Fix many lurking undefined errors

[mifi]

there was an assumption that assembly is required and is never undefined even though it is typed as optional and assigned to undefined in onError

[github-actions]

Diff output files

diff --git a/packages/@uppy/transloadit/lib/index.js b/packages/@uppy/transloadit/lib/index.js
index bff7087..58d2664 100644
--- a/packages/@uppy/transloadit/lib/index.js
+++ b/packages/@uppy/transloadit/lib/index.js
@@ -152,6 +152,7 @@ export default class Transloadit extends BasePlugin {
     Object.defineProperty(this, _onCancelAll, {
       writable: true,
       value: async () => {
+        if (!this.assembly) return;
         try {
           await _classPrivateFieldLooseBase(this, _cancelAssembly)[_cancelAssembly](this.assembly.status);
         } catch (err) {
@@ -223,7 +224,8 @@ export default class Transloadit extends BasePlugin {
           _classPrivateFieldLooseBase(this, _connectAssembly)[_connectAssembly](this.assembly);
         };
         const updateAssemblies = () => {
-          return this.assembly.update();
+          var _this$assembly;
+          return (_this$assembly = this.assembly) == null ? void 0 : _this$assembly.update();
         };
         this.restored = Promise.resolve().then(() => {
           restoreState();
@@ -245,9 +247,9 @@ export default class Transloadit extends BasePlugin {
         (_assemblyOptions$fiel = assemblyOptions.fields) != null ? _assemblyOptions$fiel : assemblyOptions.fields = {};
         validateParams(assemblyOptions.params);
         try {
-          var _this$assembly;
-          const assembly = (_this$assembly = this.assembly) != null
-            ? _this$assembly
+          var _this$assembly2;
+          const assembly = (_this$assembly2 = this.assembly) != null
+            ? _this$assembly2
             : await _classPrivateFieldLooseBase(this, _createAssembly)[_createAssembly](fileIDs, assemblyOptions);
           if (this.opts.importFromUploadURLs) {
             await _classPrivateFieldLooseBase(this, _reserveFiles)[_reserveFiles](assembly, fileIDs);
@@ -273,6 +275,7 @@ export default class Transloadit extends BasePlugin {
     Object.defineProperty(this, _afterUpload, {
       writable: true,
       value: (fileIDs, uploadID) => {
+        var _this$assembly3;
         const files = fileIDs.map(fileID => this.uppy.getFile(fileID));
         const filteredFileIDs = files.filter(file => !file.error).map(file => file.id);
         if (this.restored) {
@@ -280,15 +283,20 @@ export default class Transloadit extends BasePlugin {
             return _classPrivateFieldLooseBase(this, _afterUpload)[_afterUpload](filteredFileIDs, uploadID);
           });
         }
-        const assemblyID = this.assembly.status.assembly_id;
+        const assemblyID = (_this$assembly3 = this.assembly) == null ? void 0 : _this$assembly3.status.assembly_id;
         const closeSocketConnections = () => {
-          this.assembly.close();
+          var _this$assembly4;
+          (_this$assembly4 = this.assembly) == null || _this$assembly4.close();
         };
         if (!_classPrivateFieldLooseBase(this, _shouldWaitAfterUpload)[_shouldWaitAfterUpload]()) {
+          var _this$assembly5;
           closeSocketConnections();
-          this.uppy.addResultData(uploadID, {
-            transloadit: [this.assembly.status],
-          });
+          const status = (_this$assembly5 = this.assembly) == null ? void 0 : _this$assembly5.status;
+          if (status != null) {
+            this.uppy.addResultData(uploadID, {
+              transloadit: [status],
+            });
+          }
           return Promise.resolve();
         }
         if (!assemblyID) {
@@ -305,18 +313,22 @@ export default class Transloadit extends BasePlugin {
           });
         });
         return _classPrivateFieldLooseBase(this, _watcher)[_watcher].promise.then(() => {
+          var _this$assembly6;
           closeSocketConnections();
-          this.uppy.addResultData(uploadID, {
-            transloadit: [this.assembly.status],
-          });
+          const status = (_this$assembly6 = this.assembly) == null ? void 0 : _this$assembly6.status;
+          if (status != null) {
+            this.uppy.addResultData(uploadID, {
+              transloadit: [status],
+            });
+          }
         });
       },
     });
     Object.defineProperty(this, _closeAssemblyIfExists, {
       writable: true,
       value: () => {
-        var _this$assembly2;
-        (_this$assembly2 = this.assembly) == null || _this$assembly2.close();
+        var _this$assembly7;
+        (_this$assembly7 = this.assembly) == null || _this$assembly7.close();
       },
     });
     Object.defineProperty(this, _onError, {
@@ -414,7 +426,8 @@ export default class Transloadit extends BasePlugin {
     });
   }
   getAssembly() {
-    return this.assembly.status;
+    var _this$assembly8;
+    return (_this$assembly8 = this.assembly) == null ? void 0 : _this$assembly8.status;
   }
   getAssemblyFiles(assemblyID) {
     return this.uppy.getFiles().filter(file => {
@@ -632,10 +645,10 @@ function _onResult2(assemblyId, stepName, result) {
   });
   this.uppy.emit("transloadit:result", stepName, result, this.getAssembly());
 }
-function _onAssemblyFinished2(status) {
-  const url = status.assembly_ssl_url;
+function _onAssemblyFinished2(assembly) {
+  const url = assembly.status.assembly_ssl_url;
   this.client.getAssemblyStatus(url).then(finalStatus => {
-    this.assembly.status = finalStatus;
+    assembly.status = finalStatus;
     this.uppy.emit("transloadit:complete", finalStatus);
   });
 }
@@ -678,11 +691,11 @@ function _connectAssembly2(assembly) {
   }
   if (this.opts.waitForEncoding) {
     assembly.on("finished", () => {
-      _classPrivateFieldLooseBase(this, _onAssemblyFinished)[_onAssemblyFinished](assembly.status);
+      _classPrivateFieldLooseBase(this, _onAssemblyFinished)[_onAssemblyFinished](assembly);
     });
   } else if (this.opts.waitForMetadata) {
     assembly.on("metadata", () => {
-      _classPrivateFieldLooseBase(this, _onAssemblyFinished)[_onAssemblyFinished](assembly.status);
+      _classPrivateFieldLooseBase(this, _onAssemblyFinished)[_onAssemblyFinished](assembly);
     });
   }
   if (assembly.ok === "ASSEMBLY_COMPLETE") {