[chore][pkg/stanza] prevent unkeyed literal initialization (open-telemetry#43864)

Author: atoulme

pkg/stanza/entry/attribute_field.go

@@ -22,9 +22,11 @@ func NewAttributeField(keys ...string) Field {
 	if keys == nil {
 		keys = []string{}
 	}
-	return Field{AttributeField{
-		Keys: keys,
-	}}
+	return Field{
+		FieldInterface: AttributeField{
+			Keys: keys,
+		},
+	}
 }
 
 // Parent returns the parent of the current field.

pkg/stanza/entry/body_field.go

@@ -21,7 +21,7 @@ func NewBodyField(keys ...string) Field {
 	if keys == nil {
 		keys = []string{}
 	}
-	return Field{BodyField{
+	return Field{FieldInterface: BodyField{
 		Keys: keys,
 	}}
 }

pkg/stanza/entry/entry_test.go

@@ -225,9 +225,11 @@ func TestFieldFromString(t *testing.T) {
 			output: Field{FieldInterface: AttributeField{Keys: []string{"test", "foo", "bar"}}},
 		},
 		{
-			name:   "SimpleResource",
-			input:  "resource.test",
-			output: Field{ResourceField{Keys: []string{"test"}}},
+			name:  "SimpleResource",
+			input: "resource.test",
+			output: Field{
+				FieldInterface: ResourceField{Keys: []string{"test"}},
+			},
 		},
 		{
 			name:   "NestedResource",

pkg/stanza/entry/field.go

@@ -21,6 +21,8 @@ const (
 // It is deserialized from JSON dot notation.
 type Field struct {
 	FieldInterface
+	// prevent unkeyed literal initialization
+	_ struct{}
 }
 
 // RootableField is a Field that may refer directly to "attributes" or "resource"

pkg/stanza/entry/nil_field.go

@@ -32,5 +32,5 @@ func (NilField) String() string {
 
 // NewNilField will create a new nil field
 func NewNilField() Field {
-	return Field{NilField{}}
+	return Field{FieldInterface: NilField{}}
 }

pkg/stanza/entry/resource_field.go

@@ -22,7 +22,7 @@ func NewResourceField(keys ...string) Field {
 	if keys == nil {
 		keys = []string{}
 	}
-	return Field{ResourceField{
+	return Field{FieldInterface: ResourceField{
 		Keys: keys,
 	}}
 }
@@ -219,6 +219,8 @@ func (f *ResourceField) UnmarshalText(text []byte) error {
 		return fmt.Errorf("must start with 'resource': %s", text)
 	}
 
-	*f = ResourceField{Keys: keys[1:]}
+	*f = ResourceField{
+		Keys: keys[1:],
+	}
 	return nil
 }

pkg/stanza/operator/helper/output.go

@@ -41,6 +41,8 @@ func (c OutputConfig) Build(set component.TelemetrySettings) (OutputOperator, er
 // OutputOperator provides a basic implementation of an output operator.
 type OutputOperator struct {
 	BasicOperator
+	// prevent unkeyed literal initialization
+	_ struct{}
 }
 
 // CanProcess will always return true for an output operator.