feat: Support exports (#8)

* support exports

* rename basic case to be more specific

* test variables

* update readme

README.md

@@ -6,8 +6,8 @@ jscodeshift codemod that convert CommonJS(require/exports) to ES Modules(import/
 
 ### Exports
 
-- [x] named export: `module.exports.foo = foo` to `export { foo }`
-- [x] named export: `module.exports.bar = foo` to `export { foo as bar }`
+- [x] named export: `module.exports.foo = foo` & `exports.foo = foo to `export { foo }`
+- [x] named export: `module.exports.bar = foo` & `exports.bar = foo` to `export { foo as bar }`
 - [x] default export: `module.exports = foo` to `export default foo`
 - [x] ignore multiple `module.exports = x`
 

transforms/__testfixtures__/module-exports-to-named-export/basic-case-exports.input.js

@@ -0,0 +1,12 @@
+exports.a = function () {
+  return "a";
+};
+exports.b = function () {
+  return "b";
+};
+
+const c = () => {
+  return 42;
+};
+exports.c = c;
+exports.d = c;

transforms/__testfixtures__/module-exports-to-named-export/basic-case-exports.output.js

@@ -0,0 +1,13 @@
+export const a = function () {
+  return "a";
+};
+
+export const b = function () {
+  return "b";
+};
+
+const c = () => {
+  return 42;
+};
+export { c };
+export { c as d };

transforms/__tests__/module-exports-to-named-export-test.js

@@ -1,6 +1,6 @@
 import { defineTest } from "jscodeshift/dist/testUtils";
 
-const tests = ["basic-case", "exports-variable"];
+const tests = ["basic-case-module-exports", "basic-case-exports", "exports-variable"];
 
 describe("module-exports-to-named-export", () => {
     tests.forEach((test) => {

transforms/module-exports-to-named-export.js

@@ -19,7 +19,8 @@ function transformer(file, api, options) {
 
     // ------------------------------------------------------------------ SEARCH
     // https://astexplorer.net/#/gist/334f5bd39244c7feab38a3fd3cc0ce7f/c332a5b4cbd1a9718e644febf2dce9e9bd032d1b
-    const nodes = j(file.source)
+    const ast = j(file.source)
+    const moduleExportNodes = ast
         .find(j.ExpressionStatement, {
             expression: {
                 left: {
@@ -38,25 +39,42 @@ function transformer(file, api, options) {
         })
         .filter(isTopNode);
 
-    logger.log(`${nodes.length} nodes will be transformed`);
-
-    // ----------------------------------------------------------------- REPLACE
-    return nodes
-        .replaceWith((path) => {
-            const node = path.node;
-            // Identifier node
-            const id = node.expression.left.property;
-            const init = node.expression.right;
-            // module.export.b = a
-            // → export { a as b }
-            if (id.type === "Identifier" && init.type === "Identifier") {
-                return j.exportNamedDeclaration(null, [j.exportSpecifier(init, id)]);
+    const exportNodes = ast
+        .find(j.ExpressionStatement, {
+            expression: {
+                left: {
+                    object: {
+                        name: "exports"
+                    }
+                    // property is target
+                },
+                operator: "="
             }
-            // https://babeljs.io/docs/en/babel-types#exportnameddeclaration
-            const declaration = j.variableDeclaration("const", [j.variableDeclarator(id, init)]);
-            return j.exportNamedDeclaration(declaration);
         })
-        .toSource();
+        .filter(isTopNode);
+
+    logger.log(`${moduleExportNodes.length + exportNodes.length} nodes will be transformed`);
+    // ----------------------------------------------------------------- REPLACE
+    const replace = (path) => {
+        const node = path.node;
+        // Identifier node
+        const id = node.expression.left.property;
+        const init = node.expression.right;
+        // module.export.b = a
+        // → export { a as b }
+        if (id.type === "Identifier" && init.type === "Identifier") {
+            return j.exportNamedDeclaration(null, [j.exportSpecifier(init, id)]);
+        }
+        // https://babeljs.io/docs/en/babel-types#exportnameddeclaration
+        const declaration = j.variableDeclaration("const", [j.variableDeclarator(id, init)]);
+        return j.exportNamedDeclaration(declaration);
+    }
+
+    exportNodes
+        .replaceWith(replace)
+    moduleExportNodes
+        .replaceWith(replace)
+    return ast.toSource();
 }
 
 export default transformer;