fix: keep env evaluator in sync

Co-Authored-By: Codet (GPT-5) <codet@commitgo.dev>

act/runner/run_context.go

@@ -78,13 +78,20 @@ func (rc *RunContext) String() string {
 
 // GetEnv returns the env for the context
 func (rc *RunContext) GetEnv() map[string]string {
+	baseEnv := map[string]string{}
+	if rc.Run != nil && rc.Run.Workflow != nil && rc.Config != nil {
+		job := rc.Run.Job()
+		if job != nil {
+			baseEnv = mergeMaps(rc.Run.Workflow.Env, job.Environment(), rc.Config.Env)
+		}
+	}
+
 	if rc.Env == nil {
 		rc.Env = map[string]string{}
-		if rc.Run != nil && rc.Run.Workflow != nil && rc.Config != nil {
-			job := rc.Run.Job()
-			if job != nil {
-				rc.Env = mergeMaps(rc.Run.Workflow.Env, job.Environment(), rc.Config.Env)
-			}
+	}
+	for k, v := range baseEnv {
+		if _, ok := rc.Env[k]; !ok {
+			rc.Env[k] = v
 		}
 	}
 	rc.Env["ACT"] = "true"

act/runner/run_context_test.go

@@ -572,6 +572,10 @@ if: false`, ""),
 }
 
 func TestRunContextGetEnv(t *testing.T) {
+	var jobEnv yaml.Node
+	err := jobEnv.Encode(map[string]string{"JOB_ONLY": "job-value"})
+	assert.NoError(t, err) //nolint:testifylint // pre-existing issue from nektos/act
+
 	tests := []struct {
 		description string
 		rc          *RunContext
@@ -612,6 +616,26 @@ func TestRunContextGetEnv(t *testing.T) {
 			targetEnv: "OVERWRITTEN",
 			want:      "false",
 		},
+		{
+			description: "Pre-populated run context env should still include job env",
+			rc: &RunContext{
+				Config: &Config{},
+				Env: map[string]string{
+					"RUNTIME_ONLY": "true",
+				},
+				Run: &model.Run{
+					JobID: "test",
+					Workflow: &model.Workflow{
+						Jobs: map[string]*model.Job{"test": {
+							Name: "test",
+							Env:  jobEnv,
+						}},
+					},
+				},
+			},
+			targetEnv: "JOB_ONLY",
+			want:      "job-value",
+		},
 	}
 
 	for _, test := range tests {
@@ -622,6 +646,37 @@ func TestRunContextGetEnv(t *testing.T) {
 	}
 }
 
+func TestRunContextGetEnvKeepsExpressionEvaluatorEnvCurrent(t *testing.T) {
+	var jobEnv yaml.Node
+	err := jobEnv.Encode(map[string]string{"JOB_ONLY": "job-value"})
+	assert.NoError(t, err) //nolint:testifylint // pre-existing issue from nektos/act
+
+	rc := &RunContext{
+		Config: &Config{},
+		Env: map[string]string{
+			"RUNTIME_ONLY": "true",
+		},
+		Run: &model.Run{
+			JobID: "test",
+			Workflow: &model.Workflow{
+				Jobs: map[string]*model.Job{"test": {
+					Name: "test",
+					Env:  jobEnv,
+				}},
+			},
+		},
+	}
+
+	rc.ExprEval = rc.NewExpressionEvaluator(context.Background())
+	rc.GetEnv()
+	rc.setEnv(context.Background(), map[string]string{"name": "STEP_TIMEOUT"}, "0")
+
+	got, evalErr := rc.ExprEval.evaluate(context.Background(), "env.STEP_TIMEOUT", exprparser.DefaultStatusCheckNone)
+	assert.NoError(t, evalErr) //nolint:testifylint // pre-existing issue from nektos/act
+	assert.EqualValues(t, "0", got)
+	assert.EqualValues(t, "job-value", rc.Env["JOB_ONLY"]) //nolint:testifylint // pre-existing issue from nektos/act
+}
+
 func Test_createSimpleContainerName(t *testing.T) {
 	tests := []struct {
 		parts []string

act/runner/step_test.go

@@ -120,6 +120,10 @@ func TestSetupEnv(t *testing.T) {
 	cm := &containerMock{}
 	sm := &stepMock{}
 
+	var jobEnv yaml.Node
+	err := jobEnv.Encode(map[string]string{"JOB_KEY": "jobvalue"})
+	assert.NoError(t, err) //nolint:testifylint // pre-existing issue from nektos/act
+
 	rc := &RunContext{
 		Config: &Config{
 			Env: map[string]string{
@@ -131,9 +135,7 @@ func TestSetupEnv(t *testing.T) {
 			Workflow: &model.Workflow{
 				Jobs: map[string]*model.Job{
 					"1": {
-						Env: yaml.Node{
-							Value: "JOB_KEY: jobvalue",
-						},
+						Env: jobEnv,
 					},
 				},
 			},
@@ -155,7 +157,7 @@ func TestSetupEnv(t *testing.T) {
 	sm.On("getStepModel").Return(step)
 	sm.On("getEnv").Return(&env)
 
-	err := setupEnv(context.Background(), sm)
+	err = setupEnv(context.Background(), sm)
 	assert.Nil(t, err) //nolint:testifylint // pre-existing issue from nektos/act
 
 	// These are commit or system specific
@@ -191,6 +193,7 @@ func TestSetupEnv(t *testing.T) {
 		"GITHUB_SERVER_URL":        "https://",
 		"GITHUB_WORKFLOW":          "",
 		"INPUT_STEP_WITH":          "with-value",
+		"JOB_KEY":                  "jobvalue",
 		"RC_KEY":                   "rcvalue",
 		"RUNNER_PERFLOG":           "/dev/null",
 		"RUNNER_TRACKING_ID":       "",