diff --git a/test/function/custom-external-resolver-async/_config.js b/test/function/custom-external-resolver-async/_config.js
index 34faf37..50e54fa 100644
--- a/test/function/custom-external-resolver-async/_config.js
+++ b/test/function/custom-external-resolver-async/_config.js
@@ -5,9 +5,11 @@ var Promise = require( 'sander' ).Promise;
 module.exports = {
 	description: 'uses a custom external path resolver (asynchronous)',
 	options: {
-		resolveExternal: function ( id, importer, options ) {
-			return Promise.resolve( path.resolve( __dirname, 'js_modules', id + '.js' ) );
-		}
+		plugins: [{
+			resolveId: function ( id, importer ) {
+				if ( importer && id[0] !== '.' ) return Promise.resolve( path.resolve( __dirname, 'js_modules', id + '.js' ) );
+			}
+		}]
 	},
 	exports: function ( exports ) {
 		assert.ok( exports.success );
diff --git a/test/function/custom-external-resolver-sync/_config.js b/test/function/custom-external-resolver-sync/_config.js
index 2cf6de7..859c36d 100644
--- a/test/function/custom-external-resolver-sync/_config.js
+++ b/test/function/custom-external-resolver-sync/_config.js
@@ -4,9 +4,11 @@ var assert = require( 'assert' );
 module.exports = {
 	description: 'uses a custom external path resolver (synchronous)',
 	options: {
-		resolveExternal: function ( id, importer, options ) {
-			return path.resolve( __dirname, 'js_modules', id + '.js' );
-		}
+		plugins: [{
+			resolveId: function ( id, importer ) {
+				if ( importer && id[0] !== '.' ) return path.resolve( __dirname, 'js_modules', id + '.js' );
+			}
+		}]
 	},
 	exports: function ( exports ) {
 		assert.ok( exports.success );
diff --git a/test/function/custom-loaders/_config.js b/test/function/custom-loaders/_config.js
index 17e2b79..cd18c7a 100644
--- a/test/function/custom-loaders/_config.js
+++ b/test/function/custom-loaders/_config.js
@@ -3,15 +3,19 @@ var fs = require( 'fs' );
 module.exports = {
 	description: 'uses custom loaders, falling back to default',
 	options: {
-		load: [
-			function ( id ) {
-				if ( /foo\.js/.test( id ) ) {
-					return fs.readFileSync( id, 'utf-8' ).replace( '@', 1 );
+		plugins: [
+			{
+				load: function ( id ) {
+					if ( /foo\.js/.test( id ) ) {
+						return fs.readFileSync( id, 'utf-8' ).replace( '@', 1 );
+					}
 				}
 			},
-			function ( id ) {
-				if ( /bar\.js/.test( id ) ) {
-					return fs.readFileSync( id, 'utf-8' ).replace( '@', 2 );
+			{
+				load: function ( id ) {
+					if ( /bar\.js/.test( id ) ) {
+						return fs.readFileSync( id, 'utf-8' ).replace( '@', 2 );
+					}
 				}
 			}
 		]
diff --git a/test/function/custom-path-resolver-async/_config.js b/test/function/custom-path-resolver-async/_config.js
index c336d67..2d7539a 100644
--- a/test/function/custom-path-resolver-async/_config.js
+++ b/test/function/custom-path-resolver-async/_config.js
@@ -4,20 +4,22 @@ var assert = require( 'assert' );
 module.exports = {
 	description: 'uses a custom path resolver (asynchronous)',
 	options: {
-		resolveId: function ( importee, importer ) {
-			var Promise = require( 'sander' ).Promise;
-			var resolved;
+		plugins: [{
+			resolveId: function ( importee, importer ) {
+				var Promise = require( 'sander' ).Promise;
+				var resolved;
 
-			if ( path.normalize(importee) === path.resolve( __dirname, 'main.js' ) ) return importee;
+				if ( path.normalize(importee) === path.resolve( __dirname, 'main.js' ) ) return importee;
 
-			if ( importee === 'foo' ) {
-				resolved = path.resolve( __dirname, 'bar.js' );
-			} else {
-				resolved = false;
-			}
+				if ( importee === 'foo' ) {
+					resolved = path.resolve( __dirname, 'bar.js' );
+				} else {
+					resolved = false;
+				}
 
-			return Promise.resolve( resolved );
-		}
+				return Promise.resolve( resolved );
+			}
+		}]
 	},
 	exports: function ( exports ) {
 		assert.strictEqual( exports.path, require( 'path' ) );
diff --git a/test/function/custom-path-resolver-on-entry/_config.js b/test/function/custom-path-resolver-on-entry/_config.js
index 5a983b2..0766b6c 100644
--- a/test/function/custom-path-resolver-on-entry/_config.js
+++ b/test/function/custom-path-resolver-on-entry/_config.js
@@ -10,22 +10,24 @@ module.exports = {
 	description: 'applies custom resolver to entry point',
 	//solo: true,
 	options: {
-		resolveId: function ( importee, importer ) {
-			if ( importer === undefined ) {
-				return '@' + path.relative( __dirname, importee );
-			}
+		plugins: [{
+			resolveId: function ( importee, importer ) {
+				if ( importer === undefined ) {
+					return '@' + path.relative( __dirname, importee );
+				}
 
-			if ( importer[0] === '@' ) {
-				return path.resolve( __dirname, importee ) + '.js';
-			}
-		},
-		load: function ( moduleId ) {
-			if ( moduleId[0] === '@' ) {
-				return cachedModules[ moduleId ];
-			}
+				if ( importer[0] === '@' ) {
+					return path.resolve( __dirname, importee ) + '.js';
+				}
+			},
+			load: function ( moduleId ) {
+				if ( moduleId[0] === '@' ) {
+					return cachedModules[ moduleId ];
+				}
 
-			return fs.readFileSync( moduleId, 'utf-8' );
-		}
+				return fs.readFileSync( moduleId, 'utf-8' );
+			}
+		}]
 	},
 	exports: function ( exports ) {
 		assert.equal( exports, 42 );
diff --git a/test/function/custom-path-resolver-plural-b/_config.js b/test/function/custom-path-resolver-plural-b/_config.js
index 60a4d26..05cf37a 100644
--- a/test/function/custom-path-resolver-plural-b/_config.js
+++ b/test/function/custom-path-resolver-plural-b/_config.js
@@ -3,17 +3,21 @@ var assert = require( 'assert' );
 module.exports = {
 	description: 'resolver error is not caught',
 	options: {
-		resolveId: [
-			function () {
-				throw new Error( 'nope' );
+		plugins: [
+			{
+				resolveId: function () {
+					throw new Error( 'nope' );
+				},
+				load: function ( id ) {
+					if ( id === 'main' ) return 'assert.ok( false );'
+				}
 			},
-			function ( importee, importer ) {
-				return 'main';
+			{
+				resolveId: function ( importee, importer ) {
+					return 'main';
+				}
 			}
-		],
-		load: function ( id ) {
-			if ( id === 'main' ) return 'assert.ok( false );'
-		}
+		]
 	},
 	error: function ( err ) {
 		assert.equal( err.message, 'nope' );
diff --git a/test/function/custom-path-resolver-plural/_config.js b/test/function/custom-path-resolver-plural/_config.js
index dd63a44..69a5c7c 100644
--- a/test/function/custom-path-resolver-plural/_config.js
+++ b/test/function/custom-path-resolver-plural/_config.js
@@ -4,18 +4,22 @@ var assert = require( 'assert' );
 module.exports = {
 	description: 'uses custom path resolvers (plural)',
 	options: {
-		resolveId: [
-			function ( importee ) {
-				if ( importee[0] === '@' )
-					return path.resolve( __dirname, 'globals-' + importee.slice( 1 ).toLowerCase() + '.js' );
+		plugins: [
+			{
+				resolveId: function ( importee ) {
+					if ( importee[0] === '@' )
+						return path.resolve( __dirname, 'globals-' + importee.slice( 1 ).toLowerCase() + '.js' );
+				},
+				load: function ( id ) {
+					if ( id === '<empty>' ) return '';
+				}
 			},
-			function ( importee ) {
-				if ( importee[0] === '!' ) return '<empty>';
+			{
+				resolveId: function ( importee ) {
+					if ( importee[0] === '!' ) return '<empty>';
+				}
 			}
-		],
-		load: function ( id ) {
-			if ( id === '<empty>' ) return '';
-		}
+		]
 	},
 	exports: function ( exports ) {
 		assert.strictEqual( exports.res, 0 );
diff --git a/test/function/custom-path-resolver-sync/_config.js b/test/function/custom-path-resolver-sync/_config.js
index ee993e1..4e0b5bf 100644
--- a/test/function/custom-path-resolver-sync/_config.js
+++ b/test/function/custom-path-resolver-sync/_config.js
@@ -4,12 +4,14 @@ var assert = require( 'assert' );
 module.exports = {
 	description: 'uses a custom path resolver (synchronous)',
 	options: {
-		resolveId: function ( importee, importer ) {
-			if ( path.normalize(importee) === path.resolve( __dirname, 'main.js' ) ) return importee;
-			if ( importee === 'foo' ) return path.resolve( __dirname, 'bar.js' );
+		plugins: [{
+			resolveId: function ( importee, importer ) {
+				if ( path.normalize(importee) === path.resolve( __dirname, 'main.js' ) ) return importee;
+				if ( importee === 'foo' ) return path.resolve( __dirname, 'bar.js' );
 
-			return false;
-		}
+				return false;
+			}
+		}]
 	},
 	exports: function ( exports ) {
 		assert.strictEqual( exports.path, require( 'path' ) );
diff --git a/test/function/does-not-hang-on-missing-module/_config.js b/test/function/does-not-hang-on-missing-module/_config.js
index afcdbcc..f5b0cfa 100644
--- a/test/function/does-not-hang-on-missing-module/_config.js
+++ b/test/function/does-not-hang-on-missing-module/_config.js
@@ -2,7 +2,12 @@ var assert = require( 'assert' );
 
 module.exports = {
 	description: 'does not hang on missing module (#53)',
-	error: function ( error ) {
-		assert.ok( /Could not find package unlessYouCreatedThisFileForSomeReason/.test( error.message ) );
+	options: {
+		onwarn: function ( msg ) {
+			assert.equal( "Treating 'unlessYouCreatedThisFileForSomeReason' as external dependency", msg );
+		}
+	},
+	runtimeError: function ( error ) {
+		assert.equal( "Cannot find module 'unlessYouCreatedThisFileForSomeReason'", error.message );
 	}
 };
diff --git a/test/function/import-from-external-subdirectory/_config.js b/test/function/import-from-external-subdirectory/_config.js
deleted file mode 100644
index 57a682c..0000000
--- a/test/function/import-from-external-subdirectory/_config.js
+++ /dev/null
@@ -1,4 +0,0 @@
-module.exports = {
-	description: 'default resolver imports from a subdirectory of an external module',
-	babel: true
-};
diff --git a/test/function/import-from-external-subdirectory/main.js b/test/function/import-from-external-subdirectory/main.js
deleted file mode 100644
index 966ed65..0000000
--- a/test/function/import-from-external-subdirectory/main.js
+++ /dev/null
@@ -1,5 +0,0 @@
-// this test is brittle, it relies on this dependency continuing
-// to be structured in a certain way
-import btoa from 'magic-string/src/utils/btoa';
-
-assert.equal( btoa( 'it works' ), new Buffer( 'it works' ).toString( 'base64' ) );
diff --git a/test/function/uses-supplied-ast/_config.js b/test/function/uses-supplied-ast/_config.js
index fff6bd6..3a35833 100644
--- a/test/function/uses-supplied-ast/_config.js
+++ b/test/function/uses-supplied-ast/_config.js
@@ -19,16 +19,18 @@ var modules = {
 module.exports = {
 	description: 'uses supplied AST',
 	options: {
-		resolveId: function ( importee, importer ) {
-			if ( !importer ) return 'main';
-			return importee;
-		},
-		load: function ( id ) {
-			if ( id === 'bar' ) {
-				throw new Error( 'loaded incorrect module' );
-			}
+		plugins: [{
+			resolveId: function ( importee, importer ) {
+				if ( !importer ) return 'main';
+				return importee;
+			},
+			load: function ( id ) {
+				if ( id === 'bar' ) {
+					throw new Error( 'loaded incorrect module' );
+				}
 
-			return modules[ id ];
-		}
+				return modules[ id ];
+			}
+		}]
 	}
 };