Update cel-go to v0.21.0

vendor/github.com/google/cel-go/cel/env.go

@@ -44,6 +44,9 @@ type Ast struct {
 
 // NativeRep converts the AST to a Go-native representation.
 func (ast *Ast) NativeRep() *celast.AST {
+	if ast == nil {
+		return nil
+	}
 	return ast.impl
 }
 
@@ -55,16 +58,13 @@ func (ast *Ast) Expr() *exprpb.Expr {
 	if ast == nil {
 		return nil
 	}
-	pbExpr, _ := celast.ExprToProto(ast.impl.Expr())
+	pbExpr, _ := celast.ExprToProto(ast.NativeRep().Expr())
 	return pbExpr
 }
 
 // IsChecked returns whether the Ast value has been successfully type-checked.
 func (ast *Ast) IsChecked() bool {
-	if ast == nil {
-		return false
-	}
-	return ast.impl.IsChecked()
+	return ast.NativeRep().IsChecked()
 }
 
 // SourceInfo returns character offset and newline position information about expression elements.
@@ -72,7 +72,7 @@ func (ast *Ast) SourceInfo() *exprpb.SourceInfo {
 	if ast == nil {
 		return nil
 	}
-	pbInfo, _ := celast.SourceInfoToProto(ast.impl.SourceInfo())
+	pbInfo, _ := celast.SourceInfoToProto(ast.NativeRep().SourceInfo())
 	return pbInfo
 }
 
@@ -95,7 +95,7 @@ func (ast *Ast) OutputType() *Type {
 	if ast == nil {
 		return types.ErrorType
 	}
-	return ast.impl.GetType(ast.impl.Expr().ID())
+	return ast.NativeRep().GetType(ast.NativeRep().Expr().ID())
 }
 
 // Source returns a view of the input used to create the Ast. This source may be complete or
@@ -218,12 +218,12 @@ func (e *Env) Check(ast *Ast) (*Ast, *Issues) {
 	if err != nil {
 		errs := common.NewErrors(ast.Source())
 		errs.ReportError(common.NoLocation, err.Error())
-		return nil, NewIssuesWithSourceInfo(errs, ast.impl.SourceInfo())
+		return nil, NewIssuesWithSourceInfo(errs, ast.NativeRep().SourceInfo())
 	}
 
-	checked, errs := checker.Check(ast.impl, ast.Source(), chk)
+	checked, errs := checker.Check(ast.NativeRep(), ast.Source(), chk)
 	if len(errs.GetErrors()) > 0 {
-		return nil, NewIssuesWithSourceInfo(errs, ast.impl.SourceInfo())
+		return nil, NewIssuesWithSourceInfo(errs, ast.NativeRep().SourceInfo())
 	}
 	// Manually create the Ast to ensure that the Ast source information (which may be more
 	// detailed than the information provided by Check), is returned to the caller.
@@ -244,7 +244,7 @@ func (e *Env) Check(ast *Ast) (*Ast, *Issues) {
 		}
 	}
 	// Apply additional validators on the type-checked result.
-	iss := NewIssuesWithSourceInfo(errs, ast.impl.SourceInfo())
+	iss := NewIssuesWithSourceInfo(errs, ast.NativeRep().SourceInfo())
 	for _, v := range e.validators {
 		v.Validate(e, vConfig, checked, iss)
 	}
@@ -309,17 +309,13 @@ func (e *Env) Extend(opts ...EnvOption) (*Env, error) {
 	copy(chkOptsCopy, e.chkOpts)
 
 	// Copy the declarations if needed.
-	varsCopy := []*decls.VariableDecl{}
 	if chk != nil {
 		// If the type-checker has already been instantiated, then the e.declarations have been
 		// validated within the chk instance.
 		chkOptsCopy = append(chkOptsCopy, checker.ValidatedDeclarations(chk))
-	} else {
-		// If the type-checker has not been instantiated, ensure the unvalidated declarations are
-		// provided to the extended Env instance.
-		varsCopy = make([]*decls.VariableDecl, len(e.variables))
-		copy(varsCopy, e.variables)
 	}
+	varsCopy := make([]*decls.VariableDecl, len(e.variables))
+	copy(varsCopy, e.variables)
 
 	// Copy macros and program options
 	macsCopy := make([]parser.Macro, len(e.macros))
@@ -416,6 +412,17 @@ func (e *Env) Libraries() []string {
 	return libraries
 }
 
+// HasFunction returns whether a specific function has been configured in the environment
+func (e *Env) HasFunction(functionName string) bool {
+	_, ok := e.functions[functionName]
+	return ok
+}
+
+// Functions returns map of Functions, keyed by function name, that have been configured in the environment.
+func (e *Env) Functions() map[string]*decls.FunctionDecl {
+	return e.functions
+}
+
 // HasValidator returns whether a specific ASTValidator has been configured in the environment.
 func (e *Env) HasValidator(name string) bool {
 	for _, v := range e.validators {
@@ -753,10 +760,10 @@ func (i *Issues) Append(other *Issues) *Issues {
 	if i == nil {
 		return other
 	}
-	if other == nil {
+	if other == nil || i == other {
 		return i
 	}
-	return NewIssues(i.errs.Append(other.errs.GetErrors()))
+	return NewIssuesWithSourceInfo(i.errs.Append(other.errs.GetErrors()), i.info)
 }
 
 // String converts the issues to a suitable display string.
@@ -790,7 +797,7 @@ type interopCELTypeProvider struct {
 
 // FindStructType returns a types.Type instance for the given fully-qualified typeName if one exists.
 //
-// This method proxies to the underyling ref.TypeProvider's FindType method and converts protobuf type
+// This method proxies to the underlying ref.TypeProvider's FindType method and converts protobuf type
 // into a native type representation. If the conversion fails, the type is listed as not found.
 func (p *interopCELTypeProvider) FindStructType(typeName string) (*types.Type, bool) {
 	if et, found := p.FindType(typeName); found {
@@ -813,7 +820,7 @@ func (p *interopCELTypeProvider) FindStructFieldNames(typeName string) ([]string
 // FindStructFieldType returns a types.FieldType instance for the given fully-qualified typeName and field
 // name, if one exists.
 //
-// This method proxies to the underyling ref.TypeProvider's FindFieldType method and converts protobuf type
+// This method proxies to the underlying ref.TypeProvider's FindFieldType method and converts protobuf type
 // into a native type representation. If the conversion fails, the type is listed as not found.
 func (p *interopCELTypeProvider) FindStructFieldType(structType, fieldName string) (*types.FieldType, bool) {
 	if ft, found := p.FindFieldType(structType, fieldName); found {