refactor: switch from standard-things/esm to native

BREAKING CHANGE: now if you want to use `.mjs` files, you should run
with `NODE_OPTIONS=--experimental-modules` on Node 12.x+.  Also, native
ES module loading is NOT compatible with coffeescript/register

Fixes: #11

.eslintignore

@@ -1,2 +1,3 @@
 /node_modules
 /tmp
+/lib/esm/import.js

lib/esm/import.js

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2019, Groupon
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * Neither the name of GROUPON nor the names of its contributors may be
+ * used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+'use strict';
+
+// put this in its own file so that it can barf on require if needed
+
+/**
+ * @param {string} id
+ * @returns {Promise<any>}
+ */
+module.exports = id => import(id);

lib/esm/index.js

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2019, Groupon
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * Neither the name of GROUPON nor the names of its contributors may be
+ * used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+'use strict';
+
+const debug = require('debug')('esm');
+
+/** @type {(id: string) => Promise<any>} */
+let importESM;
+try {
+  importESM = require('./import');
+} catch (err) {
+  debug('failed to load esm import: ', err);
+  importESM = () => Promise.reject(err);
+}
+
+exports.importESM = importESM;
+exports.supportsESM = () =>
+  importESM('../../package.json').then(() => true, () => false);

lib/project.js

@@ -35,11 +35,10 @@
 const path = require('path');
 const Module = require('module');
 const util = require('util');
+const { URL } = require('url');
 
 const debug = require('debug')('nilo:project');
 // @ts-ignore
-const esm = require('esm');
-// @ts-ignore
 const globCallback = require('glob');
 
 const glob = util.promisify(globCallback);
@@ -48,27 +47,18 @@ const glob = util.promisify(globCallback);
 const rawModulePaths = Module['_nodeModulePaths'];
 const getModulePaths = /** @type {(from: string) => string[]} */ (rawModulePaths);
 
+const { importESM } = require('./esm');
+
 /**
- * @typedef {import('./typedefs').InterfaceFile} InterfaceFile
+ * @param {string} reSTR
  */
+function escapeRE(reSTR) {
+  return reSTR.replace(/[$^*()+\[\]{}\\|.?]/g, '\\$&');
+}
 
 /**
- * @param {object} esmResult
- * @param {string} specifier
+ * @typedef {import('./typedefs').InterfaceFile} InterfaceFile
  */
-function guessNamespace(esmResult, specifier) {
-  if (specifier.endsWith('.mjs')) return esmResult;
-
-  // "Heuristic" to figure out if it kinda looks like a namespace
-  if (
-    esmResult !== null &&
-    typeof esmResult === 'object' &&
-    'default' in esmResult
-  )
-    return esmResult;
-
-  return { default: esmResult };
-}
 
 class Project {
   /**
@@ -91,27 +81,12 @@ class Project {
     this._pkgJson = null;
     this._globCache = {};
     this._globStatCache = {};
-
-    this._importESM = esm(this.app, {
-      cjs: {
-        cache: false,
-        esModule: false,
-        extensions: false,
-        mutableNamespace: false,
-        namedExports: false,
-        paths: false,
-        vars: false,
-        dedefault: false,
-        topLevelReturn: false,
-      },
-      mode: 'strict',
-    });
   }
 
   /**
    * @param {string} pattern
    * @param {object} [options]
-   * @returns {string[]}
+   * @returns {Promise<string[]>}
    */
   cachedGlob(pattern, options = {}) {
     return glob(
@@ -188,9 +163,22 @@ class Project {
    * @param {string} id
    * @returns {Promise<unknown>}
    */
-  import(id) {
-    const esmResult = this._importESM(id);
-    return guessNamespace(esmResult, id);
+  async import(id) {
+    debug('import', id);
+    // if it's a package spec, assume we can't load it as a ES module
+    // for now
+    if (!/^(\.\.?)?\//.test(id)) return { default: this.require(id) };
+
+    try {
+      return await importESM(
+        /^\.\.?\//.test(id)
+          ? new URL(id, `file://${this.app.filename}`).toString()
+          : id
+      );
+    } catch (err) {
+      if (err.message !== 'Not supported') throw err;
+      return { default: this.require(id) };
+    }
   }
 
   /**
@@ -204,7 +192,8 @@ class Project {
       // Still throw errors unrelated to finding the module
       if (e.code !== 'MODULE_NOT_FOUND') throw e;
       // Do *not* ignore failing requires of subsequent files
-      if (!e.message.includes(`'${id}'`)) throw e;
+      const re = new RegExp(`(^|[\\s'"])${escapeRE(id)}([\\s'"]|$)`);
+      if (!re.test(e.message)) throw e;
 
       return null;
     }

package.json

@@ -28,7 +28,6 @@
   "dependencies": {
     "commander": "^2.19.0",
     "debug": "^4.1.1",
-    "esm": "^3.2.20",
     "glob": "^7.1.3"
   },
   "devDependencies": {

test/project.test.js

@@ -9,6 +9,7 @@ const mkdirp = require('mkdirp');
 const tmp = require('tmp');
 
 const { Project } = require('../');
+const { supportsESM } = require('../lib/esm');
 
 const FRAMEWORK_DIR = path.resolve(__dirname, '..');
 
@@ -34,7 +35,7 @@ describe('Project', () => {
     let project;
     /** @type {import('tmp').SynchrounousResult} */
     let tmpHandle;
-    before(() => {
+    before(async () => {
       tmpHandle = tmp.dirSync({ unsafeCleanup: true });
       project = new Project(tmpHandle.name, FRAMEWORK_DIR);
 
@@ -55,11 +56,13 @@ describe('Project', () => {
 
 module.exports = 'from lib1';
 `,
-        'modules/mod1/everywhere.mjs': `\
+      };
+      if (await supportsESM()) {
+        files['modules/mod1/everywhere.mjs'] = `\
 export default 'from mod1';
 export const namedExport = 'forwarded';
-`,
-      };
+`;
+      }
       const pkgNames = ['@some-scope/pkg1', 'dev-dep1', 'hoisted', 'pkg2'];
       for (const pkgName of pkgNames) {
         files[`node_modules/${pkgName}/everywhere.js`] = `\
@@ -83,11 +86,23 @@ module.exports = 'from ${pkgName}';
       if (tmpHandle) tmpHandle.removeCallback();
     });
 
+    afterEach(() => {
+      // @ts-ignore
+      project['_globCache'] = {};
+      // @ts-ignore
+      project['_globStatCache'] = {};
+    });
+
     /**
      * @param {{ specifier: string, [key: string]: any }[]} expected
      * @param {{ specifier: string, [key: string]: any }[]} actual
      */
     function sortedEqual(expected, actual) {
+      // native es modules return a namespace which isn't an ordinary object,
+      // which makes mocha barf on diffing
+      for (const a of actual) {
+        if (a.moduleNamespace) a.moduleNamespace = { ...a.moduleNamespace };
+      }
       assert.deepStrictEqual(
         sortBy(actual, 'specifier'),
         sortBy(expected, 'specifier')
@@ -108,15 +123,19 @@ module.exports = 'from ${pkgName}';
               moduleNamespace: { default: 'from lib1' },
               defaultExport: 'from lib1',
             },
-            {
-              specifier: './modules/mod1/everywhere.mjs',
-              group: 'mod1',
-              moduleNamespace: {
-                default: 'from mod1',
-                namedExport: 'forwarded',
-              },
-              defaultExport: 'from mod1',
-            },
+            ...((await supportsESM())
+              ? [
+                  {
+                    specifier: './modules/mod1/everywhere.mjs',
+                    group: 'mod1',
+                    moduleNamespace: {
+                      default: 'from mod1',
+                      namedExport: 'forwarded',
+                    },
+                    defaultExport: 'from mod1',
+                  },
+                ]
+              : []),
             {
               specifier: '@some-scope/pkg1/everywhere',
               group: 'pkg1',
@@ -139,15 +158,19 @@ module.exports = 'from ${pkgName}';
               moduleNamespace: { default: 'from lib1' },
               defaultExport: 'from lib1',
             },
-            {
-              specifier: './modules/mod1/everywhere.mjs',
-              group: 'mod1',
-              moduleNamespace: {
-                default: 'from mod1',
-                namedExport: 'forwarded',
-              },
-              defaultExport: 'from mod1',
-            },
+            ...((await supportsESM())
+              ? [
+                  {
+                    specifier: './modules/mod1/everywhere.mjs',
+                    group: 'mod1',
+                    moduleNamespace: {
+                      default: 'from mod1',
+                      namedExport: 'forwarded',
+                    },
+                    defaultExport: 'from mod1',
+                  },
+                ]
+              : []),
             {
               specifier: '@some-scope/pkg1/everywhere',
               group: 'pkg1',