feat(autoinstall): Add disabling of autoinstall globally via environm…

packages/core/integration-tests/test/integration/dont-autoinstall-if-env-var-is-false/.env

@@ -0,0 +1 @@
+PARCEL_AUTOINSTALL=false

packages/core/integration-tests/test/integration/dont-autoinstall-if-env-var-is-false/index.js

@@ -0,0 +1,4 @@
+const _ = require('lodash');
+module.exports = function() {
+  return 'hello world';
+}

packages/core/integration-tests/test/integration/dont-autoinstall-if-env-var-is-false/package.json

@@ -0,0 +1,4 @@
+{
+  "name": "dont-autoinstall-if-env-var-is-false",
+  "dependencies": {}
+}

packages/core/integration-tests/test/javascript.js

@@ -50,6 +50,28 @@ describe('javascript', function() {
     assert.equal(output.default(), 3);
   });
 
+  it('should not autoinstall if PARCEL_AUTOINSTALL is set to false', async function() {
+    const inputDir = path.join(
+      __dirname,
+      '/integration/dont-autoinstall-if-env-var-is-false/'
+    );
+    try {
+      let a = await bundle(path.resolve(inputDir, './index.js'));
+      await run(a);
+    } catch (e) {
+      let pkg = await fs.readFile(
+        path.resolve(inputDir, 'package.json'),
+        'utf8'
+      );
+      const pkgName = 'lodash';
+      pkg = JSON.parse(pkg);
+      assert(pkgName in pkg.dependencies === false);
+      assert(e.message.includes("Cannot resolve dependency 'lodash'"));
+    }
+
+    delete process.env.PARCEL_AUTOINSTALL;
+  });
+
   it('should auto install babel-core v6', async function() {
     let originalPkg = await fs.readFile(
       __dirname + '/integration/babel-6-autoinstall/package.json'

packages/core/parcel-bundler/src/Bundler.js

@@ -142,9 +142,11 @@ class Bundler extends EventEmitter {
       detailedReport: options.detailedReport || false,
       global: options.global,
       autoinstall:
-        typeof options.autoinstall === 'boolean'
-          ? options.autoinstall
-          : !isProduction,
+        typeof options.autoInstall === 'boolean'
+          ? options.autoInstall
+          : process.env.PARCEL_AUTOINSTALL === 'false'
+            ? false
+            : !isProduction,
       scopeHoist: scopeHoist,
       contentHash:
         typeof options.contentHash === 'boolean'