Merge pull request #96 from ShridharGoel/boolean-update

Add custom config to use double negation instead of Boolean

Author: aldo-expensify

eslint-plugin-expensify/CONST.js

@@ -28,6 +28,7 @@ module.exports = {
         MUST_USE_VARIABLE_FOR_ASSIGNMENT: '{{key}} must be assigned as a variable instead of direct assignment.',
         NO_DEFAULT_PROPS: 'defaultProps should not be used in function components. Use default Arguments instead.',
         USE_PERIODS_ERROR_MESSAGES: 'Use periods at the end of error messages.',
+        USE_DOUBLE_NEGATION_INSTEAD_OF_BOOLEAN: 'Use !! instead of Boolean().',
         NO_ACC_SPREAD_IN_REDUCE: 'Avoid a use of spread (`...`) operator on accumulators in reduce callback. Mutate them directly instead.',
     },
 };

eslint-plugin-expensify/tests/use-double-negation-instead-of-boolean.test.js

@@ -0,0 +1,77 @@
+const RuleTester = require('eslint').RuleTester;
+const rule = require('../use-double-negation-instead-of-boolean');
+const message = require('../CONST').MESSAGE.USE_DOUBLE_NEGATION_INSTEAD_OF_BOOLEAN;
+
+const ruleTester = new RuleTester({
+    parserOptions: {
+        ecmaVersion: 6,
+        sourceType: 'module',
+    },
+});
+
+ruleTester.run('use-double-negation-instead-of-Boolean()', rule, {
+    valid: [
+        {
+            code: '!!test',
+        },
+        {
+            code: '!!(test1 || test2)',
+        },
+        {
+            code: '!!(test1 && test2)',
+        },
+        {
+            code: '!!(test1 && (test2 || test3))',
+        },
+        {
+            code: '!!(test1 || test2 && test3)',
+        },
+        {
+            code: '!!test ? "" : "example"',
+        },
+    ],
+    invalid: [
+        {
+            code: 'Boolean(test)',
+            output: '!!test',
+            errors: [{
+                message,
+            }],
+        },
+        {
+            code: 'Boolean(test1 || test2)',
+            output: '!!(test1 || test2)',
+            errors: [{
+                message,
+            }],
+        },
+        {
+            code: 'Boolean(test1 && test2)',
+            output: '!!(test1 && test2)',
+            errors: [{
+                message,
+            }],
+        },
+        {
+            code: 'Boolean(test1 && (test2 || test3))',
+            output: '!!(test1 && (test2 || test3))',
+            errors: [{
+                message,
+            }],
+        },
+        {
+            code: 'Boolean(test1 || test2 && test3)',
+            output: '!!(test1 || test2 && test3)',
+            errors: [{
+                message,
+            }],
+        },
+        {
+            code: 'Boolean(test) ? "" : "example"',
+            output: '!!test ? "" : "example"',
+            errors: [{
+                message,
+            }],
+        },
+    ],
+});

eslint-plugin-expensify/use-double-negation-instead-of-boolean.js

@@ -0,0 +1,31 @@
+const message = require('./CONST').MESSAGE.USE_DOUBLE_NEGATION_INSTEAD_OF_BOOLEAN;
+
+module.exports = {
+    meta: {
+        fixable: 'code',
+    },
+    create(context) {
+        return {
+            CallExpression(node) {
+                if (node.callee.type === 'Identifier' && node.callee.name === 'Boolean' && node.arguments.length === 1) {
+                    const argument = node.arguments[0];
+                    const sourceCode = context.getSourceCode();
+                    const argumentText = sourceCode.getText(argument);
+                    let fixedText = `!!${argumentText}`;
+
+                    if (argument.type === 'LogicalExpression' || argument.type === 'BinaryExpression') {
+                        fixedText = `!!(${argumentText})`;
+                    }
+
+                    context.report({
+                        node,
+                        message,
+                        fix(fixer) {
+                            return fixer.replaceText(node, fixedText);
+                        },
+                    });
+                }
+            },
+        };
+    },
+};

rules/expensify.js

@@ -15,6 +15,7 @@ module.exports = {
         'rulesdir/no-call-actions-from-actions': 'error',
         'rulesdir/no-api-side-effects-method': 'error',
         'rulesdir/prefer-localization': 'error',
+        'rulesdir/use-double-negation-instead-of-boolean': 'error',
         'rulesdir/no-acc-spread-in-reduce': 'error',
         'no-restricted-imports': ['error', {
             paths: [{