feat: add new option transformOutputPath

src/plugin.js

@@ -16,37 +16,55 @@ const defaultOptions = {
 const outputFileName = (filePath) => filePath
   .replace(/\.[^/.]+$/, '');
 
+/**
+ * Callback for transforming output file path
+ *
+ * @callback TransformOutputPathFn
+ * @param {string} output target file name
+ * @param {string} input source file name
+ */
+
 /**
  *  multiInput is a rollup plugin to use multiple entry point and preserve the directory
  *  structure in the dist folder
  *
  *  @param {?Object} options
  *  @param {?FastGlob.Options} options.glob the fast-glob configuration object
  *  @param {?string} options.relative the base path to remove in the dist folder
+ *  @param {?TransformOutputPathFn} options.transformOutputPath callback function to transform the destination file name before generation
  *  @return {Plugin} the rollup plugin config for enable support of multi-entry glob inputs
  * */
 export default ({
   glob: globOptions,
   relative = defaultOptions.relative,
+  transformOutputPath,
 } = defaultOptions) => ({
   pluginName,
   options(conf) {
     // flat to enable input to be a string or an array
     // separate globs inputs string from others to enable input to be a mixed array too
     const [globs, others] = partition([conf.input].flat(), isString);
     // get files from the globs strings and return as a Rollup entries Object
+
     const input = Object
       .assign(
         {},
         fromPairs(fastGlob
           .sync(globs, globOptions)
           .map((name) => {
-            const filePath = path.relative(relative, name);
+            let filePath = path.relative(relative, name);
             const isRelative = !filePath.startsWith('../');
             const relativeToRoot = () => path.relative('./', name);
-            return [outputFileName(isRelative
+
+            filePath = isRelative
               ? filePath
-              : relativeToRoot()), name];
+              : relativeToRoot();
+
+            if (transformOutputPath) {
+              filePath = transformOutputPath(filePath, name);
+            }
+
+            return [outputFileName(filePath), name];
           })),
         // add no globs input to the result
         ...others,

test/plugin.test.js

@@ -1,6 +1,7 @@
 import { rollup } from 'rollup';
 import importJson from '@rollup/plugin-json';
 import multiInput from '../src/plugin';
+import path from 'path';
 
 const expectedOutput = [
   'fixtures/input1.js',
@@ -78,4 +79,17 @@ describe('rollup-plugin-multi-input', () => {
       'test/fixtures/input2.js',
     ]);
   });
+  it('should resolve output to "dist" directory', async () => {
+    const outputFiles = await generateOutputFileNames({
+      input: ['test/fixtures/**/*.js'],
+      plugins: [multiInput({
+        transformOutputPath: (output, input) => `dest/${path.basename(output)}`
+      })],
+      external: ['fast-glob', 'path'],
+    });
+    expect(outputFiles).toEqual([
+      'dest/input1.js',
+      'dest/input2.js',
+    ]);
+  });
 });