feat: add support for exports with patterns

Author: danielroe

src/core/build/index.ts

@@ -72,7 +72,8 @@ export const build = async (
   logRollupConfig(pkg, rollupConfig)
 
   await runInParallel(pkg.folderExports, folder => {
-    const { 1: distDir = folder } = folder.match(/^(.*[^*/])[*/]*$/) || []
+    const { 1: distDir = folder, 3: ext } =
+      folder.match(/^([^*]+[^*/])[*/]+(\.([a-z]+))?$/) || []
     const sourceFolder = pkg.resolveEntrypointFolder(distDir)
     if (!sourceFolder) return
 
@@ -84,6 +85,9 @@ export const build = async (
       srcDir,
       distDir: distDir.slice(2),
       rootDir: pkg.options.rootDir,
+      ext: ['mjs', 'ts', 'js'].includes(ext)
+        ? (ext as 'mjs' | 'ts' | 'js')
+        : undefined,
       ...pkg.options.mkdist,
     })
   })

src/core/package/index.ts

@@ -423,7 +423,9 @@ export class Package {
         `./${this.pkg.main}`,
         `./${this.pkg.module}`,
         `./${this.pkg.browser}`,
-      ].includes(item) && !/[./*]$/.test(item)
+      ].includes(item) &&
+      !item.endsWith('/') &&
+      !item.includes('*')
 
     if (!exports) return []
     if (typeof exports === 'string') return [exports].filter(filterExports)
@@ -435,7 +437,7 @@ export class Package {
   get folderExports(): string[] {
     const { exports } = this.pkg
 
-    const filterExports = (item: string) => /[a-z]\/\*$/.test(item)
+    const filterExports = (item: string) => /[a-z]\/\*(\.[a-z]*)?$/.test(item)
 
     if (!exports) return []
     if (typeof exports === 'string') return [exports].filter(filterExports)