No text in cell created with createCodeCell

[tanya94]

Description

I try to write an extension, which creates new code cell in active notebook panel. I have this code:

const nbContentModel = this.nbTracker.currentWidget.content.model;
const codeCell = nbContentModel.contentFactory.createCodeCell({
            cell: {
              cell_type: `code`, 
              source: [
                `some code line 1`,
                `some code line 2`
              ],
              metadata: {},
            }
          });

const cells = nbContentModel.cells;
cells.insert(cells.length, codeCell);
this.nbTracker.currentWidget.content.activeCellIndex = insertingIndex;
nbContentModel.initialize();
this.nbTracker.activeCell.editor.focus();

Next I open notebook tab and there is new cell, but it is empty until I click on it manually.

It looks like this (I have new active cell, but it's empty):

Context

Operating System and version: macOS Catalina 10.15
Browser and version: Chrome 80.0.3987.100

> jupyter --version
jupyter core     : 4.6.1
jupyter-notebook : 6.0.3
qtconsole        : 4.6.0
ipython          : 7.11.1
ipykernel        : 5.1.4
jupyter client   : 5.3.4
jupyter lab      : 1.2.6
nbconvert        : 5.6.1
ipywidgets       : 7.5.1
nbformat         : 5.0.4
traitlets        : 4.3.3

[jasongrout]

but it is empty until I click on it manually

To be clear, what happens when you click on it?

[tanya94]

To be clear, what happens when you click on it?

Text some code line 1, some code line 2 in the cell appears :)

[jasongrout]

Thanks. So perhaps the codemirror cell is not getting refreshed or something on creation. Setting as Future for someone to investigate - if you have time to look into it and submit a PR, that would be great.

[dLamSlo8]

Is this still an issue in the newest version of JupyterLab? I'm testing it on my end and the cell content seems to be showing up without the need to click on it.