From 05a0d086fc2ba40bd19ca0faf8be44585b68d413 Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@lunar-ocean.com>
Date: Thu, 14 Mar 2024 13:25:06 -0700
Subject: [PATCH] bring back test in config as well

---
 component/config.go      |  2 +-
 component/config_test.go | 26 ++++++++++++++++++++++++++
 confmap/confmap.go       | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/component/config.go b/component/config.go
index de7006b6a07..f305b253ae6 100644
--- a/component/config.go
+++ b/component/config.go
@@ -27,7 +27,7 @@ type Config any
 var configValidatorType = reflect.TypeOf((*ConfigValidator)(nil)).Elem()
 
 // UnmarshalConfig helper function to UnmarshalConfig a Config.
-// Deprecated: [v0.97.0] Use conf.Unmarshal(&intoCfg)
+// Deprecated: [v0.99.0] Use conf.Unmarshal(&intoCfg)
 func UnmarshalConfig(conf *confmap.Conf, intoCfg Config) error {
 	return conf.Unmarshal(intoCfg)
 }
diff --git a/component/config_test.go b/component/config_test.go
index f47a9edc87c..f85511cbe3a 100644
--- a/component/config_test.go
+++ b/component/config_test.go
@@ -12,6 +12,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	"go.opentelemetry.io/collector/confmap"
 )
 
 var _ fmt.Stringer = Type{}
@@ -420,3 +422,27 @@ func TestNewType(t *testing.T) {
 		})
 	}
 }
+
+type configWithEmbeddedStruct struct {
+	String                      string `mapstructure:"string"`
+	Num                         int    `mapstructure:"num"`
+	EmbeddedUnmarshallingConfig `mapstructure:",squash"`
+}
+
+type EmbeddedUnmarshallingConfig struct {
+}
+
+func (euc *EmbeddedUnmarshallingConfig) Unmarshal(_ *confmap.Conf) error {
+	return nil // do nothing.
+}
+func TestStructWithEmbeddedUnmarshaling(t *testing.T) {
+	cfgMap := confmap.NewFromStringMap(map[string]any{
+		"string": "foo",
+		"num":    123,
+	})
+	tc := &configWithEmbeddedStruct{}
+	err := UnmarshalConfig(cfgMap, tc)
+	require.NoError(t, err)
+	assert.Equal(t, "foo", tc.String)
+	assert.Equal(t, 123, tc.Num)
+}
diff --git a/confmap/confmap.go b/confmap/confmap.go
index 4680af673be..a900b421f87 100644
--- a/confmap/confmap.go
+++ b/confmap/confmap.go
@@ -422,3 +422,36 @@ func zeroSliceHookFunc() mapstructure.DecodeHookFuncValue {
 		return from.Interface(), nil
 	}
 }
+
+// This hook is used to solve the issue: https://github.com/open-telemetry/opentelemetry-collector/issues/9060
+// Decoding should fail when converting a negative integer to any type of unsigned integer. This prevents
+// negative values being decoded as large uint values.
+// TODO: This should be removed as a part of https://github.com/open-telemetry/opentelemetry-collector/issues/9532
+func negativeUintHookFunc() mapstructure.DecodeHookFuncValue {
+	return func(from reflect.Value, to reflect.Value) (interface{}, error) {
+		if from.CanInt() && from.Int() < 0 && to.CanUint() {
+			return nil, fmt.Errorf("cannot convert negative value %v to an unsigned integer", from.Int())
+		}
+		return from.Interface(), nil
+	}
+}
+
+type moduleFactory[T any, S any] interface {
+	Create(s S) T
+}
+
+type createConfmapFunc[T any, S any] func(s S) T
+
+type confmapModuleFactory[T any, S any] struct {
+	f createConfmapFunc[T, S]
+}
+
+func (c confmapModuleFactory[T, S]) Create(s S) T {
+	return c.f(s)
+}
+
+func newConfmapModuleFactory[T any, S any](f createConfmapFunc[T, S]) moduleFactory[T, S] {
+	return confmapModuleFactory[T, S]{
+		f: f,
+	}
+}