test: add tests for object pkg

internal/evaluator/evaluator.go

@@ -28,26 +28,26 @@ func (e *evaluator) Eval(node ast.Node) (object.Object, error) {
 		return object.NIL, ErrEmptyNodeInput
 	}
 
-	switch node.(type) {
+	switch node := node.(type) {
 	// evaluate the program
 	case *ast.Program:
-		return e.evalStatements(node.(*ast.Program).Statements)
+		return e.evalStatements(node.Statements)
 	// evaluate statements
 	case *ast.ExpressionStatement:
-		return e.Eval(node.(*ast.ExpressionStatement).Expression)
+		return e.Eval(node.Expression)
 	case *ast.BlockStatement:
-		return e.evalStatements(node.(*ast.BlockStatement).Statements)
+		return e.evalStatements(node.Statements)
 	// evaluate expressions
 	case *ast.IntegerExpression:
-		return object.NewInteger(node.(*ast.IntegerExpression).Value), nil
+		return object.NewInteger(node.Value), nil
 	case *ast.BooleanExpression:
-		return booleanConv(node.(*ast.BooleanExpression).Value), nil
+		return booleanConv(node.Value), nil
 	case *ast.IfExpression:
-		return e.evalIfExpression(node.(*ast.IfExpression))
+		return e.evalIfExpression(node)
 	case *ast.PrefixExpression:
-		return e.evalPrefixExpression(node.(*ast.PrefixExpression))
+		return e.evalPrefixExpression(node)
 	case *ast.InfixExpression:
-		return e.evalInfixExpression(node.(*ast.InfixExpression))
+		return e.evalInfixExpression(node)
 	}
 
 	// no match, unexpected path

internal/object/object.go

@@ -2,10 +2,17 @@ package object
 
 import "strconv"
 
-const (
-	INTEGER_OBJ = "INTEGER"
-	BOOLEAN_OBJ = "BOOLEAN"
-	NIL_OBJ     = "NIL"
+// interface compliance check
+var _ Object = (*Integer)(nil)
+var _ Object = (*Boolean)(nil)
+var _ Object = (*Nil)(nil)
+
+type ObjectType string
+
+var (
+	INTEGER_OBJ = ObjectType("INTEGER")
+	BOOLEAN_OBJ = ObjectType("BOOLEAN")
+	NIL_OBJ     = ObjectType("NIL")
 )
 
 // boolean literal objects
@@ -15,13 +22,6 @@ var (
 	NIL   = NewNil()
 )
 
-// interface compliance check
-var _ Object = (*Integer)(nil)
-var _ Object = (*Boolean)(nil)
-var _ Object = (*Nil)(nil)
-
-type ObjectType string
-
 type Object interface {
 	Type() ObjectType
 	Inspect() string
@@ -70,7 +70,7 @@ func (b *Boolean) Inspect() string {
 }
 
 func (b *Boolean) IsTruthy() bool {
-	return b.Value == true
+	return b.Value
 }
 
 // Nil represents the absence of any value

internal/object/object_test.go

@@ -2,9 +2,79 @@ package object_test
 
 import (
 	. "github.com/onsi/ginkgo/v2"
-	_ "github.com/onsi/gomega"
+	. "github.com/onsi/gomega"
+
+	"github.com/aden-q/monkey/internal/object"
 )
 
 var _ = Describe("Object", func() {
+	Describe("Integer", func() {
+		Context("integer object", func() {
+			It("truthy integer object", func() {
+				var val int64 = 5
+
+				expectedIntegerObj := &object.Integer{
+					Value: val,
+				}
+				obj := object.NewInteger(val)
+
+				Expect(obj).To(Equal(expectedIntegerObj))
+				Expect(obj.Inspect()).To(Equal("5"))
+				Expect(obj.Type()).To(Equal(object.INTEGER_OBJ))
+				Expect(obj.IsTruthy()).To(Equal(true))
+			})
+
+			It("false integer object", func() {
+				var val int64 = 0
+
+				expectedIntegerObj := &object.Integer{
+					Value: val,
+				}
+				obj := object.NewInteger(val)
+
+				Expect(obj).To(Equal(expectedIntegerObj))
+				Expect(obj.Inspect()).To(Equal("0"))
+				Expect(obj.Type()).To(Equal(object.INTEGER_OBJ))
+				Expect(obj.IsTruthy()).To(Equal(false))
+			})
+		})
+	})
+
+	Describe("Boolean", func() {
+		It("truthy boolean object", func() {
+			var val bool = true
+
+			expectedBooleanObj := object.TRUE
+			obj := object.NewBoolean(val)
+
+			Expect(obj).To(Equal(expectedBooleanObj))
+			Expect(obj.Inspect()).To(Equal("true"))
+			Expect(obj.Type()).To(Equal(object.BOOLEAN_OBJ))
+			Expect(obj.IsTruthy()).To(Equal(true))
+		})
+
+		It("false boolean object", func() {
+			var val bool = false
+
+			expectedBooleanObj := object.FALSE
+			obj := object.NewBoolean(val)
+
+			Expect(obj).To(Equal(expectedBooleanObj))
+			Expect(obj.Inspect()).To(Equal("false"))
+			Expect(obj.Type()).To(Equal(object.BOOLEAN_OBJ))
+			Expect(obj.IsTruthy()).To(Equal(false))
+		})
+	})
+
+	Describe("Boolean", func() {
+		It("false nil object", func() {
+			expectedNilObj := object.NIL
+			obj := object.NewNil()
 
+			Expect(obj).To(Equal(expectedNilObj))
+			Expect(obj.Inspect()).To(Equal("nil"))
+			Expect(obj.Type()).To(Equal(object.NIL_OBJ))
+			Expect(obj.IsTruthy()).To(Equal(false))
+		})
+	})
 })