[v2] Add -devtools production build flag

[mmghv]

Description

This adds the build flag -devtools which enables the devtools in production when -debug is not used.

Using -debug automatically enables devtools but it also includes go debug info which increases the binary size and shows the debug console window, sometimes you only need the ability to show the devtools in production build in personal projects to be able to debug the frontend on the fly.

Note: -debug alone still enables the devtools.
Note: options.Debug.OpenInspectorOnStartup still only works with -debug.

Fixes #1523

Type of change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

How Has This Been Tested?

• Windows
• macOS
• Linux

Here's how to test it :

1- Create a new project wails init -n testproject -t vanilla
2- Follow these instructions (replace [IDofThePR] with 2725), and make sure to add the replace directive in go.mod.
3- Change testproject/main.go to add this option, which needs be updated according to the test table :

func main() {
	// ...
	err := wails.Run(&options.App{
		// ...
		Debug: options.Debug{
			OpenInspectorOnStartup: false,
        	},
	})
	// ...
}

4- Build the application according to the following table and ensure the expected behavior in each case:

OpenInspectorOnStartup	Command	Expected behavior
false	wails build	no console window, no context menu
false	wails build -debug	console window + context menu & devtools AVAILABLE
true	wails build -debug	same as ^ + devtools opens on startup
false	wails build -devtools	no console window, context menu & devdools AVAILABLE
true	wails build -devtools	same as ^ (devtools SHOULD NOT open on startup)
false	wails dev	console window + context menu with devtools
true	wails dev	same as ^ + devtools opens on startup

(To make it easier you could do all tests where OpenInspectorOnStartup is false first, then change it to true and do the other tests)

Test Configuration

wails doctor

# Wails
Version  | v2.5.1
Revision | 5722b944a426565cf56556ae3a27d64893561825
Modified | false

# System
┌────────────────────────────────────┐
| OS           | Windows 10 Pro      |
| Version      | 2009 (Build: 19045) |
| ID           | 22H2                |
| Go Version   | go1.20.4            |
| Platform     | windows             |
| Architecture | amd64               |
└────────────────────────────────────┘

# Dependencies
┌───────────────────────────────────────────────────────┐
| Dependency | Package Name | Status    | Version       |
| WebView2   | N/A          | Installed | 114.0.1823.43 |
| Nodejs     | N/A          | Installed | 18.14.1       |
| npm        | N/A          | Installed | 9.3.1         |
| *upx       | N/A          | Installed | upx 4.0.2     |
| *nsis      | N/A          | Available |               |
└─────────────── * - Optional Dependency ───────────────┘

# Diagnosis
Optional package(s) installation details:
  - nsis : More info at https://wails.io/docs/guides/windows-installer/

Checklist:

• I have updated website/src/pages/changelog.mdx with details of this PR
• My code follows the general coding style of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[mmghv]

Tested on Linux, all cases work as expected.

wails doctor

Version         | v2.5.1
Revision        | 4f886e180ea296f79e58864143e56ca8fdb00b5a
Modified        | false
Package Manager | apt

# System
┌─────────────────────────┐
| OS           | Ubuntu   |
| Version      | 22.04    |
| ID           | ubuntu   |
| Go Version   | go1.20.5 |
| Platform     | linux    |
| Architecture | amd64    |
└─────────────────────────┘

# Dependencies
┌──────────────────────────────────────────────────────────────────────────┐
| Dependency | Package Name          | Status    | Version                 |
| *docker    | docker.io             | Installed |                         |
| gcc        | build-essential       | Installed | 11.3.0                  |
| libgtk-3   | libgtk-3-dev          | Installed | 3.24.33-1ubuntu2        |
| libwebkit  | libwebkit2gtk-4.0-dev | Installed | 2.38.6-0ubuntu0.22.04.1 |
| npm        | npm                   | Installed | 9.5.1                   |
| *nsis      | nsis                  | Available | 3.08-2                  |
| pkg-config | pkg-config            | Installed | 0.29.2-1ubuntu3         |
└──────────────────────── * - Optional Dependency ─────────────────────────┘

# Diagnosis
Optional package(s) installation details:
  - nsis: sudo apt install nsis

 SUCCESS  Your system is ready for Wails development!

@leaanthony Please test on macOS

[leaanthony]

@mmghv - When you say "Console window", do you mean the terminal which we use to run the app?

I've tested the scenarios above, but if I use runtime.LogErrorf(ctx, "App started") in app start, I can still see it in the console when using -devtools.

[mmghv]

@leaanthony

When you say "Console window", do you mean the terminal which we use to run the app?

Yes, in debug mode on windows if I launch the app from file explorer, I get a terminal window in addition to the main window (that's why this feature was needed in the first place).
But if you run the app from the terminal, you will get the output there and won't get additional terminal window.

Anyway, when using -devtools you should see in the terminal the same you see when you build a normal app wails build, you see logError because it's the default loglevel in production.

If you instead did runtime.LogInfo(ctx, "App started") you should see it in debug mode only, I'm not sure of a better way to tell if you're in debug mode when running from the terminal, on linux I judged by the binary size.

[leaanthony]

I tested on MacOS and it appeared to do what you would expect. I'm happy with this so far. Feel free to mark it ready for review when you are ready.

[mmghv]

All ready, @stffabi you worked on this area of the code, could you please review it?

[stffabi]

LGTM 👍 , thanks for doing this and taking your time.