✨ support logging color for custom logging formats

[amalshaji]

Support logger coloring for custom logging formats

Add a function to check for a valid custom format. A valid format is one having both ${status} and ${method}. Fixed #1467

[ReneWerner87]

can you please provide unittests that test the new code in use and make sure what we expect happens

[amalshaji]

How to test for colors in output? Or test the newly added function?

[ReneWerner87]

Use a buffer as weitter in the configuration and check the generated output.

[ReneWerner87]

@amalshaji any progress ?
you could test the feature in the test and define a buffer as the writer in the config and then check the created output
-> color output has a special prefix and suffix

[amalshaji]

working on it now

[amalshaji]

if validCustomFormat(cfg.Format) && cfg.Output == nil {
    cfg.enableColors = true
}

If I use buf as Output, the colors won't be enabled!

[ReneWerner87]

ok then use my function to capture the output
https://github.com/gofiber/fiber/blob/master/app_test.go#L1263-L1291

[ReneWerner87]

@amalshaji can you please create the tests

[amalshaji]

I'm using your function to capture the output. The following code is used for testing the output:

func Test_Logger_Custom_Format_Color(t *testing.T) {
	output := captureOutput(func() {
		app := fiber.New()
		app.Use(New(Config{
			Format: "",
		}))
		app.Test(httptest.NewRequest("GET", "/test", nil))
	})
	fmt.Println("captured Output: ", output)
	utils.AssertEqual(t, 5, 5)
}

When the format is "", I get:

❯ go test -timeout 30s -run ^Test_Logger_Custom_Format_Color
captured Output:  18:32:03 | 404 |      0s |         0.0.0.0 | GET     | /test

PASS
ok      github.com/gofiber/fiber/v2/middleware/logger   0.004s

When I use a custom template like ${status}, I get:

❯ go test -timeout 30s -run ^Test_Logger_Custom_Format_Color
404captured Output:
PASS
ok      github.com/gofiber/fiber/v2/middleware/logger   0.005s

No output is being captured. Note the 404 printed to stdout.

So I decided to disable the validCustomTemplate function and use the previous check, i.e., if cfg.Format == "" && ...

Got the same output as the empty format one. Unfortunately, the output does not capture any color tags. Also, no color tests were done previously, so I can't refer.

[amalshaji]

go run main.go prints color to output. But fiber dev doesn't. Is this related to my problem?

[ReneWerner87]

Yes should be, you can open a issue in https://github.com/gofiber/cli

[ReneWerner87]

@amalshaji that means we do not need the pull request ? the normally come the colors yes or ?

[amalshaji]

Only when the format is "" (Empty). The issue was to support colors for custom format. I can't figure out how to test for colors.

[ReneWerner87]

@amalshaji thx for the contribution and effort

have unfortunately also found no way

from the code it looks good