fix: work with jest (mikeal#14)

Jest [doesn't support package exports](jestjs/jest#9771),
nor does it support `browser` overrides out of the box (though it
[can be configured](https://jestjs.io/docs/configuration#resolver-string)).

This means it parses the stubbed files introduced in mikeal#13 as javascript,
so let's just require and export the file that the stub is stubbing.

This has the added bonus of also supporting old nodes that don't
understand package exports.

Fixes achingbrain/uint8arrays#21

Author: achingbrain

package.json

@@ -33,11 +33,12 @@
     "tempy": "^1.0.0"
   },
   "dependencies": {
-    "acorn": "^8.0.5",
     "@tgrajewski/rmtree": "^1.0.1",
+    "acorn": "^8.0.5",
+    "escodegen": "^2.0.0",
     "esm-ast-to-cjs": "^0.0.2",
-    "rollup-plugin-preserve-shebangs": "^0.2.0",
+    "file-url": "^4.0.0",
     "rollup": "^2.38.1",
-    "escodegen": "^2.0.0"
+    "rollup-plugin-preserve-shebangs": "^0.2.0"
   }
 }

src/package/index.js

@@ -4,7 +4,7 @@ import file from './file.js'
 import testFile from './testFile.js'
 import path from '../path-to-url.js'
 import { fileURLToPath } from 'url'
-import { join, dirname } from 'path'
+import { join, dirname, resolve, relative } from 'path'
 import rmtree from '@tgrajewski/rmtree'
 import preserveShebangs from 'rollup-plugin-preserve-shebangs'
 
@@ -163,9 +163,11 @@ class Package {
     await unlink(new URL(dist + '/cjs/_ipjsInput.js'))
   }
 
-  async stubFiles (dist, files) {
+  async stubFiles (dist, overrides) {
     await Promise.all(
-      files.map(async (file) => {
+      Object.keys(overrides).map(async (file) => {
+        const target = overrides[file]
+
         if (file === '.') {
           file = 'index.js'
         }
@@ -189,7 +191,17 @@ class Package {
           return
         }
 
-        await writeFile(new URL(dist + '/' + file), '')
+        const distPath = fileURLToPath(dist)
+        const stubUrl = new URL(dist + '/' + file)
+        const stubPath = fileURLToPath(stubUrl)
+        const targetPath = resolve(join(distPath, target))
+        let relativePath = relative(dirname(stubPath), targetPath)
+
+        if (!relativePath.startsWith('./')) {
+          relativePath = `./${relativePath}`
+        }
+
+        await writeFile(stubUrl, `module.exports = require('${relativePath}')\n`)
       })
     )
   }
@@ -241,7 +253,7 @@ class Package {
       json.exports = json.exports.import
       json.browser = json.browser.import
     }
-    await this.stubFiles(dist, Object.keys(json.browser))
+    await this.stubFiles(dist, json.browser)
     let files = Promise.all(pending)
     pending.push(writeFile(new URL(dist + '/package.json'), JSON.stringify(json, null, 2)))
     const typeModule = {

src/path-to-url.js

@@ -1,3 +1,5 @@
+import fileToUrl from 'file-url'
+
 // adapted from https://nodejs.org/api/path.html#path_path_resolve_paths
 const CHAR_FORWARD_SLASH = '/'
 const percentRegEx = /%/g
@@ -24,5 +26,8 @@ export default (filepath, cwd) => {
   if (resolved.includes('\r')) { resolved = resolved.replace(carriageReturnRegEx, '%0D') }
   if (resolved.includes('\t')) { resolved = resolved.replace(tabRegEx, '%09') }
   outURL.pathname = resolved
+
+  console.log('__resolved__', resolved)
+  console.log('__what__', fileToUrl(resolved))
   return outURL
 }

test/fixtures/pkg-kitchensink/output-main/index.js

@@ -0,0 +1 @@
+module.exports = require('./cjs/src/browser.js')

test/fixtures/pkg-kitchensink/output-main/secondary

@@ -0,0 +1 @@
+module.exports = require('./cjs/src/secondary.js')

test/fixtures/pkg-kitchensink/output-notests/index.js

@@ -0,0 +1 @@
+module.exports = require('./cjs/src/browser.js')

test/fixtures/pkg-kitchensink/output-notests/secondary

@@ -0,0 +1 @@
+module.exports = require('./cjs/src/secondary.js')

test/fixtures/pkg-kitchensink/output-tests/index.js

@@ -0,0 +1 @@
+module.exports = require('./cjs/src/browser.js')

test/fixtures/pkg-kitchensink/output-tests/secondary

@@ -0,0 +1 @@
+module.exports = require('./cjs/src/secondary.js')