Add setting use brackets as a namespace separator

[alxfv]

Add a new setting that allows using square brackets as a namespace separator.

In a company I work for we use square brackets as a struct separator.

• [*] Tests exist or have been written that cover this particular change.

@go-playground/admins

[coveralls]

Coverage remained the same at 100.0% when pulling 11d2b17 on alxfv:use-brackets-as-namespace-separator into e56bbb1 on go-playground:master.

[deankarn]

@alxfv I will have to review carefully, there is a good chance this will conflict with the map and/or array decoding logic which uses square brackets as its separators.

[alxfv]

@alxfv I will have to review carefully, there is a good chance this will conflict with the map and/or array decoding logic which uses square brackets as its separators.

Thanks! I will add more tests to try to find possible conflicts.

[alxfv]

Hello again!

Improved some tests:

1. Use table tests to run tests with and without useBrackest setting.
2. Added in TestDecoderStruct all cases from TestDecoderMapKeys and haven't found any issues with decoding structs and map with square brackets in the same values.
3. Added TestTestDecoderStructMapConflict that shows what happens if map key and struct field have the same value:
   

   form/decoder_test.go

   Lines 537 to 585 in ad71d56

   	func TestDecoderEqualStructMapValue(t *testing.T) {
   	type PhoneStruct struct {
   	Number string
   	}
   	type PhoneMap map[string]string
   	type TestStruct struct {
   	PhoneStruct PhoneStruct `form:"Phone"`
   	PhoneMap PhoneMap `form:"Phone"`
   	}
   	testCases := []struct {
   	UseBrackets bool
   	Values url.Values
   	}{{
   	UseBrackets: false,
   	Values: url.Values{
   	"Phone.Number": []string{"111"},
   	"Phone[Number]": []string{"222"},
   	},
   	}, {
   	UseBrackets: true,
   	Values: url.Values{
   	"Phone[Number]": []string{"111"},
   	},
   	}}
   	for _, tc := range testCases {
   	tc := tc
   	t.Run(fmt.Sprintf("useBrackets_%v", tc.UseBrackets), func(t *testing.T) {
   	decoder := NewDecoder()
   	decoder.SetUseBrackets(tc.UseBrackets)
   	var test TestStruct
   	err := decoder.Decode(&test, tc.Values)
   	Equal(t, err, nil)
   	Equal(t, test.PhoneStruct.Number, "111")
   	if tc.UseBrackets == false {
   	Equal(t, test.PhoneMap["Number"], "222")
   	} else {
   	Equal(t, test.PhoneMap["Number"], "111")
   	}
   	})
   	}
   	}

"Phone[Number]": []string{"111"}, with usingBrackets = true will be decoded to struct or/and a map and it looks as expected.

Also wanted to tell how this pull request implements this feature. It changes only namespace slice here:

form/decoder.go

Lines 162 to 169 in 91efee7

	if d.d.useBrackets {
	namespace = append(namespace, '[')
	namespace = append(namespace, f.name...)
	namespace = append(namespace, ']')
	} else {
	namespace = append(namespace, namespaceSeparator)
	namespace = append(namespace, f.name...)
	}

And later on in findAlias we will get Phone[Number] instead of Phone.Number, that's all.

form/decoder.go

Lines 34 to 41 in 91efee7

	func (d *decoder) findAlias(ns string) *recursiveData {
	for i := 0; i < len(d.dm); i++ {
	if d.dm[i].alias == ns {
	return d.dm[i]
	}
	}
	return nil
	}

[deankarn]

I think that this will likely be ok then.

I only have one ask to make this more generic for any future requests can the PR be modified to use a struct namespace prefix and struct namespace suffix?

This will help keep the library flexible to future use cases and remove the if logic associated with useBarackets :)

[alxfv]

I think that this will likely be ok then.

I only have one ask to make this more generic for any future requests can the PR be modified to use a struct namespace prefix and struct namespace suffix?

This will help keep the library flexible to future use cases and remove the if logic associated with useBarackets :)

Great idea! Done.