feature(eslint-plugin-putout) single-property.js (https://gist.github…

….com/coderaiser/e40f007509edd5528c21a7eab8fad321)

packages/eslint-plugin-putout/rules/single-property.js

@@ -0,0 +1,53 @@
+'use strict';
+
+module.exports = {
+    meta: {
+        type: 'layout',
+        docs: {
+            description: 'Keep curly braces on one line when you have one destructuring property',
+            category: 'destructuring',
+            recommended: true,
+        },
+        fixable: 'whitespace',
+    },
+
+    create(context) {
+        return {
+            'VariableDeclarator[id.type="ObjectPattern"][id.properties.length=1]': (node) => {
+                const {id} = node;
+
+                const text = context
+                    .getSourceCode()
+                    .getText(node.parent);
+
+                if (!/(const|let|var) \{\n/.test(text))
+                    return;
+
+                const assignRegExp = /\{\n?.*=.*\n?.*}/;
+
+                if (assignRegExp.test(text))
+                    return;
+
+                context.report({
+                    node,
+                    message: 'Keep curly braces on one line when you have one destructuring property',
+
+                    fix(fixer) {
+                        const [property] = id.properties;
+                        const {key, value} = property;
+
+                        if (key.name === value.name)
+                            return [
+                                fixer.replaceText(id, `{${key.name}}`),
+                            ];
+
+                        return [
+                            fixer.replaceText(id, `{${key.name}: ${value.name}}`),
+                        ];
+                    },
+                });
+            },
+        };
+    },
+};
+

packages/eslint-plugin-putout/rules/single-property.md

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+# keep curly bracesin in one line when property is single (single-property-destructuring)
+
+When `putout` removes unused variables declared as destructured properties, it keeps one property to take 3 lines, instead of 1.
+
+## Rule Details
+
+This rule aims to shorten destricturing of one property.
+
+Examples of **incorrect** code for this rule:
+
+```js
+const {
+    username
+} = user;
+```
+
+Examples of **correct** code for this rule:
+
+```js
+const {username} = user;
+```
+

packages/eslint-plugin-putout/rules/single-property.spec.js

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+'use strict';
+
+const rule = require('./single-property-destructuring');
+const {RuleTester} = require('eslint');
+
+const ruleTester = new RuleTester({
+    parserOptions: {
+        ecmaVersion: 2019,
+    },
+});
+
+ruleTester.run('single-property-destructuring', rule, {
+    valid: [
+        `const {hello} = world;`,
+        `const {hello} = get({});`,
+        `const {
+            hello = true
+        } = world;`,
+    ],
+
+    invalid: [{
+        code: `const {\n    hello\n} = world`,
+        output: 'const {hello} = world',
+        errors: [{
+            message: 'Keep curly braces on one line when you have one destructuring property',
+            type: 'VariableDeclarator',
+        }],
+    }, {
+        code: `const {\n    hello: h\n} = world`,
+        output: 'const {hello: h} = world',
+        errors: [{
+            message: 'Keep curly braces on one line when you have one destructuring property',
+            type: 'VariableDeclarator',
+        }],
+    }],
+});
+