fix: respect empty values for transform tasks without props

package.json

@@ -18,7 +18,7 @@
     "build": "gulp build",
     "build:main": "gulp typescript:main",
     "build:module": "gulp typescript:module",
-    "build:browser": "gulp rollup",
+    "build:browser": "gulp build:rollup",
     "lint": "tslint --project . src/**/*.ts",
     "prism:mock": "node test/prism.js",
     "prism:record": "node test/prism.js --record",

src/lib/api/transform.spec.ts

@@ -56,6 +56,7 @@ describe('transform', () => {
       polaroid: true,
       flip: false,
       flop: true,
+      compress: false,
     };
 
     const result = transform(url, testConfig);
@@ -231,4 +232,38 @@ describe('transform', () => {
       assert.equal(result, expected);
     });
   });
+
+  describe('cache', () => {
+    it('should construct valid parameters', () => {
+      const testConfig = {
+        cache: false,
+      };
+
+      const result = transform(url, testConfig);
+      const expected = `${cdnUrl}/cache=false/${url}`;
+      assert.equal(result, expected);
+
+      const testConfig2 = {
+        cache: {
+          expiry: 12345,
+        },
+      };
+
+      const result2 = transform(url, testConfig2);
+      const expected2 = `${cdnUrl}/cache=expiry:12345/${url}`;
+      assert.equal(result2, expected2);
+    });
+  });
+
+  describe('compress', () => {
+    it('should construct valid parameters', () => {
+      const testConfig = {
+        compress: true,
+      };
+
+      const result = transform(url, testConfig);
+      const expected = `${cdnUrl}/compress/${url}`;
+      assert.equal(result, expected);
+    });
+  });
 });

src/lib/api/transform.ts

@@ -867,12 +867,12 @@ const optionToString = (key: string, values: any): string => {
 
   // if we just want to enable feature
   if (typeof values === 'boolean') {
-    if (values === undefined) {
-      return '';
+    if (!values && key === 'cache') {
+      return `${key}=false`;
     }
 
     if (!values) {
-      return `${key}=false`;
+      return '';
     }
 
     return key;