diff --git a/packages/angular-cli/lib/config/schema.json b/packages/angular-cli/lib/config/schema.json
index e5f28d42b270..3a2a1f02fcc9 100644
--- a/packages/angular-cli/lib/config/schema.json
+++ b/packages/angular-cli/lib/config/schema.json
@@ -59,7 +59,8 @@
             "type": "string"
           },
           "tsconfig": {
-            "type": "string"
+            "type": "string",
+            "default": "tsconfig.json"
           },
           "prefix": {
             "type": "string"
diff --git a/packages/angular-cli/models/json-schema/schema-tree.ts b/packages/angular-cli/models/json-schema/schema-tree.ts
index 2dd120a22788..2b80057b6424 100644
--- a/packages/angular-cli/models/json-schema/schema-tree.ts
+++ b/packages/angular-cli/models/json-schema/schema-tree.ts
@@ -134,9 +134,11 @@ export abstract class NonLeafSchemaTreeNode<T> extends SchemaTreeNode<T> {
     if (!schema['oneOf']) {
       type = schema['type'];
     } else {
+      let testValue = value || schema['default'];
+      // Match existing value to one of the schema types
       for (let testSchema of schema['oneOf']) {
-        if ((testSchema['type'] === 'array' && Array.isArray(value))
-            || typeof value === testSchema['type']) {
+        if ((testSchema['type'] === 'array' && Array.isArray(testValue))
+            || typeof testValue === testSchema['type']) {
           type = testSchema['type'];
           schema = testSchema;
           break;
diff --git a/packages/angular-cli/models/webpack-build-common.ts b/packages/angular-cli/models/webpack-build-common.ts
index cd0465ea2335..6130f887fbc0 100644
--- a/packages/angular-cli/models/webpack-build-common.ts
+++ b/packages/angular-cli/models/webpack-build-common.ts
@@ -46,12 +46,8 @@ export function getWebpackCommonConfig(
     main: [appMain]
   };
 
-  if (!(environment in appConfig.environments)) {
-    throw new SilentError(`Environment "${environment}" does not exist.`);
-  }
-
   // process global scripts
-  if (appConfig.scripts.length > 0) {
+  if (appConfig.scripts && appConfig.scripts.length > 0) {
     const globalScripts = extraEntryParser(appConfig.scripts, appRoot, 'scripts');
 
     // add entry points and lazy chunks
@@ -67,7 +63,7 @@ export function getWebpackCommonConfig(
   }
 
   // process global styles
-  if (appConfig.styles.length === 0) {
+  if (!appConfig.styles || appConfig.styles.length === 0) {
     // create css loaders for component css
     extraRules.push(...makeCssLoaders());
   } else {
@@ -104,6 +100,33 @@ export function getWebpackCommonConfig(
     }));
   }
 
+  // process environment file replacement
+  if (appConfig.environments) {
+    if (!('source' in appConfig.environments)) {
+      throw new SilentError(`Environment configuration does not contain "source" entry.`);
+    }
+    if (!(environment in appConfig.environments)) {
+      throw new SilentError(`Environment "${environment}" does not exist.`);
+    }
+
+    extraPlugins.push(new webpack.NormalModuleReplacementPlugin(
+      // This plugin is responsible for swapping the environment files.
+      // Since it takes a RegExp as first parameter, we need to escape the path.
+      // See https://webpack.github.io/docs/list-of-plugins.html#normalmodulereplacementplugin
+      new RegExp(path.resolve(appRoot, appConfig.environments['source'])
+        .replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, '\\$&')),
+      path.resolve(appRoot, appConfig.environments[environment])
+    ));
+  }
+
+  // process asset entries
+  if (appConfig.assets) {
+    extraPlugins.push(new GlobCopyWebpackPlugin({
+      patterns: appConfig.assets,
+      globOptions: { cwd: appRoot, dot: true, ignore: '**/.gitkeep' }
+    }));
+  }
+
   if (progress) { extraPlugins.push(new ProgressPlugin({ profile: verbose, colors: true })); }
 
   return {
@@ -145,22 +168,10 @@ export function getWebpackCommonConfig(
       new BaseHrefWebpackPlugin({
         baseHref: baseHref
       }),
-      new webpack.NormalModuleReplacementPlugin(
-        // This plugin is responsible for swapping the environment files.
-        // Since it takes a RegExp as first parameter, we need to escape the path.
-        // See https://webpack.github.io/docs/list-of-plugins.html#normalmodulereplacementplugin
-        new RegExp(path.resolve(appRoot, appConfig.environments['source'])
-          .replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, '\\$&')),
-        path.resolve(appRoot, appConfig.environments[environment])
-      ),
       new webpack.optimize.CommonsChunkPlugin({
         minChunks: Infinity,
         name: 'inline'
       }),
-      new GlobCopyWebpackPlugin({
-        patterns: appConfig.assets,
-        globOptions: { cwd: appRoot, dot: true, ignore: '**/.gitkeep' }
-      }),
       new webpack.LoaderOptionsPlugin({
         test: /\.(css|scss|sass|less|styl)$/,
         options: {
diff --git a/packages/angular-cli/models/webpack-build-typescript.ts b/packages/angular-cli/models/webpack-build-typescript.ts
index 67940af47ab8..0e7ba7807aa6 100644
--- a/packages/angular-cli/models/webpack-build-typescript.ts
+++ b/packages/angular-cli/models/webpack-build-typescript.ts
@@ -9,6 +9,8 @@ const webpackLoader: string = g['angularCliIsLocal']
 
 
 export const getWebpackNonAotConfigPartial = function(projectRoot: string, appConfig: any) {
+  let exclude = [ '**/*.spec.ts' ];
+  if (appConfig.test) { exclude.push(path.join(projectRoot, appConfig.root, appConfig.test)); };
   return {
     module: {
       rules: [
@@ -23,10 +25,7 @@ export const getWebpackNonAotConfigPartial = function(projectRoot: string, appCo
       new AotPlugin({
         tsConfigPath: path.resolve(projectRoot, appConfig.root, appConfig.tsconfig),
         mainPath: path.join(projectRoot, appConfig.root, appConfig.main),
-        exclude: [
-          path.join(projectRoot, appConfig.root, appConfig.test),
-          '**/*.spec.ts'
-        ],
+        exclude: exclude,
         skipCodeGeneration: true
       }),
     ]
@@ -35,6 +34,8 @@ export const getWebpackNonAotConfigPartial = function(projectRoot: string, appCo
 
 export const getWebpackAotConfigPartial = function(projectRoot: string, appConfig: any,
   i18nFile: string, i18nFormat: string, locale: string) {
+  let exclude = [ '**/*.spec.ts' ];
+  if (appConfig.test) { exclude.push(path.join(projectRoot, appConfig.root, appConfig.test)); };
   return {
     module: {
       rules: [
@@ -52,10 +53,7 @@ export const getWebpackAotConfigPartial = function(projectRoot: string, appConfi
         i18nFile: i18nFile,
         i18nFormat: i18nFormat,
         locale: locale,
-        exclude: [
-          path.join(projectRoot, appConfig.root, appConfig.test),
-          '**/*.spec.ts'
-        ]
+        exclude: exclude
       })
     ]
   };
diff --git a/packages/angular-cli/tasks/serve-webpack.ts b/packages/angular-cli/tasks/serve-webpack.ts
index 6b491071be97..42fe588e677e 100644
--- a/packages/angular-cli/tasks/serve-webpack.ts
+++ b/packages/angular-cli/tasks/serve-webpack.ts
@@ -98,7 +98,8 @@ export default Task.extend({
       proxy: proxyConfig,
       compress: serveTaskOptions.target === 'production',
       watchOptions: {
-        poll: CliConfig.fromProject().config.defaults.poll
+        poll: CliConfig.fromProject().config.defaults &&
+          CliConfig.fromProject().config.defaults.poll
       },
       https: serveTaskOptions.ssl
     };
diff --git a/tests/e2e/tests/misc/minimal-config.ts b/tests/e2e/tests/misc/minimal-config.ts
new file mode 100644
index 000000000000..20b8591263c5
--- /dev/null
+++ b/tests/e2e/tests/misc/minimal-config.ts
@@ -0,0 +1,14 @@
+import { writeFile } from '../../utils/fs';
+import { ng } from '../../utils/process';
+
+
+export default function () {
+  return Promise.resolve()
+    .then(() => writeFile('angular-cli.json', JSON.stringify({
+      apps: [{
+        root: 'src',
+        main: 'main.ts'
+      }]
+    })))
+    .then(() => ng('build'));
+}