feat: added 3 rules

Author: Ben Monro

.eslintignore

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+coverage/

.eslintrc.json

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+{
+    "parserOptions": {
+        "ecmaVersion": 2018
+    },
+    "env": {
+        "commonjs": true,
+        "es6": true,
+        "node": true
+        // "jest/globals": true
+    },
+    "plugins": [
+        "eslint-plugin",
+        "prettier"
+    ],
+    "extends": [
+        "plugin:eslint-plugin/recommended"
+    ],
+    "rules": {
+        "prettier/prettier": "error",
+        "no-var": "error"
+    }
+}

.gitignore

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+node_modules
+coverage
+yarn.lock
+package-lock.json

.prettierrc.json

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+{
+  "trailingComma": "es5",
+  "singleQuote": true
+}

README.md

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+# eslint-plugin-jest-dom
+
+lint rules for use with jest-dom
+
+## Installation
+
+You'll first need to install [ESLint](http://eslint.org):
+
+```
+$ npm i eslint --save-dev
+```
+
+Next, install `eslint-plugin-jest-dom`:
+
+```
+$ npm install eslint-plugin-jest-dom --save-dev
+```
+
+**Note:** If you installed ESLint globally (using the `-g` flag) then you must also install `eslint-plugin-jest-dom` globally.
+
+## Usage
+
+Add `jest-dom` to the plugins section of your `.eslintrc` configuration file. You can omit the `eslint-plugin-` prefix:
+
+```json
+{
+    "plugins": [
+        "jest-dom"
+    ]
+}
+```
+
+
+Then configure the rules you want to use under the rules section.
+
+```json
+{
+    "rules": {
+        "jest-dom/prefer-checked": "error",
+        "jest-dom/prefer-enabled-disabled": "error",
+        "jest-dom/prefer-required": "error"
+    }
+}
+```
+
+## Supported Rules
+
+✔️ indicates that a rule is recommended for all users.
+
+🛠 indicates that a rule is fixable.
+
+<!-- __BEGIN AUTOGENERATED TABLE__ -->
+Name | ✔️ | 🛠 | Description
+----- | ----- | ----- | -----
+[prefer-checked](https://github.com/testing-library/eslint-plugin-jest-dom/blob/master/docs/rules/prefer-checked.md) | ✔️ | 🛠 | prefer toBeChecked over checking attributes
+[prefer-enabled-disabled](https://github.com/testing-library/eslint-plugin-jest-dom/blob/master/docs/rules/prefer-enabled-disabled.md) | ✔️ | 🛠 | prefer toBeDisabled or toBeEnabled over checking attributes
+[prefer-required](https://github.com/testing-library/eslint-plugin-jest-dom/blob/master/docs/rules/prefer-required.md) | ✔️ | 🛠 | prefer toBeRequired over checking properties
+<!-- __END AUTOGENERATED TABLE__ -->
+
+
+
+
+

build/generate-readme-table.js

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+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+const rules = require('..').rules;
+
+const README_LOCATION = path.resolve(__dirname, '..', 'README.md');
+const BEGIN_TABLE_MARKER = '<!-- __BEGIN AUTOGENERATED TABLE__ -->\n';
+const END_TABLE_MARKER = '\n<!-- __END AUTOGENERATED TABLE__ -->';
+
+const expectedTableLines = Object.keys(rules)
+  .sort()
+  .reduce(
+    (lines, ruleId) => {
+      const rule = rules[ruleId];
+
+      lines.push(
+        [
+          `[${ruleId}](https://github.com/testing-library/eslint-plugin-jest-dom/blob/master/docs/rules/${ruleId}.md)`,
+          rule.meta.docs.recommended ? '✔️' : '',
+          rule.meta.fixable ? '🛠' : '',
+          rule.meta.docs.description,
+        ].join(' | ')
+      );
+
+      return lines;
+    },
+    ['Name | ✔️ | 🛠 | Description', '----- | ----- | ----- | -----']
+  )
+  .join('\n');
+
+const readmeContents = fs.readFileSync(README_LOCATION, 'utf8');
+
+if (!readmeContents.includes(BEGIN_TABLE_MARKER)) {
+  throw new Error(
+    `Could not find '${BEGIN_TABLE_MARKER}' marker in README.md.`
+  );
+}
+
+if (!readmeContents.includes(END_TABLE_MARKER)) {
+  throw new Error(`Could not find '${END_TABLE_MARKER}' marker in README.md.`);
+}
+
+const linesStartIndex =
+  readmeContents.indexOf(BEGIN_TABLE_MARKER) + BEGIN_TABLE_MARKER.length;
+const linesEndIndex = readmeContents.indexOf(END_TABLE_MARKER);
+
+const updatedReadmeContents =
+  readmeContents.slice(0, linesStartIndex) +
+  expectedTableLines +
+  readmeContents.slice(linesEndIndex);
+
+if (module.parent) {
+  module.exports = updatedReadmeContents;
+} else {
+  fs.writeFileSync(README_LOCATION, updatedReadmeContents);
+}

docs/rules/prefer-enabled-disabled.md

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+# prefer toBeDisabled() or toBeEnabled() over toHaveProperty('disabled', true|false) (prefer-enabled-disabled)
+
+## Rule Details
+
+This rule aims to prevent false positives and improve readability and should only be used with the `@testing-library/jest-dom` package. See below for examples of those potential issues and why this rule is recommended. The rule is autofixable and will replace any instances of `.toHaveProperty()` or `.toHaveAttribute()` with `.toBeEnabled()` or `toBeDisabled()` as appropriate.
+
+In addition, to avoid double negatives and confusing syntax, `expect(element).not.toBeDisabled()` is also reported and auto-fixed to `expect(element).toBeEnabled()` and vice versa.
+
+### False positives
+
+Consider these 2 snippets:
+
+```js
+const { getByRole } = render(<input type="checkbox" disabled />);
+const element = getByRole('checkbox');
+expect(element).toHaveProperty('disabled'); // passes
+
+const { getByRole } = render(<input type="checkbox" />);
+const element = getByRole('checkbox');
+expect(element).toHaveProperty('disabled'); // also passes 😱
+```
+
+### Readability
+
+Consider the following snippets:
+
+```js
+const { getByRole } = render(<input type="checkbox" />);
+const element = getByRole('checkbox');
+
+expect(element).toHaveAttribute('disabled', false); // fails
+expect(element).toHaveAttribute('disabled', ''); // fails
+expect(element).not.toHaveAttribute('disabled', ''); // passes
+
+expect(element).not.toHaveAttribute('disabled', true); // passes.
+expect(element).not.toHaveAttribute('disabled', false); // also passes.
+```
+
+As you can see, using `toHaveAttribute` in this case is confusing, unintuitive and can even lead to false positive tests.
+
+Examples of **incorrect** code for this rule:
+
+```js
+expect(element).toHaveProperty('disabled', true);
+expect(element).toHaveAttribute('disabled', false);
+
+expect(element).toHaveAttribute('disabled');
+expect(element).not.toHaveProperty('disabled');
+
+expect(element).not.toBeDisabled();
+expect(element).not.toBeEnabled();
+```
+
+Examples of **correct** code for this rule:
+
+```js
+expect(element).toBeEnabled();
+
+expect(element).toBeDisabled();
+
+expect(element).toHaveProperty('checked', true);
+
+expect(element).toHaveAttribute('checked');
+```
+
+## When Not To Use It
+
+Don't use this rule if you:
+
+- don't use `jest-dom`
+- want to allow `.toHaveProperty('disabled', true|false);`
+
+## Further reading
+
+- [toBeDisabled](https://github.com/testing-library/jest-dom#tobedisabled)
+- [toBeEnabled](https://github.com/testing-library/jest-dom#tobeenabled)

jest.config.js

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+module.exports = {
+  testMatch: ['**/tests/**/*.js'],
+  collectCoverage: true,
+  coverageThreshold: {
+    global: {
+      branches: 96.55,
+      functions: 100,
+      lines: 98.97,
+      statements: 0,
+    },
+  },
+  testPathIgnorePatterns: ['<rootDir>/tests/fixtures/'],
+  collectCoverageFrom: ['lib/**/*.js', '!**/node_modules/**'],
+};

lib/createBannedAttributeRule.js

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+module.exports = ({ preferred, negatedPreferred, attributes }) => context => {
+  function getCorrectFunctionFor(node, negated = false) {
+    return (node.arguments.length === 1 ||
+      node.arguments[1].value === true ||
+      node.arguments[1].value === '') &&
+      !negated
+      ? preferred
+      : negatedPreferred;
+  }
+
+  const isBannedArg = node =>
+    attributes.some(attr => attr === node.arguments[0].value);
+
+  return {
+    [`CallExpression[callee.property.name=/${preferred}|${negatedPreferred}/][callee.object.property.name='not'][callee.object.object.callee.name='expect']`](
+      node
+    ) {
+      if (negatedPreferred.startsWith('toBe')) {
+        const incorrectFunction = node.callee.property.name;
+
+        const correctFunction =
+          incorrectFunction === preferred ? negatedPreferred : preferred;
+        context.report({
+          message: `Use ${correctFunction}() instead of not.${incorrectFunction}()`,
+          node,
+          fix(fixer) {
+            return fixer.replaceTextRange(
+              [node.callee.object.property.start, node.end],
+              `${correctFunction}()`
+            );
+          },
+        });
+      }
+    },
+    "CallExpression[callee.property.name=/toHaveProperty|toHaveAttribute/][callee.object.property.name='not'][callee.object.object.callee.name='expect']"(
+      node
+    ) {
+      const arg = node.arguments[0].value;
+      if (isBannedArg(node)) {
+        const correctFunction = getCorrectFunctionFor(node, true);
+
+        const incorrectFunction = node.callee.property.name;
+        context.report({
+          message: `Use ${correctFunction}() instead of not.${incorrectFunction}('${arg}')`,
+          node,
+          fix(fixer) {
+            return fixer.replaceTextRange(
+              [node.callee.object.property.start, node.end],
+              `${correctFunction}()`
+            );
+          },
+        });
+      }
+    },
+    "CallExpression[callee.object.callee.name='expect'][callee.property.name=/toHaveProperty|toHaveAttribute/]"(
+      node
+    ) {
+      if (isBannedArg(node)) {
+        const correctFunction = getCorrectFunctionFor(node);
+
+        const incorrectFunction = node.callee.property.name;
+
+        const message = `Use ${correctFunction}() instead of ${incorrectFunction}(${node.arguments
+          .map(({ raw }) => raw)
+          .join(', ')})`;
+        context.report({
+          node: node.callee.property,
+          message,
+          fix(fixer) {
+            return [
+              fixer.replaceTextRange(
+                [node.callee.property.start, node.end],
+                `${correctFunction}()`
+              ),
+            ];
+          },
+        });
+      }
+    },
+  };
+};

lib/index.js

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+/**
+ * @fileoverview lint rules for use with jest-dom
+ * @author Ben Monro
+ */
+'use strict';
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+let requireIndex = require('requireindex');
+
+//------------------------------------------------------------------------------
+// Plugin Definition
+//------------------------------------------------------------------------------
+
+// import all rules in lib/rules
+module.exports.rules = requireIndex(__dirname + '/rules');

lib/rules/prefer-checked.js

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+/**
+ * @fileoverview prefer toBeDisabled or toBeEnabled over attribute checks
+ * @author Ben Monro
+ */
+'use strict';
+
+const createBannedAttributeRule = require('../createBannedAttributeRule');
+
+module.exports = {
+  meta: {
+    docs: {
+      description:
+        'prefer toBeChecked over checking attributes',
+      category: 'jest-dom',
+      recommended: true,
+      url: 'prefer-checked',
+    },
+    fixable: 'code',
+  },
+
+  create: createBannedAttributeRule({
+    preferred: 'toBeChecked',
+    negatedPreferred: 'not.toBeChecked',
+    attributes: ['checked', 'aria-checked'],
+  }),
+};