fix(convertTransform): do not add redundant space between functions (#1802)

The space is optional between transform functions in the `transform`
attribute and similar properties. This just omits the space as a
micro-optimization.

This does not add new tests is the scenario is covered adequately in
existing tests.

Also refactors js2transform to avoid concatenating in a loop.

Author: SethFalco

lib/svgo.test.js

@@ -395,14 +395,14 @@ test('encode as datauri', () => {
     plugins: ['convertTransform'],
   });
   expect(dataSinglePass).toMatchInlineSnapshot(
-    `"data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%3E%3Cg%20transform%3D%22scale(2)%20rotate(-45%20130.898%20-126.14)%22%2F%3E%3C%2Fsvg%3E"`
+    `"data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%3E%3Cg%20transform%3D%22scale(2)rotate(-45%20130.898%20-126.14)%22%2F%3E%3C%2Fsvg%3E"`
   );
   const { data: dataMultiPass } = optimize(input, {
     multipass: true,
     datauri: 'enc',
     plugins: ['convertTransform'],
   });
   expect(dataMultiPass).toMatchInlineSnapshot(
-    `"data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%3E%3Cg%20transform%3D%22rotate(-45%20261.796%20-252.28)%20scale(2)%22%2F%3E%3C%2Fsvg%3E"`
+    `"data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%3E%3Cg%20transform%3D%22rotate(-45%20261.796%20-252.28)scale(2)%22%2F%3E%3C%2Fsvg%3E"`
   );
 });

plugins/convertTransform.js

@@ -335,18 +335,12 @@ const removeUseless = (transforms) => {
  * @type {(transformJS: Array<TransformItem>, params: TransformParams) => string}
  */
 const js2transform = (transformJS, params) => {
-  var transformString = '';
-
-  // collect output value string
-  transformJS.forEach((transform) => {
-    roundTransform(transform, params);
-    transformString +=
-      (transformString && ' ') +
-      transform.name +
-      '(' +
-      cleanupOutData(transform.data, params) +
-      ')';
-  });
+  const transformString = transformJS
+    .map((transform) => {
+      roundTransform(transform, params);
+      return `${transform.name}(${cleanupOutData(transform.data, params)})`;
+    })
+    .join('');
 
   return transformString;
 };