fix: do not register the plugin twice

Author: anshumanv

src/plugin.js

@@ -1,9 +1,5 @@
 /* eslint-disable consistent-return */
 /* eslint-disable no-useless-escape */
-const path = require('path');
-
-const { createFsFromVolume, Volume } = require('memfs');
-const webpack = require('webpack');
 
 const installer = require('./installer');
 const utils = require('./utils');
@@ -48,9 +44,6 @@ class NpmInstallPlugin {
   apply(compiler) {
     this.compiler = compiler;
 
-    // Recursively install missing dependencies so primary build doesn't fail
-    compiler.hooks.watchRun.tapAsync(PLUGIN_NAME, this.preCompile.bind(this));
-
     // Install externals that wouldn't normally be resolved
     if (Array.isArray(compiler.options.externals)) {
       compiler.options.externals.unshift(this.resolveExternal.bind(this));
@@ -97,28 +90,6 @@ class NpmInstallPlugin {
     }
   }
 
-  preCompile(compilation, next) {
-    if (!this.preCompiler) {
-      const { options } = this.compiler;
-      const config = Object.assign(
-        // Start with new config object
-        {},
-        // Inherit the current config
-        options,
-        {
-          // Register plugin to install missing deps
-          plugins: [new NpmInstallPlugin(this.options)],
-        }
-      );
-
-      this.preCompiler = webpack(config);
-      this.preCompiler.outputFileSystem = createFsFromVolume(new Volume());
-      this.preCompiler.outputFileSystem.join = path.join.bind(path);
-    }
-
-    this.preCompiler.run(next);
-  }
-
   resolveExternal(context, request, callback) {
     // Only install direct dependencies, not sub-dependencies
     if (context.match('node_modules')) {

test/plugin.test.js

@@ -56,33 +56,6 @@ describe('plugin', () => {
     });
   });
 
-  describe('.preCompile', () => {
-    beforeEach(() => {
-      this.run = jest
-        .spyOn(webpack.Compiler.prototype, 'run')
-        .mockImplementation((callback) => {
-          callback();
-        });
-    });
-
-    afterEach(() => {
-      this.run.mockRestore();
-    });
-
-    it('should perform dryrun', (done) => {
-      const compilation = {};
-
-      this.plugin.preCompile(
-        compilation,
-        // eslint-disable-next-line
-        function () {
-          expect(this.run).toHaveBeenCalled();
-          done();
-        }.bind(this)
-      );
-    });
-  });
-
   describe('.resolveExternal', () => {
     beforeEach(() => {
       this.resolve = jest