fix: add debug logs for unresolvable plugins (#74)

* fix: add debug logs for unresolvable plugins

and remove the need for "lib/isPlugin.js"

also, add test for undefined $NODE_PATH edge case

* fix: add debug log for plugins missing a "register" export

And remove the `require.resolve` check.

lib/__tests__/__snapshots__/findPlugins.js.snap

@@ -1,5 +1,12 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`findPlugins falls back to (npm root -g) when $NODE_PATH is empty 1`] = `
+Map {
+  "meta-1" => "/npm/root/meta-1",
+  "meta-2" => "/npm/root/@foo/meta-2",
+}
+`;
+
 exports[`findPlugins finds non-scoped plugins 1`] = `
 Map {
   "meta-foo" => "/node_modules/meta-foo",

lib/__tests__/findPlugins.js

@@ -1,10 +1,7 @@
 jest.mock('fs');
-jest.mock('../isPlugin', () => {
-  const path = require('path');
-  return filePath => /^meta-/.test(path.basename(filePath));
-});
 
 const findPlugins = require('../findPlugins');
+const cp = require('child_process');
 const fs = require('fs');
 
 describe('findPlugins', () => {
@@ -52,6 +49,18 @@ describe('findPlugins', () => {
     expect(findPlugins('/dev')).toMatchSnapshot();
   });
 
+  it('falls back to (npm root -g) when $NODE_PATH is empty', () => {
+    fs.write('/npm/root/foo/index.js', '');
+    fs.write('/npm/root/meta-1/index.js', '');
+    fs.write('/npm/root/@foo/meta-2/index.js', '');
+
+    delete process.env.NODE_PATH;
+    cp.execSync = jest.fn(() => '/npm/root');
+
+    expect(findPlugins('/')).toMatchSnapshot();
+    expect(cp.execSync.mock.calls).toEqual([['npm root -g']]);
+  });
+
   it('tolerates missing "node_modules" when searching parent directories', () => {
     fs.write('/1/node_modules/meta-1/index.js', '');
     fs.write('/1/2/3/node_modules/meta-3/index.js', '');

lib/findPlugins.js

@@ -2,7 +2,6 @@ const cp = require('child_process');
 const debug = require('debug')('meta:findPlugins');
 const fs = require('fs');
 const path = require('path');
-const isPlugin = require('./isPlugin');
 
 /**
  * Meta's custom plugin resolution logic
@@ -38,10 +37,7 @@ module.exports = (cwd, searchDir = 'node_modules') => {
 };
 
 function getDefaultGlobalRoot() {
-  return cp
-    .execSync('npm root -g')
-    .toString()
-    .trim();
+  return (cp.execSync('npm root -g') + '').trim();
 }
 
 /** Check a directory for potentially-scoped /^meta-/ packages */
@@ -54,9 +50,9 @@ function findNearbyPlugins(cwd, onPlugin) {
         const scopePath = filePath;
         fs.readdirSync(scopePath).forEach(name => {
           const filePath = path.join(scopePath, name);
-          if (isPlugin(filePath)) onPlugin(name, filePath);
+          if (/^meta-/.test(name)) onPlugin(name, filePath);
         });
-      } else if (isPlugin(filePath)) {
+      } else if (/^meta-/.test(name)) {
         onPlugin(name, filePath);
       }
     });

lib/registerPlugin.js

@@ -1,9 +1,11 @@
 const debug = require('debug')('meta:registerPlugin');
 
-module.exports = (program, mod) => {
-  const plugin = require(mod);
-  if (plugin.register) {
-    debug(`registering plugin ${mod}`);
+module.exports = (program, pluginPath) => {
+  plugin = require(pluginPath);
+  if (typeof plugin.register === 'function') {
+    debug(`Registering plugin: '${pluginPath}'`);
     plugin.register(program);
+  } else {
+    debug(`Plugin has no "register" function: '${pluginPath}'`);
   }
 };