Fix cells being erased when saving and then changing focus to another… (#8482)

* Fix cells being erased when saving and then changing focus to another cell

* Make sure to use the source even if it's empty

Author: rchiodo

news/2 Fixes/8399.md

@@ -0,0 +1 @@
+Fix cells being erased when saving and then changing focus to another cell.

src/datascience-ui/interactive-common/mainStateController.ts

@@ -339,26 +339,21 @@ export class MainStateController implements IMessageHandler {
         this.clearAllSilent();
     }
 
-    public updateCellSource = (cellId: string) => {
-        const models = monacoEditor.editor.getModels();
-        const cvm = this.findCell(cellId);
-        if (cvm) {
-            const modelId = this.getMonacoId(cvm.cell.id);
-            if (modelId) {
-                const model = models.find(m => m.id === modelId);
-                if (model) {
-                    cvm.cell.data.source = cvm.inputBlockText = model.getValue().replace(/\r/g, '');
-                }
-            }
-        }
-    }
-
     public save = () => {
         // We have to take the current value of each cell to make sure we have the correct text.
-        this.pendingState.cellVMs.forEach(c => this.updateCellSource(c.cell.id));
+        const newVMs = [...this.pendingState.cellVMs];
+        for (let i = 0; i < newVMs.length; i += 1) {
+            const text = this.getMonacoEditorContents(newVMs[i].cell.id);
+            if (text !== undefined) {
+                newVMs[i] = { ...newVMs[i], inputBlockText: text, cell: { ...newVMs[i].cell, data: { ...newVMs[i].cell.data, source: text } } };
+            }
+        }
+        this.setState({
+            cellVMs: newVMs
+        });
 
         // Then send the save with the new state.
-        this.sendMessage(InteractiveWindowMessages.SaveAll, { cells: this.getNonEditCellVMs().map(cvm => cvm.cell) });
+        this.sendMessage(InteractiveWindowMessages.SaveAll, { cells: newVMs.map(cvm => cvm.cell) });
     }
 
     public showPlot = (imageHtml: string) => {
@@ -764,6 +759,20 @@ export class MainStateController implements IMessageHandler {
         return this.pendingState;
     }
 
+    public getMonacoEditorContents(cellId: string): string | undefined {
+        const index = this.findCellIndex(cellId);
+        if (index >= 0) {
+            // Get the model for the monaco editor
+            const monacoId = this.getMonacoId(cellId);
+            if (monacoId) {
+                const model = monacoEditor.editor.getModels().find(m => m.id === monacoId);
+                if (model) {
+                    return model.getValue().replace(/\r/g, '');
+                }
+            }
+        }
+    }
+
     // Adjust the visibility or collapsed state of a cell
     protected alterCellVM(cellVM: ICellViewModel, visible: boolean, expanded: boolean): ICellViewModel {
         if (cellVM.cell.data.cell_type === 'code') {
@@ -811,20 +820,6 @@ export class MainStateController implements IMessageHandler {
         return cellVM;
     }
 
-    protected getMonacoEditorContents(cellId: string): string | undefined {
-        const index = this.findCellIndex(cellId);
-        if (index >= 0) {
-            // Get the model for the monaco editor
-            const monacoId = this.getMonacoId(cellId);
-            if (monacoId) {
-                const model = monacoEditor.editor.getModels().find(m => m.id === monacoId);
-                if (model) {
-                    return model.getValue().replace(/\r/g, '');
-                }
-            }
-        }
-    }
-
     protected onCodeLostFocus(_cellId: string) {
         // Default is do nothing.
     }

src/datascience-ui/native-editor/nativeCell.tsx

@@ -482,7 +482,7 @@ export class NativeCell extends React.Component<INativeCellProps> {
         let content: string | undefined ;
 
         // If inside editor, submit this code
-        if (possibleContents) {
+        if (possibleContents !== undefined) {
             content = possibleContents;
         } else {
             // Outside editor, just use the cell
@@ -558,8 +558,8 @@ export class NativeCell extends React.Component<INativeCellProps> {
     private renderMiddleToolbar = () => {
         const cellId = this.props.cellVM.cell.id;
         const runCell = () => {
-            this.props.stateController.updateCellSource(cellId);
-            this.runAndMove(concatMultilineStringInput(this.props.cellVM.cell.data.source));
+            const contents = this.props.stateController.getMonacoEditorContents(cellId);
+            this.runAndMove(contents);
             this.props.stateController.sendCommand(NativeCommandType.Run, 'mouse');
         };
         const gatherCell = () => {

src/datascience-ui/native-editor/nativeEditorStateController.ts

@@ -286,7 +286,7 @@ export class NativeEditorStateController extends MainStateController {
         if (index >= 0) {
             // Get the model source from the monaco editor
             const source = this.getMonacoEditorContents(cellId);
-            if (source) {
+            if (source !== undefined) {
                 const newVMs = [...this.getState().cellVMs];
 
                 // Update our state