diff --git a/hrp/runner.go b/hrp/runner.go
index 109dd479..1879c441 100644
--- a/hrp/runner.go
+++ b/hrp/runner.go
@@ -490,8 +490,11 @@ func (r *SessionRunner) Start(givenVars map[string]interface{}) (summary *TestCa
 		default:
 			// parse step struct
 			err = r.parseStepStruct(step)
-			if err != nil && r.caseRunner.hrpRunner.failfast {
-				return summary, errors.Wrap(err, "parse step struct failed")
+			if err != nil {
+				log.Error().Err(err).Msg("parse step struct failed")
+				if r.caseRunner.hrpRunner.failfast {
+					return summary, errors.Wrap(err, "parse step struct failed")
+				}
 			}
 
 			stepName := step.Name()
@@ -570,8 +573,8 @@ func (r *SessionRunner) Start(givenVars map[string]interface{}) (summary *TestCa
 func (r *SessionRunner) parseStepStruct(step IStep) error {
 	stepStruct := step.Struct()
 
-	// parse step variables: merges step variables with config variables and session variables
-	// override variables, step variables > session variables (extracted variables from previous steps)
+	// update step variables: merges step variables with config variables and session variables
+	// variables priority: step variables > session variables (extracted variables from previous steps)
 	overrideVars := mergeVariables(stepStruct.Variables, r.sessionVariables)
 	// step variables > testcase config variables
 	overrideVars = mergeVariables(overrideVars, r.caseRunner.Config.Variables)
@@ -600,6 +603,16 @@ func (r *SessionRunner) parseStepStruct(step IStep) error {
 		if !ok {
 			return errors.New("validator type error")
 		}
+		// parse validator check
+		// FIXME: validate with current step's extracted variables
+		// check, err := r.caseRunner.parser.Parse(
+		// 	validator.Check, stepStruct.Variables)
+		// if err != nil {
+		// 	return errors.Wrap(err, "failed to parse validator check")
+		// }
+		// validator.Check, _ = check.(string)
+
+		// parse validator expect
 		validator.Expect, err = r.caseRunner.parser.Parse(
 			validator.Expect, stepStruct.Variables)
 		if err != nil {
diff --git a/hrp/runner_test.go b/hrp/runner_test.go
index 3213c13d..c3bff944 100644
--- a/hrp/runner_test.go
+++ b/hrp/runner_test.go
@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/rs/zerolog/log"
+	"github.com/stretchr/testify/assert"
 
 	"github.com/httprunner/httprunner/v4/hrp/internal/code"
 )
@@ -222,3 +223,41 @@ func TestRunCaseWithRefAPI(t *testing.T) {
 		t.Fatal()
 	}
 }
+
+func TestSessionRunner(t *testing.T) {
+	testcase := TestCase{
+		Config: NewConfig("TestCase").
+			WithVariables(map[string]interface{}{
+				"a":      12.3,
+				"b":      3.45,
+				"varFoo": "${max($a, $b)}",
+			}),
+		TestSteps: []IStep{
+			NewStep("check variables").
+				WithVariables(map[string]interface{}{
+					"a":      12.3,
+					"b":      34.5,
+					"varFoo": "${max($a, $b)}",
+				}).
+				GET("/hello").
+				Validate().
+				AssertEqual("status_code", 200, "check status code"),
+			// AssertEqual("$varFoo", "$b", "check varFoo value"),
+		},
+	}
+
+	caseRunner, _ := NewRunner(t).NewCaseRunner(testcase)
+	sessionRunner := caseRunner.NewSession()
+	step := testcase.TestSteps[0]
+	if !assert.Equal(t, step.Struct().Variables["varFoo"], "${max($a, $b)}") {
+		t.Fatal()
+	}
+
+	err := sessionRunner.parseStepStruct(step)
+	if err != nil {
+		t.Fatal()
+	}
+	if !assert.Equal(t, step.Struct().Variables["varFoo"], 34.5) {
+		t.Fatal()
+	}
+}
diff --git a/hrp/step_mobile_ui.go b/hrp/step_mobile_ui.go
index 75435941..c2629902 100644
--- a/hrp/step_mobile_ui.go
+++ b/hrp/step_mobile_ui.go
@@ -326,7 +326,7 @@ func (s *StepMobile) Sleep(n float64) *StepMobile {
 
 // SleepRandom specify random sleeping seconds after last action
 // params have two different kinds:
-// 1. [min, max] : min and max are float64 time range boudaries
+// 1. [min, max] : min and max are float64 time range boundaries
 // 2. [min1, max1, weight1, min2, max2, weight2, ...] : weight is the probability of the time range
 func (s *StepMobile) SleepRandom(params ...float64) *StepMobile {
 	s.obj().Actions = append(s.obj().Actions, uixt.MobileAction{