Add IfElse conditional branching support (#74)

es/condition/if_else.go

@@ -0,0 +1,92 @@
+package condition
+
+// Branch represents a conditional branch used in IfElse chains.
+// Create branches using ElseIf or Else functions.
+type Branch struct {
+	item      any
+	condition bool
+	isElse    bool
+}
+
+// ElseIf creates a conditional branch for use in IfElse.
+// The item is selected only if no previous condition was true and this condition is true.
+//
+// Parameters:
+//   - condition: A boolean that determines if `item` should be selected.
+//   - item: The value to return if this branch is selected.
+//
+// Returns:
+//
+//	A Branch to be passed to IfElse.
+//
+// Example usage:
+//
+//	condition.IfElse(x > 10, es.Term("foo", "bar"),
+//	    condition.ElseIf(y < 20, es.Exists("fizz")),
+//	)
+func ElseIf(condition bool, item any) Branch {
+	return Branch{condition: condition, item: item}
+}
+
+// Else creates a default branch for use in IfElse.
+// The item is selected when no previous condition was true.
+//
+// Parameters:
+//   - item: The value to return if no other condition matched.
+//
+// Returns:
+//
+//	A Branch to be passed as the last argument to IfElse.
+//
+// Example usage:
+//
+//	condition.IfElse(x > 10, es.Term("foo", "bar"),
+//	    condition.ElseIf(y < 20, es.Exists("fizz")),
+//	    condition.Else(es.Range("date").LesserThan("now-2h")),
+//	)
+func Else(item any) Branch {
+	return Branch{item: item, isElse: true}
+}
+
+// IfElse evaluates conditions in order and returns the item associated with the
+// first true condition. If no condition is true and no Else branch is provided,
+// it returns nil.
+//
+// Parameters:
+//   - condition: A boolean that determines if `item` should be returned.
+//   - item: The map or slice to return if the condition is true.
+//   - branches: Optional ElseIf and Else branches to evaluate in order.
+//
+// Returns:
+//
+//	The item from the first matching condition, the Else item, or nil.
+//
+// Example usage:
+//
+//	// Simple if
+//	condition.IfElse(x > 10, es.Term("foo", "bar"))
+//
+//	// if + elseIf
+//	condition.IfElse(x > 10, es.Term("foo", "bar"),
+//	    condition.ElseIf(y < 20, es.Exists("fizz")),
+//	)
+//
+//	// if + elseIf + else
+//	condition.IfElse(x > 10, es.Term("foo", "bar"),
+//	    condition.ElseIf(y < 20, es.Exists("fizz")),
+//	    condition.Else(es.Range("date").LesserThan("now-2h")),
+//	)
+func IfElse[T ~map[string]any | ~[]any](condition bool, item T, branches ...Branch) any {
+	if condition {
+		return item
+	}
+	for _, branch := range branches {
+		if branch.isElse {
+			return branch.item
+		}
+		if branch.condition {
+			return branch.item
+		}
+	}
+	return nil
+}

es/condition/if_else_test.go

@@ -0,0 +1,238 @@
+package condition_test
+
+import (
+	"testing"
+
+	"github.com/Trendyol/es-query-builder/es"
+	"github.com/Trendyol/es-query-builder/es/condition"
+	"github.com/Trendyol/es-query-builder/test/assert"
+)
+
+func Test_IfElse_should_return_item_when_condition_is_true(t *testing.T) {
+	t.Parallel()
+	// Given
+	x := 15
+
+	// When
+	query := es.NewQuery(
+		es.Bool().
+			Filter(
+				condition.IfElse(x > 10, es.Term("foo", "bar")),
+				es.Exists("brandId"),
+			),
+	)
+
+	// Then
+	assert.NotNil(t, query)
+	bodyJSON := assert.MarshalWithoutError(t, query)
+	// nolint:golint,lll
+	assert.Equal(t, "{\"query\":{\"bool\":{\"filter\":[{\"term\":{\"foo\":{\"value\":\"bar\"}}},{\"exists\":{\"field\":\"brandId\"}}]}}}", bodyJSON)
+}
+
+func Test_IfElse_should_return_nil_when_condition_is_false(t *testing.T) {
+	t.Parallel()
+	// Given
+	x := 5
+
+	// When
+	query := es.NewQuery(
+		es.Bool().
+			Filter(
+				condition.IfElse(x > 10, es.Term("foo", "bar")),
+				es.Exists("brandId"),
+			),
+	)
+
+	// Then
+	assert.NotNil(t, query)
+	bodyJSON := assert.MarshalWithoutError(t, query)
+	assert.Equal(t, "{\"query\":{\"bool\":{\"filter\":[{\"exists\":{\"field\":\"brandId\"}}]}}}", bodyJSON)
+}
+
+func Test_IfElse_ElseIf_should_return_elseIf_item_when_first_is_false_and_second_is_true(t *testing.T) {
+	t.Parallel()
+	// Given
+	x := 5
+	y := 10
+
+	// When
+	query := es.NewQuery(
+		es.Bool().
+			Filter(
+				condition.IfElse(x > 10, es.Term("foo", "bar"),
+					condition.ElseIf(y < 20, es.Exists("fizz")),
+				),
+			),
+	)
+
+	// Then
+	assert.NotNil(t, query)
+	bodyJSON := assert.MarshalWithoutError(t, query)
+	assert.Equal(t, "{\"query\":{\"bool\":{\"filter\":[{\"exists\":{\"field\":\"fizz\"}}]}}}", bodyJSON)
+}
+
+func Test_IfElse_ElseIf_should_return_first_item_when_both_conditions_are_true(t *testing.T) {
+	t.Parallel()
+	// Given
+	x := 15
+	y := 10
+
+	// When
+	query := es.NewQuery(
+		es.Bool().
+			Filter(
+				condition.IfElse(x > 10, es.Term("foo", "bar"),
+					condition.ElseIf(y < 20, es.Exists("fizz")),
+				),
+			),
+	)
+
+	// Then
+	assert.NotNil(t, query)
+	bodyJSON := assert.MarshalWithoutError(t, query)
+	assert.Equal(t, "{\"query\":{\"bool\":{\"filter\":[{\"term\":{\"foo\":{\"value\":\"bar\"}}}]}}}", bodyJSON)
+}
+
+func Test_IfElse_ElseIf_should_return_nil_when_all_conditions_are_false(t *testing.T) {
+	t.Parallel()
+	// Given
+	x := 5
+	y := 25
+
+	// When
+	query := es.NewQuery(
+		es.Bool().
+			Filter(
+				condition.IfElse(x > 10, es.Term("foo", "bar"),
+					condition.ElseIf(y < 20, es.Exists("fizz")),
+				),
+				es.Exists("brandId"),
+			),
+	)
+
+	// Then
+	assert.NotNil(t, query)
+	bodyJSON := assert.MarshalWithoutError(t, query)
+	assert.Equal(t, "{\"query\":{\"bool\":{\"filter\":[{\"exists\":{\"field\":\"brandId\"}}]}}}", bodyJSON)
+}
+
+func Test_IfElse_Else_should_return_default_when_all_conditions_are_false(t *testing.T) {
+	t.Parallel()
+	// Given
+	x := 5
+	y := 25
+
+	// When
+	query := es.NewQuery(
+		es.Bool().
+			Filter(
+				condition.IfElse(x > 10, es.Term("foo", "bar"),
+					condition.ElseIf(y < 20, es.Exists("fizz")),
+					condition.Else(es.Term("default", "value")),
+				),
+			),
+	)
+
+	// Then
+	assert.NotNil(t, query)
+	bodyJSON := assert.MarshalWithoutError(t, query)
+	assert.Equal(t, "{\"query\":{\"bool\":{\"filter\":[{\"term\":{\"default\":{\"value\":\"value\"}}}]}}}", bodyJSON)
+}
+
+func Test_IfElse_Else_should_return_first_item_when_condition_is_true(t *testing.T) {
+	t.Parallel()
+	// Given
+	x := 15
+
+	// When
+	query := es.NewQuery(
+		es.Bool().
+			Filter(
+				condition.IfElse(x > 10, es.Term("foo", "bar"),
+					condition.Else(es.Term("default", "value")),
+				),
+			),
+	)
+
+	// Then
+	assert.NotNil(t, query)
+	bodyJSON := assert.MarshalWithoutError(t, query)
+	assert.Equal(t, "{\"query\":{\"bool\":{\"filter\":[{\"term\":{\"foo\":{\"value\":\"bar\"}}}]}}}", bodyJSON)
+}
+
+func Test_IfElse_Else_should_return_elseIf_item_when_first_false_second_true(t *testing.T) {
+	t.Parallel()
+	// Given
+	x := 5
+	y := 10
+
+	// When
+	query := es.NewQuery(
+		es.Bool().
+			Filter(
+				condition.IfElse(x > 10, es.Term("foo", "bar"),
+					condition.ElseIf(y < 20, es.Exists("fizz")),
+					condition.Else(es.Term("default", "value")),
+				),
+			),
+	)
+
+	// Then
+	assert.NotNil(t, query)
+	bodyJSON := assert.MarshalWithoutError(t, query)
+	assert.Equal(t, "{\"query\":{\"bool\":{\"filter\":[{\"exists\":{\"field\":\"fizz\"}}]}}}", bodyJSON)
+}
+
+func Test_IfElse_multiple_ElseIf_should_return_correct_item(t *testing.T) {
+	t.Parallel()
+	// Given
+	x := 5
+	y := 25
+	z := 3
+
+	// When
+	query := es.NewQuery(
+		es.Bool().
+			Filter(
+				condition.IfElse(x > 10, es.Term("first", "value"),
+					condition.ElseIf(y < 20, es.Term("second", "value")),
+					condition.ElseIf(z < 5, es.Term("third", "value")),
+				),
+			),
+	)
+
+	// Then
+	assert.NotNil(t, query)
+	bodyJSON := assert.MarshalWithoutError(t, query)
+	assert.Equal(t, "{\"query\":{\"bool\":{\"filter\":[{\"term\":{\"third\":{\"value\":\"value\"}}}]}}}", bodyJSON)
+}
+
+func Test_IfElse_should_work_with_slices(t *testing.T) {
+	t.Parallel()
+	// Given
+	cond := true
+
+	// When
+	result := condition.IfElse(cond, es.Array{1, 2, 3})
+
+	// Then
+	assert.NotNil(t, result)
+	bodyJSON := assert.MarshalWithoutError(t, result)
+	assert.Equal(t, "[1,2,3]", bodyJSON)
+}
+
+func Test_IfElse_Else_should_work_with_slices(t *testing.T) {
+	t.Parallel()
+	// Given
+	cond := false
+
+	// When
+	result := condition.IfElse(cond, es.Array{1, 2, 3},
+		condition.Else(es.Array{4, 5, 6}),
+	)
+
+	// Then
+	assert.NotNil(t, result)
+	bodyJSON := assert.MarshalWithoutError(t, result)
+	assert.Equal(t, "[4,5,6]", bodyJSON)
+}