Tweak expr record value selection and bool casting

* properly handle casting of false values (empty string)
* add support for record.values.xyz expressions where values is not set

automation/service/workflow.go

@@ -84,7 +84,7 @@ const (
 func Workflow(log *zap.Logger, corredorOpt options.CorredorOpt, opt options.WorkflowOpt) *workflow {
 	return &workflow{
 		log:         log,
-		opt:       opt,
+		opt:         opt,
 		actionlog:   DefaultActionlog,
 		store:       DefaultStore,
 		ac:          DefaultAccessControl,

compose/automation/expr_types.go

@@ -75,9 +75,6 @@ func CastToComposeRecord(val interface{}) (out *types.Record, err error) {
 			val = &types.Record{}
 		}
 
-		if val.Values == nil {
-			val.Values = types.RecordValueSet{}
-		}
 		return val, nil
 	case map[string]interface{}:
 		out = &types.Record{}
@@ -127,10 +124,6 @@ func (t *ComposeRecord) SelectGVal(_ context.Context, k string) (interface{}, er
 			t.value.Values = types.RecordValueSet{}
 		}
 
-		if t.value.Values.Len() == 0 {
-			return nil, nil
-		}
-
 		return &ComposeRecordValues{t.value}, nil
 	}
 
@@ -254,6 +247,15 @@ func (t *ComposeRecordValues) SelectGVal(_ context.Context, k string) (interface
 	return composeRecordValuesGValSelector(t.value, k)
 }
 
+// IsEmpty implements pkg/expr.empty requirements to be able to determine if
+// the value is empty.
+//
+// This is needed cor cases when we are working with empty records, but are trying
+// to access their values.
+func (t *ComposeRecordValues) IsEmpty() bool {
+	return t == nil || t.value == nil || len(t.value.Values) == 0
+}
+
 // Select is field accessor for *types.Record
 //
 // Similar to SelectGVal but returns typed values

compose/types/record_value.go

@@ -7,6 +7,7 @@ import (
 	"strconv"
 	"time"
 
+	"github.com/cortezaproject/corteza-server/pkg/expr"
 	"github.com/cortezaproject/corteza-server/pkg/filter"
 	"github.com/pkg/errors"
 	"github.com/spf13/cast"
@@ -73,7 +74,7 @@ func (v RecordValue) Cast(f *ModuleField) (interface{}, error) {
 		return cast.ToTimeE(v.Value)
 
 	case f.IsBoolean():
-		return cast.ToBoolE(v.Value)
+		return expr.CastToBoolean(v.Value)
 
 	case f.IsNumeric():
 		if f.Options.Precision() == 0 {

pkg/expr/func_generic.go

@@ -7,6 +7,12 @@ import (
 	"github.com/PaesslerAG/gval"
 )
 
+type (
+	empty interface {
+		IsEmpty() bool
+	}
+)
+
 func GenericFunctions() []gval.Language {
 	return []gval.Language{
 		gval.Function("coalesce", coalesce),
@@ -57,6 +63,10 @@ func isEmpty(i interface{}) bool {
 		return true
 	}
 
+	if c, ok := i.(empty); ok {
+		return c.IsEmpty()
+	}
+
 	switch reflect.TypeOf(i).Kind() {
 	case reflect.Slice, reflect.Array, reflect.Map:
 		return reflect.ValueOf(i).Len() == 0