Strict nulls for everything except logconsole

buildutils/src/utils.ts

@@ -341,18 +341,15 @@ export function ensureUnixPathSep(source: string) {
 /**
  * Get the last portion of a path, without its extension (if any).
  *
- * @param path - The file path.
+ * @param pathArg - The file path.
  *
  * @returns the last part of the path, sans extension.
  */
-export function stem(path: string): string {
+export function stem(pathArg: string): string {
   return path
-    .split('\\')
-    .pop()
-    .split('/')
-    .pop()
+    .basename(pathArg)
     .split('.')
-    .shift();
+    .shift()!;
 }
 
 /**

packages/apputils/src/clipboard.ts

@@ -70,8 +70,8 @@ export namespace Clipboard {
 
     // Save the current selection.
     let savedRanges: any[] = [];
-    for (let i = 0, len = sel.rangeCount; i < len; ++i) {
-      savedRanges[i] = sel.getRangeAt(i).cloneRange();
+    for (let i = 0, len = sel?.rangeCount || 0; i < len; ++i) {
+      savedRanges[i] = sel!.getRangeAt(i).cloneRange();
     }
 
     // Select the node content.

packages/apputils/src/printing.ts

@@ -90,10 +90,11 @@ export namespace Printing {
       await resolveWhenLoaded(iframe);
     } else {
       iframe.src = 'about:blank';
+      await resolveWhenLoaded(iframe);
       setIFrameNode(iframe, textOrEl as HTMLElement);
     }
     const printed = resolveAfterEvent();
-    launchPrint(iframe.contentWindow);
+    launchPrint(iframe.contentWindow!);
     // Once the print dialog has been dismissed, we regain event handling,
     // and it should be safe to discard the hidden iframe.
     await printed;

packages/completer/src/model.ts

@@ -101,7 +101,7 @@ export class CompleterModel implements Completer.IModel {
       return;
     }
 
-    const { start, end } = this._cursor;
+    const { start, end } = cursor;
     // Clip the front of the current line.
     let query = current.text.substring(start);
     // Clip the back of the current line by calculating the end of the original.

packages/coreutils/src/settingregistry.ts

@@ -312,8 +312,9 @@ export class SettingRegistry implements ISettingRegistry {
       const { composite, user } = plugins[plugin].data;
 
       return {
-        composite: key in composite ? copy(composite[key]) : undefined,
-        user: key in user ? copy(user[key]) : undefined
+        composite:
+          composite[key] !== undefined ? copy(composite[key]!) : undefined,
+        user: user[key] !== undefined ? copy(user[key]!) : undefined
       };
     }
 
@@ -785,8 +786,9 @@ export class Settings implements ISettingRegistry.ISettings {
     const { composite, user } = this;
 
     return {
-      composite: key in composite ? copy(composite[key]) : undefined,
-      user: key in user ? copy(user[key]) : undefined
+      composite:
+        composite[key] !== undefined ? copy(composite[key]!) : undefined,
+      user: user[key] !== undefined ? copy(user[key]!) : undefined
     };
   }
 

packages/csvviewer/src/parse.ts

@@ -401,9 +401,11 @@ export function parseDSV(options: IParser.IOptions): IParser.IResults {
       case NEW_ROW:
         nrows++;
 
-        // If we just parsed the first row and the ncols is undefined, set it to
-        // the number of columns we found in the first row.
-        if (nrows === 1 && ncols === undefined) {
+        // If ncols is undefined, set it to the number of columns in this row (first row implied).
+        if (ncols === undefined) {
+          if (nrows !== 1) {
+            throw new Error('Error parsing default number of columns');
+          }
           ncols = col;
         }
 

packages/docmanager-extension/src/index.ts

@@ -468,6 +468,13 @@ function addCommands(
       }
       const context = docManager.contextForWidget(shell.currentWidget!);
       const type = fileType(shell.currentWidget!, docManager);
+      if (!context) {
+        return showDialog({
+          title: 'Cannot Reload',
+          body: 'No context found for current widget!',
+          buttons: [Dialog.okButton()]
+        });
+      }
       return showDialog({
         title: `Reload ${type} from Disk`,
         body: `Are you sure you want to reload
@@ -492,6 +499,13 @@ function addCommands(
         return;
       }
       const context = docManager.contextForWidget(shell.currentWidget!);
+      if (!context) {
+        return showDialog({
+          title: 'Cannot Revert',
+          body: 'No context found for current widget!',
+          buttons: [Dialog.okButton()]
+        });
+      }
       return context.listCheckpoints().then(checkpoints => {
         if (checkpoints.length < 1) {
           return;
@@ -531,6 +545,13 @@ function addCommands(
       // Checks that shell.currentWidget is valid:
       if (isEnabled()) {
         let context = docManager.contextForWidget(shell.currentWidget!);
+        if (!context) {
+          return showDialog({
+            title: 'Cannot Save',
+            body: 'No context found for current widget!',
+            buttons: [Dialog.okButton()]
+          });
+        }
         if (context.model.readOnly) {
           return showDialog({
             title: 'Cannot Save',
@@ -583,6 +604,13 @@ function addCommands(
       // Checks that shell.currentWidget is valid:
       if (isEnabled()) {
         let context = docManager.contextForWidget(shell.currentWidget!);
+        if (!context) {
+          return showDialog({
+            title: 'Cannot Save',
+            body: 'No context found for current widget!',
+            buttons: [Dialog.okButton()]
+          });
+        }
         return context.saveAs();
       }
     }
@@ -596,6 +624,13 @@ function addCommands(
       // Checks that shell.currentWidget is valid:
       if (isEnabled()) {
         let context = docManager.contextForWidget(shell.currentWidget!);
+        if (!context) {
+          return showDialog({
+            title: 'Cannot Download',
+            body: 'No context found for current widget!',
+            buttons: [Dialog.okButton()]
+          });
+        }
         return context.download();
       }
     }

packages/docmanager/src/widgetmanager.ts

@@ -252,7 +252,7 @@ export class DocumentWidgetManager implements IDisposable {
    *
    * @param widget - The target widget.
    */
-  protected setCaption(widget: Widget): Promise<void> {
+  protected async setCaption(widget: Widget): Promise<void> {
     let context = Private.contextProperty.get(widget);
     if (!context) {
       return;

packages/documentsearch/src/providers/codemirrorsearchprovider.ts

@@ -412,7 +412,7 @@ export class CodeMirrorSearchProvider
 
           // if the last thing on the line was a match, make sure we still
           // emit the changed signal so the display can pick up the updates
-          if (stream.eol) {
+          if (stream.eol()) {
             this._changed.emit(undefined);
           }
           return 'searching';

packages/logconsole-extension/src/index.tsx

@@ -270,7 +270,7 @@ function activateLogConsole(
     } else {
       source = null;
     }
-    if (logConsoleWidget) {
+    if (logConsolePanel) {
       logConsolePanel.source = source;
     }
     status.model.source = source;

packages/logconsole-extension/src/status.tsx

@@ -32,10 +32,15 @@ function LogConsoleStatusComponent(
     title = `${props.newMessages} new messages, `;
   }
   title += `${props.logEntries} log entries for ${props.source}`;
+  // inline conditional doesn't seem to work with strict TS currently...
+  let cond: JSX.Element = (false as unknown) as JSX.Element;
+  if (props.newMessages > 0) {
+    cond = <TextItem source={props.newMessages} />;
+  }
   return (
     <GroupItem spacing={0} onClick={props.handleClick} title={title}>
       <DefaultIconReact name={'list'} top={'2px'} kind={'statusBar'} />
-      {props.newMessages > 0 && <TextItem source={props.newMessages} />}
+      {cond}
     </GroupItem>
   );
 }

packages/logconsole/src/widget.ts

@@ -355,7 +355,11 @@ export class LogConsolePanel extends StackedPanel {
         const viewId = `source:${sender.source}`;
         const outputArea = this._outputAreas.get(viewId);
         if (outputArea) {
-          outputArea.rendermime = change.newValue;
+          if (change.newValue) {
+            outputArea.rendermime = change.newValue;
+          } else {
+            outputArea.dispose();
+          }
         }
       }, this);
 

packages/notebook/src/actions.tsx

@@ -1757,7 +1757,7 @@ namespace Private {
 
       if (notebook.isSelectedOrActive(child) && deletable) {
         toDelete.push(index);
-        notebook.model.deletedCells.push(child.model.id);
+        model.deletedCells.push(child.model.id);
       }
     });
 

packages/notebook/src/model.ts

@@ -182,7 +182,7 @@ export class NotebookModel extends DocumentModel implements INotebookModel {
    */
   toJSON(): nbformat.INotebookContent {
     let cells: nbformat.ICell[] = [];
-    for (let i = 0; i < this.cells.length; i++) {
+    for (let i = 0; i < (this.cells?.length || 0); i++) {
       let cell = this.cells.get(i);
       cells.push(cell.toJSON());
     }

packages/notebook/src/notebooktools.ts

@@ -685,7 +685,7 @@ export namespace NotebookTools {
         this._validCellTypes.length &&
         this._validCellTypes.indexOf(cellType) === -1
       ) {
-        select.value = undefined;
+        select.value = '';
         select.disabled = true;
         return;
       }

packages/terminal-extension/src/index.ts

@@ -336,6 +336,7 @@ export function addCommands(
         Terminal = (await Private.ensureWidget()).Terminal;
       } catch (err) {
         Private.showErrorMessage(err);
+        return;
       }
 
       const name = args['name'] as string;
@@ -401,7 +402,7 @@ export function addCommands(
     label: 'Increase Terminal Font Size',
     execute: async () => {
       let { fontSize } = options;
-      if (fontSize < 72) {
+      if (fontSize && fontSize < 72) {
         try {
           await settingRegistry.set(plugin.id, 'fontSize', fontSize + 1);
         } catch (err) {
@@ -415,7 +416,7 @@ export function addCommands(
     label: 'Decrease Terminal Font Size',
     execute: async () => {
       let { fontSize } = options;
-      if (fontSize > 9) {
+      if (fontSize && fontSize > 9) {
         try {
           await settingRegistry.set(plugin.id, 'fontSize', fontSize - 1);
         } catch (err) {

tests/test-cells/src/widget.spec.ts

@@ -357,10 +357,10 @@ describe('cells/widget', () => {
       it('should not throw an error (full test in input area)', () => {
         const widget = new Cell({ model, contentFactory }).initializeState();
         expect(() => {
-          widget.setPrompt(void 0);
+          widget.setPrompt(void 0 as any);
         }).not.toThrow();
         expect(() => {
-          widget.setPrompt(null);
+          widget.setPrompt(null as any);
         }).not.toThrow();
         expect(() => {
           widget.setPrompt('');

tests/test-csvviewer/src/widget.spec.ts

@@ -113,7 +113,7 @@ describe('csvviewer/widget', () => {
       searchService.find(query);
       expect(fakeRenderCell(0, 1)).to.equal('currentMatch');
       expect(fakeRenderCell(1, 1)).to.equal('anotherMatch');
-      expect(fakeRenderCell(0, 0)).to.equal(undefined);
+      expect(fakeRenderCell(0, 0)).to.equal('');
 
       // search again, the current match "moves" to be (1,1)
       searchService.find(query);