Add support for mixed ESM and CJS via mixedModules flag (#26)

* Mixded ESM and CJS

* Use 2 spaces

* Remove unused test

* Ignore all `isESM` checks

* Add a flag for `mixedModules`

Author: styfle

node-file-trace.d.ts

@@ -3,6 +3,7 @@ interface NodeFileTraceOptions {
   ignore?: string | string[] | ((path: string) => boolean);
   ts?: boolean;
   log?: boolean;
+  mixedModules?: boolean;
   readFile?: (path: string) => Buffer | string | null;
   stat?: (path: string) => Object | null;
   readlink?: (path: string) => string | null;

src/analyze.js

@@ -222,7 +222,7 @@ module.exports = async function (id, code, job) {
     }
   });
 
-  if (!isESM) {
+  if (!isESM || job.mixedModules) {
     knownBindings.require = {
       shadowDepth: 0,
       value: {
@@ -261,7 +261,7 @@ module.exports = async function (id, code, job) {
     return binding && binding.shadowDepth === 0;
   }
 
-  if (isESM) {
+  if (isESM || job.mixedModules) {
     for (const decl of ast.body) {
       if (decl.type === 'ImportDeclaration') {
         const source = decl.source.value;
@@ -424,13 +424,13 @@ module.exports = async function (id, code, job) {
       // - nodegyp()
       // - etc.
       else if (node.type === 'CallExpression') {
-        if (!isESM && node.callee.type === 'Identifier' && node.arguments.length) {
+        if ((!isESM || job.mixedModules) && node.callee.type === 'Identifier' && node.arguments.length) {
           if (node.callee.name === 'require' && knownBindings.require.shadowDepth === 0) {
             processRequireArg(node.arguments[0]);
             return;
           }
         }
-        else if (!isESM &&
+        else if ((!isESM || job.mixedModules) &&
             node.callee.type === 'MemberExpression' &&
             node.callee.object.type === 'Identifier' &&
             node.callee.object.name === 'module' &&
@@ -615,7 +615,7 @@ module.exports = async function (id, code, job) {
         }
       }
       // Support require wrappers like function p (x) { ...; var y = require(x); ...; return y;  }
-      else if (!isESM &&
+      else if ((!isESM || job.mixedModules) &&
                (node.type === 'FunctionDeclaration' || node.type === 'FunctionExpression' || node.type === 'ArrowFunctionExpression') &&
                (node.arguments || node.params)[0] && (node.arguments || node.params)[0].type === 'Identifier') {
         let fnName, args;

src/node-file-trace.js

@@ -43,7 +43,8 @@ class Job {
   constructor ({
     base = process.cwd(),
     ignore,
-    log = false
+    log = false,
+    mixedModules = false,
   }) {
     base = resolve(base);
     this.ignoreFn = path => {
@@ -68,6 +69,7 @@ class Job {
     }
     this.base = base;
     this.log = log;
+    this.mixedModules = mixedModules;
     this.reasons = Object.create(null);
 
     this.fileCache = new Map();

test/unit.test.js

@@ -29,6 +29,7 @@ for (const unitTest of fs.readdirSync(`${__dirname}/unit`)) {
       base: `${__dirname}/../`,
       ts: true,
       log: true,
+      mixedModules: true,
       ignore: '**/actual.js'
     });
     let expected;

test/unit/mixed-esm-cjs/commonjs-module.js

@@ -0,0 +1 @@
+module.exports = { dep1: 'dep1' };

test/unit/mixed-esm-cjs/ecmascript-module.js

@@ -0,0 +1 @@
+export const dep2 = 'dep2';

test/unit/mixed-esm-cjs/input.js

@@ -0,0 +1,7 @@
+const { dep1 } = require('./commonjs-module');
+import { dep2 } from './ecmascript-module';
+
+if (dep1 && dep2) {
+  console.log(dep1);
+  console.log(dep2);
+}

test/unit/mixed-esm-cjs/output.js

@@ -0,0 +1,5 @@
+[
+    "test/unit/mixed-esm-cjs/commonjs-module.js",
+    "test/unit/mixed-esm-cjs/ecmascript-module.js",
+    "test/unit/mixed-esm-cjs/input.js"
+  ]