test: add test cases

pkg/utils/ifelse/ifelse.go

@@ -1,34 +1,84 @@
 package ifelse
 
+type branch[T any] struct {
+	cond bool
+	fn   func() T
+}
+
 type ifExpr[T any] struct {
-	condition bool
+	cond bool
 }
 
 type thenExpr[T any] struct {
-	condition  bool
-	consequent T
+	branches []branch[T]
 }
 
-// 示例：
+type elseIfExpr[T any] struct {
+	branches []branch[T]
+	cond     bool
+}
+
+// 用法示例：
 //
-//	result := ifelse.If[T](condition).Then(consequent).Else(alternative)
+//	result := ifelse.If[string](age < 18).Then("child").
+//	  ElseIf(age < 60).Then("adult").
+//	  ElseIf(age < 120).Then("senior").
+//	  Else("invalid")
 func If[T any](condition bool) *ifExpr[T] {
-	return &ifExpr[T]{
-		condition: condition,
-	}
+	return &ifExpr[T]{cond: condition}
 }
 
 func (e *ifExpr[T]) Then(consequent T) *thenExpr[T] {
 	return &thenExpr[T]{
-		condition:  e.condition,
-		consequent: consequent,
+		branches: []branch[T]{
+			{cond: e.cond, fn: func() T { return consequent }},
+		},
+	}
+}
+
+func (e *ifExpr[T]) ThenFunc(consequent func() T) *thenExpr[T] {
+	return &thenExpr[T]{
+		branches: []branch[T]{
+			{cond: e.cond, fn: consequent},
+		},
+	}
+}
+
+func (e *thenExpr[T]) ElseIf(condition bool) *elseIfExpr[T] {
+	return &elseIfExpr[T]{
+		branches: e.branches,
+		cond:     condition,
+	}
+}
+
+func (e *elseIfExpr[T]) Then(alternative T) *thenExpr[T] {
+	branch := branch[T]{cond: e.cond, fn: func() T { return alternative }}
+	return &thenExpr[T]{
+		branches: append(e.branches, branch),
+	}
+}
+
+func (e *elseIfExpr[T]) ThenFunc(alternativeFunc func() T) *thenExpr[T] {
+	branch := branch[T]{cond: e.cond, fn: alternativeFunc}
+	return &thenExpr[T]{
+		branches: append(e.branches, branch),
 	}
 }
 
 func (e *thenExpr[T]) Else(alternative T) T {
-	if e.condition {
-		return e.consequent
+	for _, b := range e.branches {
+		if b.cond {
+			return b.fn()
+		}
 	}
-
 	return alternative
 }
+
+func (e *thenExpr[T]) ElseFunc(alternativeFunc func() T) T {
+	for _, b := range e.branches {
+		if b.cond {
+			return b.fn()
+		}
+	}
+	return alternativeFunc()
+}

pkg/utils/ifelse/ifelse_test.go

@@ -0,0 +1,196 @@
+package ifelse_test
+
+import (
+	"testing"
+
+	"github.com/certimate-go/certimate/pkg/utils/ifelse"
+)
+
+func TestIfTrue(t *testing.T) {
+	result := ifelse.If[string](true).
+		Then("true branch").
+		Else("false branch")
+
+	if result != "true branch" {
+		t.Errorf("Expected 'true branch', got '%s'", result)
+	}
+}
+
+func TestIfFalse(t *testing.T) {
+	result := ifelse.If[string](false).
+		Then("true branch").
+		Else("false branch")
+
+	if result != "false branch" {
+		t.Errorf("Expected 'false branch', got '%s'", result)
+	}
+}
+
+func TestElseIfFirstMatch(t *testing.T) {
+	result := ifelse.If[string](false).
+		Then("should not run").
+		ElseIf(true).
+		Then("elseif branch").
+		Else("should not run")
+
+	if result != "elseif branch" {
+		t.Errorf("Expected 'elseif branch', got '%s'", result)
+	}
+}
+
+func TestElseIfSecondMatch(t *testing.T) {
+	result := ifelse.If[string](false).
+		Then("should not run").
+		ElseIf(false).
+		Then("should not run").
+		ElseIf(true).
+		Then("second elseif").
+		Else("should not run")
+
+	if result != "second elseif" {
+		t.Errorf("Expected 'second elseif', got '%s'", result)
+	}
+}
+
+func TestMultipleConditions(t *testing.T) {
+	result := ifelse.If[string](1 > 2).
+		Then("impossible").
+		ElseIf(2+2 == 5).
+		Then("false math").
+		ElseIf(3*3 == 9).
+		Then("correct math").
+		Else("fallback")
+
+	if result != "correct math" {
+		t.Errorf("Expected 'correct math', got '%s'", result)
+	}
+}
+
+func TestAllConditionsFalse(t *testing.T) {
+	result := ifelse.If[int](false).
+		Then(1).
+		ElseIf(false).
+		Then(2).
+		ElseIf(false).
+		Then(3).
+		Else(99)
+
+	if result != 99 {
+		t.Errorf("Expected 99, got %d", result)
+	}
+}
+
+func TestLazyEvaluationThen(t *testing.T) {
+	called := []string{}
+
+	result := ifelse.If[string](true).
+		ThenFunc(func() string {
+			called = append(called, "then")
+			return "then"
+		}).
+		ElseIf(true).
+		ThenFunc(func() string {
+			called = append(called, "elseif")
+			return "elseif"
+		}).
+		ElseFunc(func() string {
+			called = append(called, "else")
+			return "else"
+		})
+
+	// 验证结果和调用情况
+	if result != "then" {
+		t.Errorf("Expected 'then', got '%s'", result)
+	}
+
+	if len(called) != 1 || called[0] != "then" {
+		t.Errorf("Expected only 'then' called, got %v", called)
+	}
+}
+
+func TestLazyEvaluationElseIf(t *testing.T) {
+	called := []string{}
+
+	result := ifelse.If[string](false).
+		ThenFunc(func() string {
+			called = append(called, "then")
+			return "then"
+		}).
+		ElseIf(true).
+		ThenFunc(func() string {
+			called = append(called, "elseif")
+			return "elseif"
+		}).
+		ElseFunc(func() string {
+			called = append(called, "else")
+			return "else"
+		})
+
+	// 验证结果和调用情况
+	if result != "elseif" {
+		t.Errorf("Expected 'elseif', got '%s'", result)
+	}
+
+	if len(called) != 1 || called[0] != "elseif" {
+		t.Errorf("Expected only 'elseif' called, got %v", called)
+	}
+}
+
+func TestLazyEvaluationElse(t *testing.T) {
+	called := []string{}
+
+	result := ifelse.If[string](false).
+		ThenFunc(func() string {
+			called = append(called, "then")
+			return "then"
+		}).
+		ElseIf(false).
+		ThenFunc(func() string {
+			called = append(called, "elseif")
+			return "elseif"
+		}).
+		ElseFunc(func() string {
+			called = append(called, "else")
+			return "else"
+		})
+
+	// 验证结果和调用情况
+	if result != "else" {
+		t.Errorf("Expected 'else', got '%s'", result)
+	}
+
+	if len(called) != 1 || called[0] != "else" {
+		t.Errorf("Expected only 'else' called, got %v", called)
+	}
+}
+
+func TestMixedValueAndFunc(t *testing.T) {
+	result := ifelse.If[int](false).
+		Then(0).
+		ElseIf(false).
+		ThenFunc(func() int {
+			return 1
+		}).
+		ElseIf(true).
+		Then(2).
+		Else(3)
+
+	if result != 2 {
+		t.Errorf("Expected 2, got %d", result)
+	}
+}
+
+func TestComplexNumericLogic(t *testing.T) {
+	x := 15
+	result := ifelse.If[string](x < 10).
+		Then("single digit").
+		ElseIf(x < 20).
+		Then("teens").
+		ElseIf(x < 30).
+		Then("twenties").
+		Else("older")
+
+	if result != "teens" {
+		t.Errorf("Expected 'teens', got '%s'", result)
+	}
+}