feat: add support for 'internLoaderPath' in loader options

resolves #872

docs/configuration.md

@@ -420,7 +420,9 @@ environment (CommonJS in Node and <script> tag injection in the browser).
 
 To use one of Intern's pre-defined loader scripts, simply specify it's name. The
 loader script will expect the loader package to be installed in `node_modules`
-using NPM.
+using NPM. The loader file location can be customized with the `internLoaderPath`
+option, which although it is specified on the `options` object passed to the
+loader, it will be consumed by Intern and not passed to the loader config.
 
 ```json5
 {
@@ -430,6 +432,19 @@ using NPM.
 }
 ```
 
+Custom loader path with `internLoaderPath`:
+
+```json5
+{
+  browser: {
+    loader: 'dojo',
+    options: {
+      internLoaderPath: '../path/to/dojo/dojo.js'
+    }
+  }
+}
+```
+
 Additional options may be provided through the options parameter. These options
 are passed through to the registered loader script.
 

src/lib/common/config.ts

@@ -499,7 +499,16 @@ export interface BenchmarkConfig extends BenchmarkReporterOptions {
 
 export interface LoaderDescriptor {
   script: string;
-  options?: { [key: string]: any };
+  options?: {
+    /**
+     * An optional file path for the loader. If unspecified Intern will assume the loader's package is
+     * installed in `node_modules`. This property is prefixed with "intern" to distinguish it from
+     * other properties which will be passed to the loader. If present, Intern will read this property
+     * and then filter it out of the config passed to the loader.
+     */
+    internLoaderPath?: string;
+    [key: string]: any;
+  };
 }
 
 export interface EnvironmentSpec {

src/loaders/dojo.ts

@@ -5,21 +5,25 @@
  */
 intern.registerLoader(options => {
   const globalObj: any = typeof window !== 'undefined' ? window : global;
+  const {
+    internLoaderPath = 'node_modules/dojo/dojo.js',
+    ...loaderConfig
+  } = options;
 
-  options.baseUrl = options.baseUrl || intern.config.basePath;
-  if (!('async' in options)) {
-    options.async = true;
+  loaderConfig.baseUrl = loaderConfig.baseUrl || intern.config.basePath;
+  if (!('async' in loaderConfig)) {
+    loaderConfig.async = true;
   }
 
-  options.has = {
+  loaderConfig.has = {
     'dojo-timeout-api': true,
-    ...options.has
+    ...loaderConfig.has
   };
 
-  intern.log('Configuring Dojo loader with:', options);
-  globalObj.dojoConfig = options;
+  intern.log('Configuring Dojo loader with:', loaderConfig);
+  globalObj.dojoConfig = loaderConfig;
 
-  return intern.loadScript('node_modules/dojo/dojo.js').then(() => {
+  return intern.loadScript(internLoaderPath).then(() => {
     const require = globalObj.require;
     intern.log('Using Dojo loader');
 

src/loaders/dojo2.ts

@@ -7,13 +7,18 @@
  */
 intern.registerLoader(options => {
   const globalObj: any = typeof window !== 'undefined' ? window : global;
-  return intern.loadScript('node_modules/@dojo/loader/loader.js').then(() => {
+  const {
+    internLoaderPath = 'node_modules/@dojo/loader/loader.js',
+    ...loaderConfig
+  } = options;
+
+  return intern.loadScript(internLoaderPath).then(() => {
     const require: DojoLoader.RootRequire = globalObj.require;
     intern.log('Using Dojo 2 loader');
 
-    options.baseUrl = options.baseUrl || intern.config.basePath;
-    intern.log('Configuring loader with:', options);
-    require.config(options);
+    loaderConfig.baseUrl = loaderConfig.baseUrl || intern.config.basePath;
+    intern.log('Configuring loader with:', loaderConfig);
+    require.config(loaderConfig);
 
     return (modules: string[]) => {
       let handle: { remove(): void };

src/loaders/systemjs.ts

@@ -7,15 +7,18 @@
  */
 
 intern.registerLoader(options => {
-  options.baseURL = options.baseURL || intern.config.basePath;
   const globalObj: any = typeof window !== 'undefined' ? window : global;
+  const {
+    internLoaderPath = 'node_modules/systemjs/dist/system.src.js',
+    ...loaderConfig
+  } = options;
+
+  loaderConfig.baseURL = loaderConfig.baseURL || intern.config.basePath;
 
   if (intern.environment === 'browser') {
-    return intern
-      .loadScript('node_modules/systemjs/dist/system.src.js')
-      .then(() => {
-        return configAndLoad(SystemJS);
-      });
+    return intern.loadScript(internLoaderPath).then(() => {
+      return configAndLoad(SystemJS);
+    });
   } else {
     // Use globalObj to get to require to improve testability
     const SystemJS = (globalObj.require || require)('systemjs');
@@ -25,8 +28,8 @@ intern.registerLoader(options => {
   function configAndLoad(loader: typeof SystemJS) {
     intern.log('Using SystemJS loader');
 
-    intern.log('Configuring SystemJS with:', options);
-    loader.config(options);
+    intern.log('Configuring SystemJS with:', loaderConfig);
+    loader.config(loaderConfig);
 
     return (modules: string[]) => {
       intern.log('Loading modules with SystemJS:', modules);

tests/unit/loaders/dojo.ts

@@ -15,7 +15,7 @@ registerSuite('loaders/dojo', function() {
   const mockIntern = {
     config: { basePath: '/' },
     emit: spy(() => {}),
-    loadScript: spy(() => Promise.resolve()),
+    loadScript: spy((_path: string) => Promise.resolve()),
     registerLoader: spy((_init: LoaderInit) => {}),
     log: spy(() => {})
   };
@@ -65,8 +65,14 @@ registerSuite('loaders/dojo', function() {
     tests: {
       init() {
         const init = mockIntern.registerLoader.getCall(0).args[0];
+        const defaultLoaderPath = 'node_modules/dojo/dojo.js';
+
         return (init({}) as Promise<any>).then(() => {
           assert.equal(mockIntern.loadScript.callCount, 1);
+          assert.equal(
+            mockIntern.loadScript.getCall(0).args[0],
+            defaultLoaderPath
+          );
           assert.deepEqual(
             global.dojoConfig,
             {
@@ -112,6 +118,20 @@ registerSuite('loaders/dojo', function() {
             }
           );
         });
+      },
+
+      internLoaderPath() {
+        const init: LoaderInit = mockIntern.registerLoader.getCall(0).args[0];
+        const loaderOptions = {
+          internLoaderPath: 'foo/bar'
+        };
+
+        return Promise.resolve(init(loaderOptions)).then(() => {
+          assert.equal(
+            mockIntern.loadScript.lastCall.args[0],
+            loaderOptions.internLoaderPath
+          );
+        });
       }
     }
   };

tests/unit/loaders/dojo2.ts

@@ -15,7 +15,7 @@ registerSuite('loaders/dojo2', function() {
   const mockIntern = {
     config: { basePath: '/' },
     emit: spy(() => {}),
-    loadScript: spy(() => Promise.resolve()),
+    loadScript: spy((_path: string) => Promise.resolve()),
     registerLoader: spy((_init: LoaderInit) => {}),
     log: spy(() => {})
   };
@@ -67,8 +67,14 @@ registerSuite('loaders/dojo2', function() {
     tests: {
       init() {
         const init = mockIntern.registerLoader.getCall(0).args[0];
+        const defaultLoaderPath = 'node_modules/@dojo/loader/loader.js';
+
         return (init({}) as Promise<any>).then(() => {
           assert.equal(mockIntern.loadScript.callCount, 1);
+          assert.equal(
+            mockIntern.loadScript.getCall(0).args[0],
+            defaultLoaderPath
+          );
         });
       },
 
@@ -103,6 +109,20 @@ registerSuite('loaders/dojo2', function() {
             }
           );
         });
+      },
+
+      internLoaderPath() {
+        const init: LoaderInit = mockIntern.registerLoader.getCall(0).args[0];
+        const loaderOptions = {
+          internLoaderPath: 'foo/bar'
+        };
+
+        return Promise.resolve(init(loaderOptions)).then(() => {
+          assert.equal(
+            mockIntern.loadScript.lastCall.args[0],
+            loaderOptions.internLoaderPath
+          );
+        });
       }
     }
   };

tests/unit/loaders/systemjs.ts

@@ -17,7 +17,7 @@ registerSuite('loaders/systemjs', function() {
     environment: intern.environment,
     config: { basePath: '/' },
     emit: spy(() => {}),
-    loadScript: spy(() => Promise.resolve()),
+    loadScript: spy((_path: string) => Promise.resolve()),
     registerLoader: spy((_init: LoaderInit) => {}),
     log: spy(() => {})
   };
@@ -49,6 +49,7 @@ registerSuite('loaders/systemjs', function() {
       global.intern = mockIntern;
       global.require = fakeRequire;
       global.SystemJS = mockSystemJS;
+      mockIntern.environment = intern.environment;
       mockIntern.emit.resetHistory();
       mockIntern.loadScript.resetHistory();
       fakeRequire.resetHistory();
@@ -63,9 +64,15 @@ registerSuite('loaders/systemjs', function() {
     tests: {
       init() {
         const init = mockIntern.registerLoader.getCall(0).args[0];
+        const defaultLoaderPath = 'node_modules/systemjs/dist/system.src.js';
+
         return Promise.resolve(init({})).then(() => {
           if (intern.environment === 'browser') {
             assert.equal(mockIntern.loadScript.callCount, 1);
+            assert.equal(
+              mockIntern.loadScript.getCall(0).args[0],
+              defaultLoaderPath
+            );
           }
         });
       },
@@ -95,6 +102,24 @@ registerSuite('loaders/systemjs', function() {
             }
           );
         });
+      },
+
+      internLoaderPath() {
+        // the SystemJS loader only calls `loadScript` in the browser
+        mockIntern.environment = 'browser';
+
+        const init: LoaderInit = mockIntern.registerLoader.getCall(0).args[0];
+        const loaderOptions = {
+          internLoaderPath: 'foo/bar'
+        };
+
+        return Promise.resolve(init(loaderOptions)).then(() => {
+          assert.equal(mockIntern.loadScript.callCount, 1);
+          assert.equal(
+            mockIntern.loadScript.lastCall.args[0],
+            loaderOptions.internLoaderPath
+          );
+        });
       }
     }
   };