Convert require statements to imports

test/fixtures/amd_with_require.after.js

@@ -0,0 +1,14 @@
+import a from 'a';
+import b from 'b';
+import c from 'c';
+import g from 'g';
+var d, e, f;
+
+// let's define some things
+var myModule = {
+    doStuffWithThings(val) {
+        return a.morgify(val);
+    },
+};
+
+export default myModule;

test/fixtures/amd_with_require.before.js

@@ -0,0 +1,15 @@
+define(function(require) {
+    var a = require('a');
+    var b = require('b');
+    var c = require('c');
+    var d, e, f, g = require('g');
+
+    // let's define some things
+    var myModule = {
+        doStuffWithThings(val) {
+            return a.morgify(val);
+        },
+    };
+
+    return myModule;
+});

test/transforms/amd.js

@@ -24,4 +24,11 @@ describe('AMD transform', function() {
     var result = amdTransform({ source: src }, { jscodeshift: jscodeshift });
     assert.equal(result, expectedSrc);
   });
+
+  it('should convert define(function(require) {})', function() {
+    var src = fs.readFileSync(path.resolve(__dirname, '../fixtures/amd_with_require.before.js')).toString();
+    var expectedSrc = fs.readFileSync(path.resolve(__dirname, '../fixtures/amd_with_require.after.js')).toString();
+    var result = amdTransform({ source: src }, { jscodeshift: jscodeshift });
+    assert.equal(result, expectedSrc);
+  });
 });

test/utils.js

@@ -281,6 +281,24 @@ describe('util.getRecastConfig', function() {
   });
 })
 
+describe('util.filterRedundantComments', function() {
+  it('should remove comments that already appear in the source comment array', function() {
+    var source = [
+      { value: 'comment one' },
+      { value: 'comment two' },
+      { value: 'comment three' }
+    ];
+
+    var test = [
+      { value: 'comment one' },
+      { value: 'new comment' }
+    ];
+
+    var filtered = utils.filterRedundantComments(source, test);
+    assert.deepEqual(filtered, [{ value: 'new comment' }]);
+  });
+});
+
 /******************************************
  * Test Helpers...
  ******************************************/

transforms/amd.js

@@ -2,12 +2,12 @@
  * amd - Replace define([]) calls with es6 import/exports
  */
 
-var util = require('../utils/main');
+const util = require('../utils/main');
 
 module.exports = function(file, api, options) {
-    var j = api.jscodeshift;
-    var root = j(file.source);
-    var leadingComment = root.find(j.Program).get('body', 0).node.leadingComments;
+    const j = api.jscodeshift;
+    const root = j(file.source);
+    const leadingComment = root.find(j.Program).get('body', 0).node.leadingComments;
 
     /**
      * Convert an `return` to `export default`.
@@ -33,37 +33,67 @@ module.exports = function(file, api, options) {
         .filter(function(p) { return p.parentPath.parentPath.name === 'body'; })
         .forEach(function(p) {
 
-            var body;
-
             // define(function() { });
             if (p.value.arguments.length === 1) {
 
                 // convert `return` statement to `export default`
-                body = returnToExport(p.value.arguments[0].body.body);
+                let body = returnToExport(p.value.arguments[0].body.body);
+
+                let comments = p.parent.value.comments || [];
+
+                // replace any var x = require('x') with import x from 'x';
+                let importStatements = [];
+                body.filter(path => path.type === 'VariableDeclaration')
+                    .forEach(path => {
+                        path.declarations.forEach((d, i) => {
+                            if (d.init
+                                    && d.init.type === 'CallExpression'
+                                    && d.init.callee.name === 'require') {
+                                path.declarations.splice(i, 1);
+                                var moduleName = d.init.arguments[0].value;
+                                var variableName = d.id.name;
+                                importStatements.push(util.createImportStatement(moduleName, variableName));
+                            }
+                        });
+                    });
+
+                // remove any variable declarations which are now empty
+                body = body.filter(path => {
+                    if (path.type !== 'VariableDeclaration') {
+                        return true;
+                    }
+                    return path.declarations.length !== 0;
+                });
+
+                // add the body after the import statements
+                Array.prototype.push.apply(importStatements, body);
 
-                return j(p.parent).replaceWith(body);
+                // add any comments at the top
+                importStatements[0].comments = util.filterRedundantComments(leadingComment, comments);
+
+                return j(p.parent).replaceWith(importStatements);
             }
 
             // define(['a', 'b', 'c'], function(a, b, c) { });
             if (p.value.arguments.length === 2) {
-                var props = p.value.arguments[0].elements;
-                var comments = p.parent.value.comments || [];
-                var importStatements = props.map(function(prop, i) {
-                    var moduleName = prop.value;
-                    var variableName = p.value.arguments[1].params[i] && p.value.arguments[1].params[i].name;
+                let props = p.value.arguments[0].elements;
+                let comments = p.parent.value.comments || [];
+                let importStatements = props.map(function(prop, i) {
+                    let moduleName = prop.value;
+                    let variableName = p.value.arguments[1].params[i] && p.value.arguments[1].params[i].name;
                     return util.createImportStatement(moduleName, variableName);
                 });
 
                 // add the body after the import statements
                 Array.prototype.push.apply(importStatements, p.value.arguments[1].body.body);
 
                 // add any comments at the top
-                importStatements[0].comments = comments;
+                console.log(comments.value);
+                importStatements[0].comments = util.filterRedundantComments(leadingComment, comments);
 
                 // done
                 return j(p.parent).replaceWith(returnToExport(importStatements));
             }
-
         });
 
         // re-add comment to to the top

utils/main.js

@@ -252,6 +252,15 @@ var util = {
 
   hasParentOfType: function(node, type) {
     return util.findParentOfType(node, type) !== false;
+  },
+
+  filterRedundantComments: function(commentsOrig, commentsNew) {
+    if (!commentsOrig || !commentsNew) {
+      // return all comments if there were no original ones
+      return commentsNew;
+    }
+    return commentsNew.filter(comment =>
+        !commentsOrig.some(c => c.value === comment.value));
   }
 };