = require("./utils");
+
+var _default = (0, _utils2.createRule)({
+  name: __filename,
+  meta: {
+    docs: {
+      category: 'Best Practices',
+      description: 'Suggest using the built-in equality matchers',
+      recommended: false,
+      suggestion: true
+    },
+    messages: {
+      useEqualityMatcher: 'Prefer using one of the equality matchers instead',
+      suggestEqualityMatcher: 'Use `{{ equalityMatcher }}`'
+    },
+    hasSuggestions: true,
+    type: 'suggestion',
+    schema: []
+  },
+  defaultOptions: [],
+
+  create(context) {
+    return {
+      CallExpression(node) {
+        const jestFnCall = (0, _utils2.parseJestFnCall)(node, context);
+
+        if ((jestFnCall === null || jestFnCall === void 0 ? void 0 : jestFnCall.type) !== 'expect' || jestFnCall.args.length === 0) {
+          return;
+        }
+
+        const {
+          parent: expect
+        } = jestFnCall.head.node;
+
+        if ((expect === null || expect === void 0 ? void 0 : expect.type) !== _utils.AST_NODE_TYPES.CallExpression) {
+          return;
+        }
+
+        const {
+          arguments: [comparison],
+          range: [, expectCallEnd]
+        } = expect;
+        const {
+          matcher
+        } = jestFnCall;
+        const matcherArg = (0, _utils2.getFirstMatcherArg)(jestFnCall);
+
+        if ((comparison === null || comparison === void 0 ? void 0 : comparison.type) !== _utils.AST_NODE_TYPES.BinaryExpression || comparison.operator !== '===' && comparison.operator !== '!==' || !_utils2.EqualityMatcher.hasOwnProperty((0, _utils2.getAccessorValue)(matcher)) || !(0, _utils2.isBooleanLiteral)(matcherArg)) {
+          return;
+        }
+
+        const matcherValue = matcherArg.value;
+        const [modifier] = jestFnCall.modifiers;
+        const hasNot = jestFnCall.modifiers.some(nod => (0, _utils2.getAccessorValue)(nod) === 'not'); // we need to negate the expectation if the current expected
+        // value is itself negated by the "not" modifier
+
+        const addNotModifier = (comparison.operator === '!==' ? !matcherValue : matcherValue) === hasNot;
+
+        const buildFixer = equalityMatcher => fixer => {
+          const sourceCode = context.getSourceCode(); // preserve the existing modifier if it's not a negation
+
+          let modifierText = modifier && (0, _utils2.getAccessorValue)(modifier) !== 'not' ? `.${(0, _utils2.getAccessorValue)(modifier)}` : '';
+
+          if (addNotModifier) {
+            modifierText += `.${_utils2.ModifierName.not}`;
+          }
+
+          return [// replace the comparison argument with the left-hand side of the comparison
+          fixer.replaceText(comparison, sourceCode.getText(comparison.left)), // replace the current matcher & modifier with the preferred matcher
+          fixer.replaceTextRange([expectCallEnd, matcher.parent.range[1]], `${modifierText}.${equalityMatcher}`), // replace the matcher argument with the right-hand side of the comparison
+          fixer.replaceText(matcherArg, sourceCode.getText(comparison.right))];
+        };
+
+        context.report({
+          messageId: 'useEqualityMatcher',
+          suggest: ['toBe', 'toEqual', 'toStrictEqual'].map(equalityMatcher => ({
+            messageId: 'suggestEqualityMatcher',
+            data: {
+              equalityMatcher
+            },
+            fix: buildFixer(equalityMatcher)
+          })),
+          node: matcher
+        });
+      }
+
+    };
+  }
+
+});
+
+exports.default = _default;