Feature/terms aggs missing features (#56)

* feature: add missing and script for termsAggType

* chore: format import on aggregation_terms_test.go

* chore: fix typo

Author: GokselKUCUKSAHIN

es/aggregation_terms.go

@@ -29,6 +29,39 @@ func TermsAgg(field string) termsAggType {
 	}
 }
 
+// Missing sets a default value to use for documents that do not contain the field.
+//
+// Example usage:
+//
+//	agg := es.TermsAgg("category").Missing("unknown")
+//	// Documents without "category" will be assigned "unknown".
+//
+// Parameters:
+//   - missing: The value to use when a document lacks the field.
+//
+// Returns:
+//
+//	An es.termsAggType object with the "missing" field set.
+func (terms termsAggType) Missing(missing any) termsAggType {
+	return terms.putInTheField("missing", missing)
+}
+
+// Script sets a script to compute dynamic bucket values instead of using a field.
+//
+// Example usage:
+//
+//	agg := es.TermsAgg("category").Script(es.ScriptSource("doc['category'].value + '_modified'", ScriptLanguage.Painless))
+//
+// Parameters:
+//   - script: A script for computing dynamic term values.
+//
+// Returns:
+//
+//	An es.termsAggType object with the "script" field set.
+func (terms termsAggType) Script(script scriptType) termsAggType {
+	return terms.putInTheField("script", script)
+}
+
 // Size sets the number of term buckets to return.
 //
 // Example usage:

es/aggregation_terms_test.go

@@ -6,6 +6,7 @@ import (
 	CollectMode "github.com/Trendyol/es-query-builder/es/enums/collect-mode"
 	ExecutionHint "github.com/Trendyol/es-query-builder/es/enums/execution-hint"
 	Order "github.com/Trendyol/es-query-builder/es/enums/sort/order"
+	ScriptLanguage "github.com/Trendyol/es-query-builder/es/enums/script-language"
 
 	"github.com/Trendyol/es-query-builder/es"
 	"github.com/Trendyol/es-query-builder/test/assert"
@@ -39,6 +40,49 @@ func Test_TermsAgg_should_create_json_with_terms_field_inside(t *testing.T) {
 	assert.Equal(t, "{\"terms\":{\"field\":\"price\"}}", bodyJSON)
 }
 
+func Test_TermsAgg_should_have_Missing_method(t *testing.T) {
+	t.Parallel()
+	// Given
+	a := es.TermsAgg("price")
+
+	// When Then
+	assert.NotNil(t, a.Missing)
+}
+
+func Test_Missing_should_add_missing_field_into_TermsAgg(t *testing.T) {
+	t.Parallel()
+	// Given
+	a := es.TermsAgg("price").
+		Missing("missing_name")
+
+	// When Then
+	assert.NotNil(t, a)
+	bodyJSON := assert.MarshalWithoutError(t, a)
+	assert.Equal(t, "{\"terms\":{\"field\":\"price\",\"missing\":\"missing_name\"}}", bodyJSON)
+}
+
+func Test_TermsAgg_should_have_Script_method(t *testing.T) {
+	t.Parallel()
+	// Given
+	a := es.TermsAgg("price")
+
+	// When Then
+	assert.NotNil(t, a.Script)
+}
+
+func Test_Script_should_add_script_field_into_TermsAgg(t *testing.T) {
+	t.Parallel()
+	// Given
+	a := es.TermsAgg("price").
+		Script(es.ScriptID("id_12345", ScriptLanguage.Painless))
+
+	// When Then
+	assert.NotNil(t, a)
+	bodyJSON := assert.MarshalWithoutError(t, a)
+	// nolint:golint,lll
+	assert.Equal(t, "{\"terms\":{\"field\":\"price\",\"script\":{\"id\":\"id_12345\",\"lang\":\"painless\"}}}", bodyJSON)
+}
+
 func Test_TermsAgg_should_have_ShowTermDocCountError_method(t *testing.T) {
 	t.Parallel()
 	// Given