tgbotapi.NewWebhook ignores error on invalid url

[kortov]

Here's an error is ignored

telegram-bot-api/helpers.go

Lines 394 to 400 in aa124ef

	func NewWebhook(link string) WebhookConfig {
	u, _ := url.Parse(link)
	return WebhookConfig{
	URL: u,
	}
	}

so when you pass an url like "https://example.com" + bot.Token here (and I think it's easy to do such mistake)

telegram-bot-api/bot_test.go

Line 490 in aa124ef

wh := tgbotapi.NewWebhook("https://example.com/tgbotapi-test/" + bot.Token)

the test (and bot of course) fails with this

=== RUN   TestSetWebhookWithoutCert
2020/02/29 22:51:04 setWebhook resp: {"ok":true,"result":true,"description":"Webhook is already deleted"}
--- FAIL: TestSetWebhookWithoutCert (2.83s)
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
	panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x5d6e4a]

goroutine 6 [running]:
testing.tRunner.func1(0xc0000e4100)
	/snap/go/5364/src/testing/testing.go:874 +0x3a3
panic(0x71b060, 0x9fd7f0)
	/snap/go/5364/src/runtime/panic.go:679 +0x1b2
net/url.(*URL).String(0x0, 0xc000001980, 0x300000002)
	/snap/go/5364/src/net/url/url.go:775 +0x4a
github.com/go-telegram-bot-api/telegram-bot-api.(*BotAPI).SetWebhook(0xc0000ea000, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
	/home/user/GolandProjects/telegram-bot-api/bot.go:454 +0x3c8
github.com/go-telegram-bot-api/telegram-bot-api_test.TestSetWebhookWithoutCert(0xc0000e4100)
	/home/user/GolandProjects/telegram-bot-api/bot_test.go:491 +0x15d
testing.tRunner(0xc0000e4100, 0x799998)
	/snap/go/5364/src/testing/testing.go:909 +0xc9
created by testing.(*T).Run
	/snap/go/5364/src/testing/testing.go:960 +0x350

Process finished with exit code 1

[ErrorBoi]

I've figured out, that error occurs, when program is trying to parse given URL (like "https://example.com" + bot.Token) in NewWebhook() or NewWebhookWithCert().

It fails, because bot token contains a colon and parser suggests, that part after colon is port.
My proposal is to handle error from url.Parse() instead of ingoring it, and if err != nil, return empty WebhookConfig.

According tests should fail with custom error, if Webhook.URL == nil.

[ErrorBoi]

Fixed this issue and created pull request, made in accordance with my plan in comment above. Please let me know if solution is not proper, I will fix it.

[Syfaro]

Given that panics should generally be avoided, it would be a good idea to return the error.

There's already a few breaking changes in v5 for correctness reasons, adding another wouldn't be so bad.

[Syfaro]

NewWebhook now returns an error.

telegram-bot-api/helpers.go

Lines 300 to 303 in 2a2f7c5

	// NewWebhook creates a new webhook.
	//
	// link is the url parsable link you wish to get the updates.
	func NewWebhook(link string) (WebhookConfig, error) {