[BUG] Nested struct with required field is not failing on decode

[gaaral]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

The decoder doesn't fail if a required property of the nested struct is not populated.

Expected Behavior

The decoder should throw an error if a required field is missing in the nested struct.

Steps To Reproduce

Test

func TestDecoder(t *testing.T) {
	type Bar struct {
		Baz string `json:"baz,required"`
		Qux string `json:"qux"`
	}

	type Foo struct {
		Field string `json:"field,required"`
		Bars  []Bar  `json:"bars"`
	}

	t.Run("should test nested struct", func(t *testing.T) {
		payload := map[string][]string{
			"field":      {"foo"},
			"bars.0.baz": {"baz"},
		}

		d := schema.NewDecoder()
		d.SetAliasTag("json")

		var foo Foo
		err := d.Decode(&foo, payload)

		assert.Nil(t, err)
	})

	t.Run("should fail on bars.0.baz", func(t *testing.T) {
		payload := map[string][]string{
			"field":      {"foo"},
			"bars.0.qux": {"qux"},
		}

		d := schema.NewDecoder()
		d.SetAliasTag("json")

		var foo Foo
		err := d.Decode(&foo, payload)

		assert.Error(t, err, "bars.0.baz is empty")
		assert.NotNil(t, err)
	})

	t.Run("should fail for field", func(t *testing.T) {
		payload := map[string][]string{
			"bars.0.baz": {"baz"},
		}

		d := schema.NewDecoder()
		d.SetAliasTag("json")

		var foo Foo
		err := d.Decode(&foo, payload)

		assert.Error(t, err, "field is empty")
		assert.NotNil(t, err)
	})
}

Result

=== RUN   TestDecoder
=== RUN   TestDecoder/should_test_nested_struct
=== RUN   TestDecoder/should_fail_on_bars.0.baz
    api_test.go:291: 
        	Error Trace:
        	Error:      	An error is expected but got nil.
        	Test:       	TestDecoder/should_fail_on_bars.0.baz
        	Messages:   	bars.0.baz is empty
    api_test.go:292: 
        	Error Trace:
        	Error:      	Expected value not to be nil.
        	Test:       	TestDecoder/should_fail_on_bars.0.baz
=== RUN   TestDecoder/should_fail_for_field
--- FAIL: TestDecoder (0.00s)
    --- PASS: TestDecoder/should_test_nested_struct (0.00s)
    --- FAIL: TestDecoder/should_fail_on_bars.0.baz (0.00s)

    --- PASS: TestDecoder/should_fail_for_field (0.00s)

FAIL

Anything else?

No response