Address some PR feedback

src/ReactWrapper.jsx

@@ -13,6 +13,7 @@ import {
   ITERATOR_SYMBOL,
   nodeEqual,
   nodeMatches,
+  getAdapter,
 } from './Utils';
 import {
   debugNodes,
@@ -25,7 +26,6 @@ import {
   treeFilter,
   buildPredicate,
 } from './RSTTraversal';
-import configuration from './configuration';
 
 const noop = () => {};
 
@@ -62,15 +62,6 @@ function getFromRenderer(renderer) {
   };
 }
 
-function getAdapter(options) {
-  if (options.adapter) {
-    return options.adapter;
-  }
-  const adapter = configuration.get().adapter;
-  // TODO(lmr): warn about no adapter being configured
-  return adapter;
-}
-
 /**
  * @class ReactWrapper
  */

src/ShallowWrapper.js

@@ -16,6 +16,7 @@ import {
   isFunctionalComponent,
   isCustomComponentElement,
   ITERATOR_SYMBOL,
+  getAdapter,
 } from './Utils';
 import {
   debugNodes,
@@ -29,7 +30,6 @@ import {
   treeFilter,
   buildPredicate,
 } from './RSTTraversal';
-import configuration from './configuration';
 
 /**
  * Finds all nodes in the current wrapper nodes' render trees that match the provided predicate
@@ -98,15 +98,6 @@ function getRootNode(node) {
   return node.rendered;
 }
 
-function getAdapter(options) {
-  if (options.adapter) {
-    return options.adapter;
-  }
-  const adapter = configuration.get().adapter;
-  // TODO(lmr): warn about no adapter being configured
-  return adapter;
-}
-
 /**
  * @class ShallowWrapper
  */

src/Utils.js

@@ -5,9 +5,31 @@ import is from 'object-is';
 import uuidv4 from 'uuid/v4';
 import entries from 'object.entries';
 import functionName from 'function.prototype.name';
+import configuration from './configuration';
 
 export const ITERATOR_SYMBOL = typeof Symbol === 'function' && Symbol.iterator;
 
+export function getAdapter(options = {}) {
+  if (options.adapter) {
+    return options.adapter;
+  }
+  const adapter = configuration.get().adapter;
+  if (!adapter) {
+    throw new Error(`
+      Enzyme expects an adapter to be configured, but found none. To configure an adapter,
+      you should call \`Enzyme.configure({ adapter: new Adapter() })\` before using any of
+      Enzyme's top level APIs, where \`Adapter\` is the adapter corresponding to the library
+      currently being tested. For example:
+
+      import Adapter from 'enzyme-adapter-react-15';
+
+      To find out more about this, see http://airbnb.io/enzyme/docs/installation/index.html
+    `);
+  }
+  return adapter;
+}
+
+// TODO(lmr): we shouldn't need this
 export function isFunctionalComponent(inst) {
   return !!inst && !!inst.constructor && typeof inst.constructor === 'function' &&
     functionName(inst.constructor) === 'StatelessComponent';

src/adapters/ReactFifteenAdapter.js

@@ -10,6 +10,7 @@ import {
   mapNativeEventNames,
   propFromEvent,
   withSetStateAllowed,
+  assertDomAvailable,
 } from './Utils';
 
 function compositeTypeToNodeType(type) {
@@ -73,6 +74,7 @@ SimpleWrapper.propTypes = { node: PropTypes.node.isRequired };
 
 class ReactFifteenAdapter extends EnzymeAdapter {
   createMountRenderer(options) {
+    assertDomAvailable('mount');
     const domNode = options.attachTo || global.document.createElement('div');
     let instance = null;
     return {

src/adapters/ReactFifteenFourAdapter.js

@@ -10,6 +10,7 @@ import {
   mapNativeEventNames,
   propFromEvent,
   withSetStateAllowed,
+  assertDomAvailable,
 } from './Utils';
 
 function compositeTypeToNodeType(type) {
@@ -73,6 +74,7 @@ SimpleWrapper.propTypes = { node: PropTypes.node.isRequired };
 
 class ReactFifteenFourAdapter extends EnzymeAdapter {
   createMountRenderer(options) {
+    assertDomAvailable('mount');
     const domNode = options.attachTo || global.document.createElement('div');
     let instance = null;
     return {

src/adapters/ReactFourteenAdapter.js

@@ -10,6 +10,7 @@ import {
   mapNativeEventNames,
   propFromEvent,
   withSetStateAllowed,
+  assertDomAvailable,
 } from './Utils';
 
 function typeToNodeType(type) {
@@ -68,6 +69,7 @@ SimpleWrapper.propTypes = { node: PropTypes.node.isRequired };
 
 class ReactFifteenAdapter extends EnzymeAdapter {
   createMountRenderer(options) {
+    assertDomAvailable('mount');
     const domNode = options.attachTo || global.document.createElement('div');
     let instance = null;
     return {

src/adapters/ReactSixteenAdapter.js

@@ -11,6 +11,7 @@ import elementToTree from './elementToTree';
 import {
   mapNativeEventNames,
   propFromEvent,
+  assertDomAvailable,
 } from './Utils';
 
 const HostRoot = 3;
@@ -142,6 +143,7 @@ SimpleWrapper.propTypes = { node: PropTypes.node.isRequired };
 
 class ReactSixteenAdapter extends EnzymeAdapter {
   createMountRenderer(options) {
+    assertDomAvailable('mount');
     const domNode = options.attachTo || global.document.createElement('div');
     let instance = null;
     return {

src/adapters/ReactThirteenAdapter.js

@@ -9,6 +9,7 @@ import {
   mapNativeEventNames,
   propFromEvent,
   withSetStateAllowed,
+  assertDomAvailable,
 } from './Utils';
 
 // this fixes some issues in React 0.13 with setState and jsdom...
@@ -94,6 +95,7 @@ SimpleWrapper.propTypes = { node: PropTypes.node.isRequired };
 
 class ReactThirteenAdapter extends EnzymeAdapter {
   createMountRenderer(options) {
+    assertDomAvailable('mount');
     const domNode = options.attachTo || global.document.createElement('div');
     let instance = null;
     return {

src/adapters/Utils.js

@@ -73,3 +73,11 @@ export function withSetStateAllowed(fn) {
   }
   return result;
 }
+
+export function assertDomAvailable(feature) {
+  if (!global || !global.document || !global.document.createElement) {
+    throw new Error(
+      `Enzyme's ${feature} expects a DOM environment to be loaded, but found none`,
+    );
+  }
+}

test/_helpers/react-compat.js

@@ -4,11 +4,11 @@
   import/prefer-default-export: 0,
 */
 
-import { REACT155, REACT16 } from '../../src/version';
+import { is } from '../../src/version';
 
 let createClass;
 
-if (REACT155 || REACT16) {
+if (is('>=15.5')) {
   // eslint-disable-next-line import/no-extraneous-dependencies
   createClass = require('create-react-class');
 } else {