Display code errors in red in real time

[JulienLecoq]

Describe the request

I would like to have code errors appears in real time on screen (before compilation as does other IDEs)

Describe the current behavior

Code errors are only printed inside the Output section of the IDE on Verify/Upload buttons click.

Arduino IDE version

2.0.2

Operating system

Linux

Operating system version

I'm using Garuda Linux, according to lsb_release -a : "Talon"

Additional context

No response

Issue checklist

• I searched for previous requests in the issue tracker
• I verified the feature was still missing when using the latest nightly build
• My request contains all necessary details

[per1234]

Hi @JulienLecoq. Thanks for your suggestion.

I'm happy to tell you Arduino IDE already has this capability. It can be enabled via the advanced settings:

1. Press the Ctrl+Shift+P keyboard shortcut (Command+Shift+P for macOS users) to open the "Command Palette".
2. Select the "Preferences: Open Settings (UI)" command from the menu.
3. A "Preferences" tab will now open in the Arduino IDE main panel. In the "Search Settings" field, type arduino.language.realTimeDiagnostics
4. Check the checkbox under the "Arduino › Language: Real Time Diagnostics" setting.
5. Close the Preferences tab by clicking its X icon.

It is important to understand the reason why it was decided to have this setting off by default. Library discovery is a convenient feature of the Arduino build system. It allows you to use any library in your sketch simply by adding an #include directive for a header file. In order to accomplish that, the Arduino IDE must search through all the library locations.

Previously, Arduino IDE 2.x triggered the library discovery process on every change to the sketch code. In order to reduce the resource usage, the IDE has now been changed to use only the following events as library discovery triggers (#1107):

• Opening a sketch.
• Changing the board selection.
• Compiling the sketch

For this reason, the language server features will not work for sketch code that uses a library during the interval between when its #include directive was added to the sketch and when the library discovery is next triggered.

The deferred library discovery technique described above results in spurious problem detection for uses of the library in the sketch code before a discovery process is triggered.

[JulienLecoq]

Oh okay, thanks for your very detailed response @per1234 !