Fix: require-meta-schema: Fix false positive (#111)

* Add failed test

* Fix test

* Style

* Fix

* One more test

* Unpin version

Author: fisker

lib/rules/require-meta-schema.js

@@ -1,5 +1,6 @@
 'use strict';
 
+const { findVariable } = require('eslint-utils');
 const utils = require('../utils');
 
 // ------------------------------------------------------------------------------
@@ -34,7 +35,8 @@ module.exports = {
 
   create (context) {
     const sourceCode = context.getSourceCode();
-    const info = utils.getRuleInfo(sourceCode.ast, sourceCode.scopeManager);
+    const { ast, scopeManager } = sourceCode;
+    const info = utils.getRuleInfo(ast, scopeManager);
 
     return {
       Program () {
@@ -56,8 +58,33 @@ module.exports = {
               return utils.insertProperty(fixer, metaNode, 'schema: []', sourceCode);
             },
           });
-        } else if (!['ArrayExpression', 'ObjectExpression'].includes(schemaNode.value.type)) {
-          context.report({ node: schemaNode.value, messageId: 'wrongType' });
+          return;
+        }
+
+        let { value } = schemaNode;
+        if (value.type === 'Identifier') {
+          const variable = findVariable(
+            scopeManager.acquire(value) || scopeManager.globalScope,
+            value
+          );
+
+          // If we can't find the declarator, we have to assume it's in correct type
+          if (
+            !variable ||
+            !variable.defs ||
+            !variable.defs[0] ||
+            !variable.defs[0].node ||
+            variable.defs[0].node.type !== 'VariableDeclarator' ||
+            !variable.defs[0].node.init
+          ) {
+            return;
+          }
+
+          value = variable.defs[0].node.init;
+        }
+
+        if (!['ArrayExpression', 'ObjectExpression'].includes(value.type)) {
+          context.report({ node: value, messageId: 'wrongType' });
         }
       },
     };

package.json

@@ -27,7 +27,9 @@
     "url": "https://github.com/not-an-aardvark/eslint-plugin-eslint-plugin/issues"
   },
   "homepage": "https://github.com/not-an-aardvark/eslint-plugin-eslint-plugin#readme",
-  "dependencies": {},
+  "dependencies": {
+    "eslint-utils": "^2.1.0"
+  },
   "devDependencies": {
     "@not-an-aardvark/node-release-script": "^0.1.0",
     "chai": "^4.1.0",

tests/lib/rules/require-meta-schema.js

@@ -32,6 +32,36 @@ ruleTester.run('require-meta-schema', rule, {
         create(context) {}
       };
     `,
+    `
+      const schema = [];
+      module.exports = {
+        meta: { schema },
+        create(context) {}
+      };
+    `,
+    `
+      const foo = {};
+      module.exports = {
+        meta: { schema: foo },
+        create(context) {}
+      };
+    `,
+    `
+      let schema;
+      schema = foo ? [] : {};
+      module.exports = {
+        meta: { schema },
+        create(context) {}
+      };
+    `,
+    `
+      const schema = [],
+            created = (context) => {};
+      module.exports = {
+        meta: { schema },
+        create
+      };
+    `,
   ],
 
   invalid: [
@@ -78,5 +108,16 @@ schema: [] },
       output: null,
       errors: [{ messageId: 'wrongType', type: 'Literal' }],
     },
+    {
+      code: `
+        const schema = null;
+        module.exports = {
+          meta: { schema },
+          create(context) {}
+        };
+      `,
+      output: null,
+      errors: [{ messageId: 'wrongType', type: 'Literal' }],
+    },
   ],
 });