add more tests

Author: Marc Neuhaus

fixtures/css/h2_styles.styl

@@ -0,0 +1,3 @@
+base = #f938ab
+h2
+  color: saturation(base, 5%);

test/WebpackConfig.js

@@ -519,6 +519,31 @@ describe('WebpackConfig object', () => {
         });
     });
 
+    describe('enableStylusLoader', () => {
+        it('Calling method sets it', () => {
+            const config = createConfig();
+            config.enableStylusLoader();
+
+            expect(config.useStylusLoader).to.be.true;
+        });
+
+        it('Calling with callback', () => {
+            const config = createConfig();
+            const callback = (stylusOptions) => {};
+            config.enableStylusLoader(callback);
+
+            expect(config.stylusLoaderOptionsCallback).to.equal(callback);
+        });
+
+        it('Calling with non-callback throws an error', () => {
+            const config = createConfig();
+
+            expect(() => {
+                config.enableStylusLoader('FOO');
+            }).to.throw('must be a callback function');
+        });
+    });
+
     describe('enablePreactPreset', () => {
         it('Without preact-compat', () => {
             const config = createConfig();

test/config-generator.js

@@ -307,6 +307,32 @@ describe('The config-generator function', () => {
         });
     });
 
+    describe('enableStylusLoader() adds the stylus-loader', () => {
+        it('without enableStylusLoader()', () => {
+            const config = createConfig();
+            config.outputPath = '/tmp/output/public-path';
+            config.publicPath = '/public-path';
+            config.addEntry('main', './main');
+            // do not enable the stylus loader
+
+            const actualConfig = configGenerator(config);
+
+            expect(JSON.stringify(actualConfig.module.rules)).to.not.contain('stylus-loader');
+        });
+
+        it('enableStylusLoader()', () => {
+            const config = createConfig();
+            config.outputPath = '/tmp/output/public-path';
+            config.publicPath = '/public-path';
+            config.addEntry('main', './main');
+            config.enableStylusLoader();
+
+            const actualConfig = configGenerator(config);
+
+            expect(JSON.stringify(actualConfig.module.rules)).to.contain('stylus-loader');
+        });
+    });
+
     describe('addLoader() adds a custom loader', () => {
         it('addLoader()', () => {
             const config = createConfig();

test/functional.js

@@ -657,6 +657,24 @@ module.exports = {
             });
         });
 
+        it('stylus processes when enabled', (done) => {
+            const config = createWebpackConfig('www/build', 'dev');
+            config.setPublicPath('/build');
+            config.addStyleEntry('styles', ['./css/h2_styles.styl']);
+            config.enableStylusLoader();
+
+            testSetup.runWebpack(config, (webpackAssert) => {
+                // check that stylus did its work!
+                webpackAssert.assertOutputFileContains(
+                    'styles.css',
+                    // stylus logic inside will resolve to tis
+                    'color: #9e9399;'
+                );
+
+                done();
+            });
+        });
+
         it('Babel is executed on .js files', (done) => {
             const config = createWebpackConfig('www/build', 'dev');
             config.setPublicPath('/build');