Match/filter

[LuitelSamikshya]

closes #575

[Mzack9999]

$ go run . -d example.com -match "megalom.*" -silent
megalom.example.com
$ go run . -d example.com -filter "megalom.*" -silent | wc -l
   22800

[forgedhallpass]

This functionality requires extensive tests with positive and negative scenarios!

[Mzack9999]

The following test will fail:

t.Run("Filter and Match", func(t *testing.T) {
	options.Filter = []string{"example.com"}
	options.Match = []string{"www.example.com"}
	err := options.validateOptions()
	if err != nil {
		t.Fatalf("Expected nil got %v while validation\n", err)
	}
	runner, err := NewRunner(options)
	if err != nil {
		t.Fatalf("Expected nil got %v while creating runner\n", err)
	}
	subdomain := []string{"example.com", "www.example.com"}
	for _, sub := range subdomain {
		match := runner.filterAndMatchSubdomain(sub)
		require.True(t, match, "Expecting a boolean True value ")
	}
})

While compiling the regexes, I think we need to use anchors (^ and $) for those not containing wildcards (e.g. example.com => ^example\.com$). Otherwise, all strings containing the regular expression value will match.

tests were added