feat: option to suppress value export (#673)

Fixes #672

Author: lunsdorf

packages/processor/README.md

@@ -224,6 +224,18 @@ new Processor({
 */
 ```
 
+### `exportValues`
+
+Enable exporting `@value` identifiers.
+
+**Default**: `true`
+
+```js
+new Processor({
+    exportValues : false
+});
+```
+
 ## Properties
 
 ### `.files`

packages/processor/processor.js

@@ -37,13 +37,14 @@ class Processor {
         const options = Object.assign(
             Object.create(null),
             {
-                cwd       : process.cwd(),
-                map       : false,
-                rewrite   : true,
-                verbose   : false,
-                resolvers : [],
-                postcss   : {},
-                dupewarn  : true,
+                cwd          : process.cwd(),
+                dupewarn     : true,
+                exportValues : true,
+                map          : false,
+                postcss      : {},
+                resolvers    : [],
+                rewrite      : true,
+                verbose      : false,
             },
             opts
         );
@@ -379,8 +380,11 @@ class Processor {
 
             file.exports = Object.assign(
                 Object.create(null),
-                // export @value entries
-                mapValues(file.values, ({ value }) => value),
+
+                // optionally export @value entries
+                this._options.exportValues ?
+                    mapValues(file.values, ({ value }) => value) :
+                    null,
 
                 // export classes
                 message(result, "classes"),

packages/processor/test/__snapshots__/options.test.js.snap

@@ -8,6 +8,23 @@ Object {
 }
 `;
 
+exports[`/processor.js options exportValues should not export @values by default 1`] = `
+Object {
+  "a": "#F00",
+  "b": Array [
+    "mc61ce7a4a_b",
+  ],
+}
+`;
+
+exports[`/processor.js options exportValues should not export @values when exportValues is false 1`] = `
+Object {
+  "b": Array [
+    "mc8df92ddf_b",
+  ],
+}
+`;
+
 exports[`/processor.js options lifecycle options after should run async postcss plugins 1`] = `
 "/* packages/processor/test/specimens/relative.css */
 .wooga {

packages/processor/test/options.test.js

@@ -146,6 +146,38 @@ describe("/processor.js", () => {
             });
         });
 
+        describe("exportValues", () => {
+            it("should export @values by default", async () => {
+                const processor = new Processor({});
+
+                const { exports } = await processor.string(
+                    "./exportValues.css",
+                    dedent(`
+                        @value a: #F00;
+                        .b {}
+                    `)
+                );
+
+                expect(exports).toMatchSnapshot();
+            });
+
+            it("should not export @values when exportValues is false", async () => {
+                const processor = new Processor({
+                    exportValues : false,
+                });
+
+                const { exports } = await processor.string(
+                    "./exportGlobals.css",
+                    dedent(`
+                        @value a: #F00;
+                        .b {}
+                    `)
+                );
+
+                expect(exports).toMatchSnapshot();
+            });
+        });
+
         describe("rewrite", () => {
             it("should rewrite url() references by default", async () => {
                 const processor = new Processor();