meta: disable ESM to CJS transform in dist files (#3773)

* meta: disable ESM to CJS transorm in dist files

This commit removes all the hacks that needed to happen in order to ship
working CJS code. Onwards, we plan to distribute Uppy packages as ESM.

* No mocking with Jest and ESM

__mocks__/nanoid/non-secure.js

@@ -1 +0,0 @@
-module.exports = { nanoid: () => 'cjd09qwxb000dlql4tp4doz8h' }

bin/build-lib.js

@@ -21,13 +21,6 @@ const META_FILES = [
   'bin/build-lib.js',
 ]
 
-// Rollup uses get-form-data's ES modules build, and rollup-plugin-commonjs automatically resolves `.default`.
-// So, if we are being built using rollup, this require() won't have a `.default` property.
-const esPackagesThatNeedSpecialTreatmentForRollupInterop = [
-  'get-form-data',
-  'cropperjs',
-]
-
 function lastModified (file, createParentDir = false) {
   return stat(file).then((s) => s.mtime, async (err) => {
     if (err.code === 'ENOENT') {
@@ -55,29 +48,18 @@ async function isTypeModule (file) {
     // in case it hasn't been done before.
     await mkdir(path.join(packageFolder, 'lib'), { recursive: true })
   }
-  if (typeModule) {
-    await writeFile(path.join(packageFolder, 'lib', 'package.json'), '{"type":"commonjs"}')
-  }
   moduleTypeCache.set(packageFolder, typeModule)
   versionCache.set(packageFolder, version)
   return typeModule
 }
 
 // eslint-disable-next-line no-shadow
-function ExportAllDeclaration (path) {
+function transformJSXImportsToJS (path) {
   const { value } = path.node.source
   if (value.endsWith('.jsx') && (value.startsWith('./') || value.startsWith('../'))) {
     // Rewrite .jsx imports to .js:
     path.node.source.value = value.slice(0, -1) // eslint-disable-line no-param-reassign
   }
-
-  path.replaceWith(
-    t.assignmentExpression(
-      '=',
-      t.memberExpression(t.identifier('module'), t.identifier('exports')),
-      t.callExpression(t.identifier('require'), [path.node.source]),
-    ),
-  )
 }
 
 async function buildLib () {
@@ -104,19 +86,12 @@ async function buildLib () {
       }
     }
 
-    let idCounter = 0 // counter to ensure uniqueness of identifiers created by the build script.
-    const plugins = await isTypeModule(file) ? [['@babel/plugin-transform-modules-commonjs', {
-      importInterop: 'none',
-    }], {
+    const plugins = await isTypeModule(file) ? [{
       visitor: {
         // eslint-disable-next-line no-shadow
         ImportDeclaration (path) {
-          let { value } = path.node.source
-          if (value.endsWith('.jsx') && (value.startsWith('./') || value.startsWith('../'))) {
-            // Rewrite .jsx imports to .js:
-            value = path.node.source.value = value.slice(0, -1) // eslint-disable-line no-param-reassign,no-multi-assign
-          }
-          if (PACKAGE_JSON_IMPORT.test(value)
+          transformJSXImportsToJS(path)
+          if (PACKAGE_JSON_IMPORT.test(path.node.source.value)
               && path.node.specifiers.length === 1
               && path.node.specifiers[0].type === 'ImportDefaultSpecifier') {
             // Vendor-in version number from package.json files:
@@ -130,124 +105,14 @@ async function buildLib () {
                   ]))]),
               )
             }
-          } else if (path.node.specifiers[0].type === 'ImportDefaultSpecifier') {
-            const [{ local }, ...otherSpecifiers] = path.node.specifiers
-            if (otherSpecifiers.length === 1 && otherSpecifiers[0].type === 'ImportNamespaceSpecifier') {
-              // import defaultVal, * as namespaceImport from '@uppy/package'
-              // is transformed into:
-              // const defaultVal = require('@uppy/package'); const namespaceImport = defaultVal
-              path.insertAfter(
-                t.variableDeclaration('const', [
-                  t.variableDeclarator(
-                    otherSpecifiers[0].local,
-                    local,
-                  ),
-                ]),
-              )
-            } else if (otherSpecifiers.length !== 0) {
-              // import defaultVal, { exportedVal as importedName, other } from '@uppy/package'
-              // is transformed into:
-              // const defaultVal = require('@uppy/package'); const { exportedVal: importedName, other } = defaultVal
-              path.insertAfter(t.variableDeclaration('const', [t.variableDeclarator(
-                t.objectPattern(
-                  otherSpecifiers.map(specifier => t.objectProperty(
-                    t.identifier(specifier.imported.name),
-                    specifier.local,
-                  )),
-                ),
-                local,
-              )]))
-            }
-
-            let requireCall = t.callExpression(t.identifier('require'), [
-              t.stringLiteral(value),
-            ])
-            if (esPackagesThatNeedSpecialTreatmentForRollupInterop.includes(value)) {
-              requireCall = t.logicalExpression('||', t.memberExpression(requireCall, t.identifier('default')), requireCall)
-            }
-            path.replaceWith(
-              t.variableDeclaration('const', [
-                t.variableDeclarator(
-                  local,
-                  requireCall,
-                ),
-              ]),
-            )
           }
         },
-        ExportAllDeclaration,
-        // eslint-disable-next-line no-shadow,consistent-return
-        ExportNamedDeclaration (path) {
-          if (path.node.source != null) {
-            if (path.node.specifiers.length === 1
-                && path.node.specifiers[0].local.name === 'default'
-                && path.node.specifiers[0].exported.name === 'default') return ExportAllDeclaration(path)
 
-            if (path.node.specifiers.some(spec => spec.exported.name === 'default')) {
-              throw new Error('unsupported mix of named and default re-exports')
-            }
-
-            let { value } = path.node.source
-            if (value.endsWith('.jsx') && (value.startsWith('./') || value.startsWith('../'))) {
-              // Rewrite .jsx imports to .js:
-              value = path.node.source.value = value.slice(0, -1) // eslint-disable-line no-param-reassign,no-multi-assign
-            }
-
-            // If there are no default export/import involved, Babel can handle it with no problem.
-            if (path.node.specifiers.every(spec => spec.local.name !== 'default' && spec.exported.name !== 'default')) return undefined
-
-            let requireCall = t.callExpression(t.identifier('require'), [
-              t.stringLiteral(value),
-            ])
-            if (esPackagesThatNeedSpecialTreatmentForRollupInterop.includes(value)) {
-              requireCall = t.logicalExpression('||', t.memberExpression(requireCall, t.identifier('default')), requireCall)
-            }
-
-            const requireCallIdentifier = t.identifier(`_${idCounter++}`)
-            const namedExportIdentifiers = path.node.specifiers
-              .filter(spec => spec.local.name !== 'default')
-              .map(spec => [
-                t.identifier(requireCallIdentifier.name + spec.local.name),
-                t.memberExpression(requireCallIdentifier, spec.local),
-                spec,
-              ])
-            path.insertBefore(
-              t.variableDeclaration('const', [
-                t.variableDeclarator(
-                  requireCallIdentifier,
-                  requireCall,
-                ),
-                ...namedExportIdentifiers.map(([id, propertyAccessor]) => t.variableDeclarator(id, propertyAccessor)),
-              ]),
-            )
-            path.replaceWith(
-              t.exportNamedDeclaration(null, path.node.specifiers.map(spec => t.exportSpecifier(
-                spec.local.name === 'default' ? requireCallIdentifier : namedExportIdentifiers.find(([,, s]) => s === spec)[0],
-                spec.exported,
-              ))),
-            )
-          }
-        },
+        ExportAllDeclaration: transformJSXImportsToJS,
         // eslint-disable-next-line no-shadow
-        ExportDefaultDeclaration (path) {
-          const moduleExports =  t.memberExpression(t.identifier('module'), t.identifier('exports'))
-          if (!t.isDeclaration(path.node.declaration)) {
-            path.replaceWith(
-              t.assignmentExpression('=', moduleExports, path.node.declaration),
-            )
-          } else if (path.node.declaration.id != null) {
-            const { id } = path.node.declaration
-            path.insertBefore(path.node.declaration)
-            path.replaceWith(
-              t.assignmentExpression('=', moduleExports, id),
-            )
-          } else {
-            const id = t.identifier('_default')
-            path.node.declaration.id = id // eslint-disable-line no-param-reassign
-            path.insertBefore(path.node.declaration)
-            path.replaceWith(
-              t.assignmentExpression('=', moduleExports, id),
-            )
+        ExportNamedDeclaration (path) {
+          if (path.node.source != null) {
+            transformJSXImportsToJS(path)
           }
         },
       },

packages/@uppy/core/src/Uppy.test.js

@@ -896,7 +896,12 @@ describe('src/Core', () => {
       core.addFile({ source: 'jest', name: 'bar.jpg', type: 'image/jpeg', data: new Uint8Array() })
       core.addFile({ source: 'file3', name: 'file3.jpg', type: 'image/jpeg', data: new Uint8Array() })
 
-      return expect(core.upload()).resolves.toMatchSnapshot()
+      // uploadID is random, we don't want randomness in the snapshot
+      const validateNanoID = r => (
+        typeof r.uploadID === 'string' && r.uploadID.length === 21 ? ({ ...r, uploadID: 'cjd09qwxb000dlql4tp4doz8h' }) : r
+      )
+
+      return expect(core.upload().then(validateNanoID)).resolves.toMatchSnapshot()
     })
 
     it('should not upload if onBeforeUpload returned false', () => {