order: enforce imports being before require

Author: jfmengels

docs/rules/order.md

@@ -22,7 +22,9 @@ import baz from './bar/baz';
 import main from './';
 ```
 
-Unassigned imports are not accounted for, as the order they are imported in may be important.
+Unassigned imports are ignored, as the order they are imported in may be important.
+
+Statements using the ES6 `import` syntax must appear before any `require()` statements.
 
 
 ## Fail
@@ -35,6 +37,11 @@ import path from 'path'; // `path` import should occur before import of `lodash`
 
 var _ = require('lodash');
 var path = require('path'); // `path` import should occur before import of `lodash`
+
+// -----
+
+var path = require('path');
+import foo from './foo'; // `import` statements must be before `require` statement
 ```
 
 
@@ -54,6 +61,12 @@ var _ = require('lodash');
 // Allowed as ̀`babel-register` is not assigned.
 require('babel-register');
 var path = require('path');
+
+// -----
+
+// Allowed as `import` must be before `require`
+import foo from './foo';
+var path = require('path');
 ```
 
 ## Options

src/rules/order.js

@@ -59,14 +59,15 @@ function makeReport(context, imported) {
 
 // DETECTING
 
-function computeRank(context, ranks, name) {
-  return ranks[importType(name, context)]
+function computeRank(context, ranks, name, type) {
+  return ranks[importType(name, context)] +
+    (type === 'import' ? 0 : 100)
 }
 
-function registerNode(context, node, name, ranks, imported) {
-  const rank = computeRank(context, ranks, name)
+function registerNode(context, node, name, type, ranks, imported) {
+  const rank = computeRank(context, ranks, name, type)
   if (rank !== -1) {
-    imported.push({name: name, rank: rank, node: node})
+    imported.push({name, rank, node})
   }
 }
 
@@ -136,15 +137,15 @@ module.exports = function importOrderRule (context) {
     ImportDeclaration: function handleImports(node) {
       if (node.specifiers.length) { // Ignoring unassigned imports
         const name = node.source.value
-        registerNode(context, node, name, ranks, imported)
+        registerNode(context, node, name, 'import', ranks, imported)
       }
     },
     CallExpression: function handleRequires(node) {
       if (level !== 0 || !isStaticRequire(node) || !isInVariableDeclarator(node.parent)) {
         return
       }
       const name = node.arguments[0].value
-      registerNode(context, node, name, ranks, imported)
+      registerNode(context, node, name, 'require', ranks, imported)
     },
     'Program:exit': function reportAndReset() {
       makeReport(context, imported)

tests/src/rules/order.js

@@ -29,17 +29,6 @@ ruleTester.run('order', rule, {
         import sibling, {foo3} from './foo';
         import index from './';`,
       }),
-    // Default order using both require and import
-    test({
-      code: `
-        var fs = require('fs');
-        import async, {foo1} from 'async';
-        var relParent1 = require('../foo');
-        import relParent2, {foo2} from '../foo/bar';
-        var relParent3 = require('../');
-        import sibling, {foo3} from './foo';
-        var index = require('./');`,
-      }),
     // Multiple module of the same rank next to each other
     test({
       code: `
@@ -159,6 +148,18 @@ ruleTester.run('order', rule, {
         // missing 'builtin'
       ]}],
     }),
+    // Mixing require and import should have import up top
+    test({
+      code: `
+        import async, {foo1} from 'async';
+        import relParent2, {foo2} from '../foo/bar';
+        import sibling, {foo3} from './foo';
+        var fs = require('fs');
+        var relParent1 = require('../foo');
+        var relParent3 = require('../');
+        var index = require('./');
+      `,
+    }),
   ],
   invalid: [
     // builtin before external module (require)
@@ -385,5 +386,32 @@ ruleTester.run('order', rule, {
         message: 'Incorrect configuration of the rule: `parent` is duplicated',
       }],
     }),
+    // Mixing require and import should have import up top
+    test({
+      code: `
+        import async, {foo1} from 'async';
+        import relParent2, {foo2} from '../foo/bar';
+        var fs = require('fs');
+        var relParent1 = require('../foo');
+        var relParent3 = require('../');
+        import sibling, {foo3} from './foo';
+        var index = require('./');
+      `,
+      errors: [{
+        ruleId: 'order',
+        message: '`./foo` import should occur before import of `fs`',
+      }],
+    }),
+    test({
+      code: `
+        var fs = require('fs');
+        import async, {foo1} from 'async';
+        import relParent2, {foo2} from '../foo/bar';
+      `,
+      errors: [{
+        ruleId: 'order',
+        message: '`fs` import should occur after import of `../foo/bar`',
+      }],
+    }),
   ],
 })