[Fix] do not crash on dynamic requires

Fixes #47.

Author: ljharb

src/index.js

@@ -23,6 +23,9 @@ let ignoreRegex;
 
 export default ({ types: t }) => {
   function applyPlugin(importIdentifier, importPath, path, state) {
+    if (typeof importPath !== 'string') {
+      throw new TypeError('`applyPlugin` `importPath` must be a string');
+    }
     const { ignorePattern, caseSensitive } = state.opts;
     const { file } = state;
     if (ignorePattern) {
@@ -110,8 +113,9 @@ export default ({ types: t }) => {
       },
       CallExpression(path, state) {
         const { node } = path;
-        const filePath = node.arguments.length > 0 && node.arguments[0].value;
-        if (node.callee.name === 'require' && t.isVariableDeclarator(path.parent)) {
+        const requireArg = node.arguments.length > 0 ? node.arguments[0] : null;
+        const filePath = t.isStringLiteral(requireArg) ? requireArg.value : null;
+        if (node.callee.name === 'require' && t.isVariableDeclarator(path.parent) && filePath) {
           applyPlugin(path.parent.id, filePath, path.parentPath.parentPath, state);
         }
       },

test/fixtures/test-dynamic-require.jsx

@@ -0,0 +1,15 @@
+import React from 'react';
+
+const MySvg = require('./close.svg');
+
+export const foo = require(path.join(pkgBase, 'package.json')); // regression test
+
+export default function MyFunctionIcon() {
+  return <MySvg />;
+}
+
+export class MyClassIcon extends React.Component {
+  render() {
+    return <MySvg />;
+  }
+}

test/fixtures/test-import.jsx

@@ -1,7 +1,7 @@
 import React from 'react';
 import MySvg from './close.svg';
 
-export function MyFunctionIcon() {
+export default function MyFunctionIcon() {
   return <MySvg />;
 }
 

test/fixtures/test-require.jsx

@@ -2,7 +2,7 @@ import React from 'react';
 
 const MySvg = require('./close.svg');
 
-export function MyFunctionIcon() {
+export default function MyFunctionIcon() {
   return <MySvg />;
 }
 

test/sanity.js

@@ -111,3 +111,13 @@ transformFile('test/fixtures/test-import.jsx', {
     }
   });
 });
+
+transformFile('test/fixtures/test-dynamic-require.jsx', {
+  presets: ['airbnb'],
+  plugins: [
+    '../../src/index',
+  ],
+}, (err, result) => {
+  if (err) throw err;
+  console.log('test/fixtures/test-dynamic-require.jsx', result.code);
+});