Data Viewer is blank when using Bluloco theme

[vishwa-raj]

Bug: Notebook Editor, Interactive Window, Editor cells

Steps to cause the bug to occur

1. Install Bluloco theme (dark or light)
2. Create a blank Jupyter notebook with the Python extension.
3. Create a list variable (or a numpy array, pandas series, etc..)
4. Open variable explorer
5. Open the data viewer for variable created in step 3.

Actual behavior

The data viewer is blank

Expected behavior

The data should be visible in the data viewer

Your Jupyter and/or Python environment

Please provide as much info as you readily know

• Jupyter server running: Local
• Extension version: 2019.11.50794
• VS Code version: 1.41.1
• Setting python.jediEnabled: tried both true and false
• Python: 3.6.9
• OS: Windows
• Virtual environment: conda

Developer Tools Console Output

[Extension Host] Info Python Extension: 2019-12-20 22:15:28: Using colors to generate CSS ...
console.ts:137 [Extension Host] Error Python Extension: 2019-12-20 22:15:28: [TypeError: e.tokenColors.forEach is not a function at y.generateMonacoThemeObject (c:\Users\pc.vscode\extensions\ms-python.python-2019.11.50794\out\client\extension.js:75:613378) at y.applyThemeData (c:\Users\pc.vscode\extensions\ms-python.python-2019.11.50794\out\client\extension.js:75:611834) at async C.handleMonacoThemeRequest (c:\Users\pc.vscode\extensions\ms-python.python-2019.11.50794\out\client\extension.js:1:429083)]
t.log @ console.ts:137
$logExtensionHostMessage @ mainThreadConsole.ts:39
_doInvokeHandler @ rpcProtocol.ts:398
_invokeHandler @ rpcProtocol.ts:383
_receiveRequest @ rpcProtocol.ts:299
_receiveOneMessage @ rpcProtocol.ts:226
(anonymous) @ rpcProtocol.ts:101
fire @ event.ts:581
fire @ ipc.net.ts:453
_receiveMessage @ ipc.net.ts:733
(anonymous) @ ipc.net.ts:592
fire @ event.ts:581
acceptChunk @ ipc.net.ts:239
(anonymous) @ ipc.net.ts:200
t @ ipc.net.ts:28
emit @ events.js:200
addChunk @ _stream_readable.js:294
readableAddChunk @ _stream_readable.js:275
Readable.push @ _stream_readable.js:210
onStreamRead @ internal/stream_base_commons.js:166
console.ts:137 [Extension Host] Info Python Extension: 2019-12-20 22:15:28: Using colors to generate CSS ...
console.ts:137 [Extension Host] Error Python Extension: 2019-12-20 22:15:28: [TypeError: e.findIndex is not a function at y.matchTokenColor (c:\Users\pc.vscode\extensions\ms-python.python-2019.11.50794\out\client\extension.js:75:612192) at y.getScopeStyle (c:\Users\pc.vscode\extensions\ms-python.python-2019.11.50794\out\client\extension.js:75:608805) at y.generateCss (c:\Users\pc.vscode\extensions\ms-python.python-2019.11.50794\out\client\extension.js:75:612411) at y.applyThemeData (c:\Users\pc.vscode\extensions\ms-python.python-2019.11.50794\out\client\extension.js:75:611834) at async C.handleCssRequest (c:\Users\pc.vscode\extensions\ms-python.python-2019.11.50794\out\client\extension.js:1:428767)]
t.log @ console.ts:137
$logExtensionHostMessage @ mainThreadConsole.ts:39
_doInvokeHandler @ rpcProtocol.ts:398
_invokeHandler @ rpcProtocol.ts:383
_receiveRequest @ rpcProtocol.ts:299
_receiveOneMessage @ rpcProtocol.ts:226
(anonymous) @ rpcProtocol.ts:101
fire @ event.ts:581
fire @ ipc.net.ts:453
_receiveMessage @ ipc.net.ts:733
(anonymous) @ ipc.net.ts:592
fire @ event.ts:581
acceptChunk @ ipc.net.ts:239
(anonymous) @ ipc.net.ts:200
t @ ipc.net.ts:28
emit @ events.js:200
addChunk @ _stream_readable.js:294
readableAddChunk @ _stream_readable.js:275
Readable.push @ _stream_readable.js:210
onStreamRead @ internal/stream_base_commons.js:166
webviewElement.ts:241 [Embedded Page] Uncaught (in promise) Error: Illegal theme base!

Microsoft Data Science for VS Code Engineering Team: @rchiodo, @IanMatthewHuff, @DavidKutu, @DonJayamanne, @greazer

[rchiodo]

Thanks for the bug. Seems this theme is using another layer of indirection for token colors.

We need to fix this line here:
https://github.com/microsoft/vscode-python/blob/bb158391441f54a5284eaf593f87c547fde745a8/src/client/datascience/codeCssGenerator.ts#L337
It is assuming tokenColors is an array, when it can also be a file.

[rchiodo]

A crash here prevents the theme from being loaded, and prevents the viewer from opening.

[rchiodo]

So we should also harden the theme parsing to at least return the default on a theme crash.

[joshuajaharwood]

Bug also occurs with the Ariake Dark 0.2.2 in VS Code 1.41.1.

[rchiodo]

Validated