feature: @putout/plugin-putout: check-declare: add

Author: coderaiser

packages/plugin-eslint/lib/declare/eslint-flat.js

@@ -2,7 +2,7 @@
 
 module.exports = {
     matchToFlat: `import {matchToFlat} from '@putout/eslint-flat'`,
-    matchToFlatDir: `import {matchToFlat} from '@putout/eslint-flat'`,
+    matchToFlatDir: `import {matchToFlatDir} from '@putout/eslint-flat'`,
     mergeESLintConfigs: `import {mergeESLintConfigs} from '@putout/eslint-flat'`,
     createESLintConfig: `import {createESLintConfig} from '@putout/eslint-flat'`,
 };

packages/plugin-eslint/lib/declare/fixture/eslint-flat-fix.js

@@ -1,3 +1,4 @@
+import {matchToFlatDir} from '@putout/eslint-flat';
 import {matchToFlat} from '@putout/eslint-flat';
 import {mergeESLintConfigs} from '@putout/eslint-flat';
 import {createESLintConfig} from '@putout/eslint-flat';

packages/plugin-putout/README.md

@@ -37,6 +37,7 @@ npm i @putout/plugin-putout -D
 - ✅ [apply-parens](#apply-parens);
 - ✅ [apply-short-processors](#apply-short-processors);
 - ✅ [check-match](#check-match);
+- ✅ [check-declare](#check-declare);
 - ✅ [check-replace-code](#check-replace-code);
 - ✅ [convert-add-argument-to-add-args](#convert-add-argument-to-add-test-args);
 - ✅ [convert-babel-types](#convert-babel-types);
@@ -105,6 +106,7 @@ npm i @putout/plugin-putout -D
         "putout/apply-for-of-to-track-file": "on",
         "putout/apply-fixture-name-to-message": "on",
         "putout/check-match": "on",
+        "putout/check-declare": "on",
         "putout/check-replace-code": ["on", {
             "once": true
         }],
@@ -863,6 +865,23 @@ module.exports.match = () => ({
 });
 ```
 
+## check-declare
+
+Checks that [Declarator](https://github.com/coderaiser/putout/tree/master/packages/engine-runner#declarator) transform is possible.
+Checkout in 🐊[**Putout Editor**](https://putout.cloudcmd.io/#/gist/9fccb187bb8933afff0dc0db57b3cea8/25cb812978fadb4efb5f0cb44058a61f70f8b78e):
+
+### ❌ Example of incorrect code
+
+```js
+module.exports.declare = () => ({
+    isNumber: 'const isNumber = () => {}',
+    isString: 'const isNumber = () => {}',
+});
+```
+
+☝️ *There is no `fix` for this rule, it used internally to be more confident about `test coverage`, because of declaration form, transforms cannon be checked by `nyc` and `c8`, and uncovered lines can find unfixable false positives when running on code.
+This is additional tests, if you forget to test some case (from a big list of rules that is supported) it will be checked with this `rule` and make transforms more stable.*
+
 ## check-replace-code
 
 Checks that [Replacer](https://github.com/coderaiser/putout/tree/master/packages/engine-runner#replacer) transform is possible.

packages/plugin-putout/lib/check-declare/fixture/check-declare.js

@@ -0,0 +1,9 @@
+module.exports.declare = () => ({
+    isNumber: 'const isNumber = () => {}',
+    isString: 'const isNumber = () => {}',
+});
+
+export const declare = () => ({
+    isHello: 'const isHello = () => {}',
+    isWorld: 'const isHello = () => {}',
+});

packages/plugin-putout/lib/check-declare/fixture/commonjs-template.js

@@ -0,0 +1,4 @@
+module.exports = {
+    isNumber: `const isNumber = () => {}`,
+    isString: `const isNumber = () => {}`,
+};

packages/plugin-putout/lib/check-declare/fixture/commonjs.js

@@ -0,0 +1,4 @@
+module.exports = {
+    isNumber: 'const isNumber = () => {}',
+    isString: 'const isNumber = () => {}',
+};

packages/plugin-putout/lib/check-declare/fixture/couple-quasis.js

@@ -0,0 +1,3 @@
+module.exports = {
+    getRule: `const getRule = ${getRule.toString()};`
+};

packages/plugin-putout/lib/check-declare/fixture/not-declaration.js

@@ -0,0 +1,3 @@
+module.exports = {
+    lint: 'putout .',
+};

packages/plugin-putout/lib/check-declare/index.js

@@ -0,0 +1,62 @@
+'use strict';
+
+const tryCatch = require('try-catch');
+const putout = require('putout');
+
+const {types, operator} = putout;
+
+const noop = () => {};
+const {getTemplateValues} = operator;
+
+const DECLARE_ESM = 'export const declare = () => __object';
+const DECLARE_COMMONJS = 'module.exports.declare = () => __object';
+const COMMONJS = 'module.exports = __object';
+
+const {
+    isTemplateLiteral,
+    isStringLiteral,
+} = types;
+
+module.exports.report = ({message}) => message;
+
+module.exports.fix = noop;
+module.exports.traverse = ({push}) => ({
+    [DECLARE_ESM]: createCheck(push, DECLARE_ESM),
+    [DECLARE_COMMONJS]: createCheck(push, DECLARE_COMMONJS),
+    [COMMONJS]: createCheck(push, COMMONJS),
+});
+
+const createCheck = (push, template) => (path) => {
+    const {__object} = getTemplateValues(path, template);
+    
+    const lines = [];
+    
+    for (const {value} of __object.properties) {
+        let current = '';
+        
+        if (isStringLiteral(value)) {
+            current = value.value;
+        } else if (isTemplateLiteral(value)) {
+            if (value.quasis.length > 1)
+                continue;
+            
+            current = value.quasis[0].value.cooked;
+        }
+        
+        if (/^(const|import)/.test(current))
+            lines.push(current);
+    }
+    
+    const source = lines.join(';\n');
+    const [error] = tryCatch(putout.parse, source);
+    
+    if (!error)
+        return;
+    
+    const {message} = error;
+    
+    push({
+        path,
+        message,
+    });
+};

packages/plugin-putout/lib/check-declare/index.spec.js

@@ -0,0 +1,43 @@
+'use strict';
+
+const {createTest} = require('@putout/test');
+const plugin = require('.');
+
+const test = createTest(__dirname, {
+    plugins: [
+        ['check-declare', plugin],
+    ],
+});
+
+test('putout: check-declare: report', (t) => {
+    t.report('check-declare', [
+        `Identifier 'isNumber' has already been declared. (2:6)`,
+        `Identifier 'isHello' has already been declared. (2:6)`,
+    ]);
+    t.end();
+});
+
+test('putout: check-declare: report: commonjs', (t) => {
+    t.report('commonjs', `Identifier 'isNumber' has already been declared. (2:6)`);
+    t.end();
+});
+
+test('putout: check-declare: report: commonjs-template', (t) => {
+    t.report('commonjs-template', `Identifier 'isNumber' has already been declared. (2:6)`);
+    t.end();
+});
+
+test('putout: check-declare: no transform', (t) => {
+    t.noTransform('check-declare');
+    t.end();
+});
+
+test('putout: check-declare: no report: not-declaration', (t) => {
+    t.noReport('not-declaration');
+    t.end();
+});
+
+test('putout: check-declare: no report: couple-quasis', (t) => {
+    t.noReport('couple-quasis');
+    t.end();
+});