Merge pull request #1219 from nyaruka/less_isnil

Limit use of reflect nil checking

excellent/functions/builtin.go

@@ -1809,7 +1809,7 @@ func JSON(env envs.Environment, value types.XValue) types.XValue {
 //
 // @function format(value)
 func Format(env envs.Environment, value types.XValue) types.XValue {
-	if !utils.IsNil(value) {
+	if !types.IsNil(value) {
 		return types.NewXText(value.Format(env))
 	}
 	return types.XTextEmpty
@@ -2090,7 +2090,7 @@ func IsError(env envs.Environment, value types.XValue) types.XValue {
 // @function count(value)
 func Count(env envs.Environment, value types.XValue) types.XValue {
 	// a nil has count of zero
-	if utils.IsNil(value) {
+	if types.IsNil(value) {
 		return types.XNumberZero
 	}
 

excellent/tools/context_walk.go

@@ -2,7 +2,6 @@ package tools
 
 import (
 	"github.com/nyaruka/goflow/excellent/types"
-	"github.com/nyaruka/goflow/utils"
 )
 
 // ContextWalk traverses the given context invoking the callback for each non-nil value
@@ -21,7 +20,7 @@ func ContextWalkObjects(context *types.XObject, callback func(*types.XObject)) {
 }
 
 func contextWalk(v types.XValue, callback func(types.XValue)) {
-	if utils.IsNil(v) {
+	if types.IsNil(v) {
 		return
 	}
 

excellent/tree.go

@@ -9,7 +9,6 @@ import (
 	"github.com/nyaruka/goflow/excellent/functions"
 	"github.com/nyaruka/goflow/excellent/operators"
 	"github.com/nyaruka/goflow/excellent/types"
-	"github.com/nyaruka/goflow/utils"
 )
 
 type Warnings struct {
@@ -43,7 +42,7 @@ func (x *ContextReference) Evaluate(env envs.Environment, scope *Scope, warnings
 		return types.NewXErrorf("context has no property '%s'", x.name)
 	}
 
-	if !utils.IsNil(value) && value.Deprecated() != "" {
+	if !types.IsNil(value) && value.Deprecated() != "" {
 		warnings.deprecatedContext(value)
 	}
 
@@ -422,7 +421,7 @@ func resolveLookup(env envs.Environment, container types.XValue, lookup types.XV
 		return types.NewXErrorf("%s doesn't support lookups", types.Describe(container))
 	}
 
-	if !utils.IsNil(resolved) && resolved.Deprecated() != "" {
+	if !types.IsNil(resolved) && resolved.Deprecated() != "" {
 		warnings.deprecatedContext(resolved)
 	}
 

excellent/types/array.go

@@ -139,7 +139,7 @@ var XArrayEmpty = NewXArray()
 
 // ToXArray converts the given value to an array
 func ToXArray(env envs.Environment, x XValue) (*XArray, *XError) {
-	if utils.IsNil(x) {
+	if IsNil(x) {
 		return XArrayEmpty, nil
 	}
 	if IsXError(x) {

excellent/types/base.go

@@ -6,7 +6,6 @@ import (
 	"reflect"
 
 	"github.com/nyaruka/goflow/envs"
-	"github.com/nyaruka/goflow/utils"
 )
 
 // XValue is the base interface of all excellent types
@@ -54,9 +53,9 @@ type XComparable interface {
 // specifically means text(x) == text(y)
 func Equals(x1 XValue, x2 XValue) bool {
 	// nil == nil
-	if utils.IsNil(x1) && utils.IsNil(x2) {
+	if IsNil(x1) && IsNil(x2) {
 		return true
-	} else if utils.IsNil(x1) || utils.IsNil(x2) {
+	} else if IsNil(x1) || IsNil(x2) {
 		return false
 	}
 
@@ -71,11 +70,11 @@ func Equals(x1 XValue, x2 XValue) bool {
 // Compare compares two given values
 func Compare(x1 XValue, x2 XValue) int {
 	// nil == nil
-	if utils.IsNil(x1) && utils.IsNil(x2) {
+	if IsNil(x1) && IsNil(x2) {
 		return 0
-	} else if utils.IsNil(x1) {
+	} else if IsNil(x1) {
 		return -1
-	} else if utils.IsNil(x2) {
+	} else if IsNil(x2) {
 		return 1
 	}
 
@@ -99,44 +98,50 @@ func SameType(x1 XValue, x2 XValue) bool {
 
 // Describe returns a representation of the given value for use in error messages
 func Describe(x XValue) string {
-	if utils.IsNil(x) {
+	if IsNil(x) {
 		return "null"
 	}
 	return x.Describe()
 }
 
 // Truthy determines truthiness for the given value
 func Truthy(x XValue) bool {
-	if utils.IsNil(x) {
+	if IsNil(x) {
 		return false
 	}
 	return x.Truthy()
 }
 
 // Render returns the canonical text representation
 func Render(x XValue) string {
-	if utils.IsNil(x) {
+	if IsNil(x) {
 		return ""
 	}
 	return x.Render()
 }
 
 // Format returns the pretty text representation
 func Format(env envs.Environment, x XValue) string {
-	if utils.IsNil(x) {
+	if IsNil(x) {
 		return ""
 	}
 	return x.Format(env)
 }
 
 // String returns a representation of the given value for use in debugging
 func String(x XValue) string {
-	if utils.IsNil(x) {
+	if IsNil(x) {
 		return "nil"
 	}
 	return x.String()
 }
 
+// IsNil returns whether the given value is nil... because of golang's love of autoboxing nil pointers into non-nil
+// interfaces, we need to check if interface itself is nil or the underlying pointer is nil.
+func IsNil(x XValue) bool {
+	return x == nil || reflect.ValueOf(x).IsNil()
+}
+
 // baseValue is shared by all X types
 type baseValue struct {
 	deprecated string

excellent/types/boolean.go

@@ -5,7 +5,6 @@ import (
 
 	"github.com/nyaruka/gocommon/jsonx"
 	"github.com/nyaruka/goflow/envs"
-	"github.com/nyaruka/goflow/utils"
 )
 
 // XBoolean is a boolean `true` or `false`.
@@ -90,7 +89,7 @@ var _ XValue = XBooleanFalse
 
 // ToXBoolean converts the given value to a boolean
 func ToXBoolean(x XValue) (*XBoolean, *XError) {
-	if utils.IsNil(x) {
+	if IsNil(x) {
 		return XBooleanFalse, nil
 	}
 	if IsXError(x) {

excellent/types/date.go

@@ -6,7 +6,6 @@ import (
 	"github.com/nyaruka/gocommon/dates"
 	"github.com/nyaruka/gocommon/jsonx"
 	"github.com/nyaruka/goflow/envs"
-	"github.com/nyaruka/goflow/utils"
 )
 
 // XDate is a Gregorian calendar date value.
@@ -82,7 +81,7 @@ var _ XValue = XDateZero
 
 // ToXDate converts the given value to a time or returns an error if that isn't possible
 func ToXDate(env envs.Environment, x XValue) (*XDate, *XError) {
-	if !utils.IsNil(x) {
+	if !IsNil(x) {
 		switch typed := x.(type) {
 		case *XError:
 			return XDateZero, typed

excellent/types/datetime.go

@@ -7,7 +7,6 @@ import (
 	"github.com/nyaruka/gocommon/dates"
 	"github.com/nyaruka/gocommon/jsonx"
 	"github.com/nyaruka/goflow/envs"
-	"github.com/nyaruka/goflow/utils"
 )
 
 // XDateTime is a datetime value.
@@ -135,7 +134,7 @@ func ToXDateTimeWithTimeFill(env envs.Environment, x XValue) (*XDateTime, *XErro
 
 // converts the given value to a time or returns an error if that isn't possible
 func toXDateTime(env envs.Environment, x XValue, fillTime bool) (*XDateTime, *XError) {
-	if !utils.IsNil(x) {
+	if !IsNil(x) {
 		switch typed := x.(type) {
 		case *XError:
 			return XDateTimeZero, typed

excellent/types/json.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/buger/jsonparser"
 	"github.com/nyaruka/gocommon/jsonx"
-	"github.com/nyaruka/goflow/utils"
 	"github.com/pkg/errors"
 	"github.com/shopspring/decimal"
 )
@@ -82,7 +81,7 @@ func jsonToArray(data []byte) *XArray {
 
 // ToXJSON converts the given value to a JSON string
 func ToXJSON(x XValue) (*XText, *XError) {
-	if utils.IsNil(x) {
+	if IsNil(x) {
 		return NewXText(`null`), nil
 	}
 	if IsXError(x) {

excellent/types/number.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/nyaruka/gocommon/jsonx"
 	"github.com/nyaruka/goflow/envs"
-	"github.com/nyaruka/goflow/utils"
 	"github.com/pkg/errors"
 	"github.com/shopspring/decimal"
 )
@@ -152,7 +151,7 @@ func newXNumberFromString(s string) (*XNumber, error) {
 
 // ToXNumber converts the given value to a number or returns an error if that isn't possible
 func ToXNumber(env envs.Environment, x XValue) (*XNumber, *XError) {
-	if !utils.IsNil(x) {
+	if !IsNil(x) {
 		switch typed := x.(type) {
 		case *XError:
 			return XNumberZero, typed

excellent/types/object.go

@@ -237,7 +237,7 @@ var _ json.Marshaler = (*XObject)(nil)
 
 // ToXObject converts the given value to an object
 func ToXObject(env envs.Environment, x XValue) (*XObject, *XError) {
-	if utils.IsNil(x) {
+	if IsNil(x) {
 		return XObjectEmpty, nil
 	}
 	if IsXError(x) {

excellent/types/text.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/nyaruka/gocommon/jsonx"
 	"github.com/nyaruka/goflow/envs"
-	"github.com/nyaruka/goflow/utils"
 )
 
 // XText is a string of characters.
@@ -89,7 +88,7 @@ var _ XValue = XTextEmpty
 
 // ToXText converts the given value to a string
 func ToXText(env envs.Environment, x XValue) (*XText, *XError) {
-	if utils.IsNil(x) {
+	if IsNil(x) {
 		return XTextEmpty, nil
 	}
 	if IsXError(x) {

excellent/types/time.go

@@ -6,7 +6,6 @@ import (
 	"github.com/nyaruka/gocommon/dates"
 	"github.com/nyaruka/gocommon/jsonx"
 	"github.com/nyaruka/goflow/envs"
-	"github.com/nyaruka/goflow/utils"
 )
 
 // XTime is a time of day.
@@ -88,7 +87,7 @@ var _ XValue = XTimeZero
 
 // ToXTime converts the given value to a time or returns an error if that isn't possible
 func ToXTime(env envs.Environment, x XValue) (*XTime, *XError) {
-	if !utils.IsNil(x) {
+	if !IsNil(x) {
 		switch typed := x.(type) {
 		case *XError:
 			return XTimeZero, typed

flows/definition/legacy/expressions/migrate_test.go

@@ -17,7 +17,6 @@ import (
 	"github.com/nyaruka/goflow/excellent/types"
 	"github.com/nyaruka/goflow/flows/definition/legacy/expressions"
 	"github.com/nyaruka/goflow/test"
-	"github.com/nyaruka/goflow/utils"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -277,7 +276,7 @@ func (v legacyVariables) Context(env envs.Environment) *types.XObject {
 }
 
 func toXType(env envs.Environment, val any) types.XValue {
-	if utils.IsNil(val) {
+	if val == nil {
 		return nil
 	}
 

flows/expressions.go

@@ -1,11 +1,11 @@
 package flows
 
 import (
+	"reflect"
 	"strconv"
 
 	"github.com/nyaruka/goflow/envs"
 	"github.com/nyaruka/goflow/excellent/types"
-	"github.com/nyaruka/goflow/utils"
 )
 
 // Contextable is an object that can accessed in expressions as a object with properties
@@ -15,12 +15,15 @@ type Contextable interface {
 
 // Context generates a lazy object for use in expressions
 func Context(env envs.Environment, contextable Contextable) types.XValue {
-	if !utils.IsNil(contextable) {
-		return types.NewXLazyObject(func() map[string]types.XValue {
-			return contextable.Context(env)
-		})
+	// we allow passing nil pointers which will become non-nil Contextables
+	if contextable == nil || reflect.ValueOf(contextable).IsNil() {
+		return nil
 	}
-	return nil
+
+	return types.NewXLazyObject(func() map[string]types.XValue {
+		return contextable.Context(env)
+	})
+
 }
 
 // ContextFunc generates a lazy object for use in expressions

flows/field.go

@@ -8,7 +8,6 @@ import (
 	"github.com/nyaruka/goflow/assets"
 	"github.com/nyaruka/goflow/envs"
 	"github.com/nyaruka/goflow/excellent/types"
-	"github.com/nyaruka/goflow/utils"
 )
 
 // Field represents a contact field
@@ -284,7 +283,7 @@ func (f FieldValues) Context(env envs.Environment) map[string]types.XValue {
 		val := v.ToXValue(env)
 		entries[string(k)] = val
 
-		if !utils.IsNil(val) {
+		if val != nil {
 			lines = append(lines, fmt.Sprintf("%s: %s", v.field.Name(), types.Render(val)))
 		}
 	}

flows/routers/base.go

@@ -53,7 +53,7 @@ func (r *baseRouter) Categories() []flows.Category { return r.categories }
 
 // AllowTimeout returns whether this router can be resumed at with a timeout
 func (r *baseRouter) AllowTimeout() bool {
-	return r.wait != nil && !utils.IsNil(r.wait.Timeout())
+	return r.wait != nil && r.wait.Timeout() != nil
 }
 
 // ResultName returns the name which the result of this router should be saved as (if any)

flows/routers/waits/base.go

@@ -48,7 +48,12 @@ func newBaseWait(typeName string, timeout *Timeout) baseWait {
 func (w *baseWait) Type() string { return w.type_ }
 
 // Timeout returns the timeout of this wait or nil if no timeout is set
-func (w *baseWait) Timeout() flows.Timeout { return w.timeout }
+func (w *baseWait) Timeout() flows.Timeout {
+	if w.timeout == nil {
+		return nil
+	}
+	return w.timeout
+}
 
 func (w *baseWait) expiresOn(run flows.Run) *time.Time {
 	expiresAfterMins := run.Flow().ExpireAfterMinutes()

flows/runs/run.go

@@ -216,8 +216,13 @@ func (r *run) RootContext(env envs.Environment) map[string]types.XValue {
 		}
 	}
 
-	var child = newRelatedRunContext(r.Session().GetCurrentChild(r))
-	var parent = newRelatedRunContext(r.Parent())
+	var child, parent *relatedRunContext
+	if r.Session().GetCurrentChild(r) != nil {
+		child = newRelatedRunContext(r.Session().GetCurrentChild(r))
+	}
+	if r.Parent() != nil {
+		parent = newRelatedRunContext(r.Parent())
+	}
 
 	_, n, _ := r.PathLocation()
 	if n != nil {