Use errors.As

open-telemetry · Jun 8, 2023 · 9550a1e · 9550a1e
1 parent d225b2d
commit 9550a1e
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Showing 3 changed files with 30 additions and 26 deletions.
diff --git a/pkg/ottl/expression.go b/pkg/ottl/expression.go
@@ -133,10 +133,12 @@ func (l *listGetter[K]) Get(ctx context.Context, tCtx K) (interface{}, error) {
 	return evaluated, nil
 }
 
-type TypeError string
+type TypeError struct {
+	msg string
+}
 
 func (t TypeError) Error() string {
-	return string(t)
+	return t.msg
 }
 
 // StringGetter is a Getter that must return a string.
@@ -155,7 +157,7 @@ func (g StandardStringGetter[K]) Get(ctx context.Context, tCtx K) (string, error
 		return "", err
 	}
 	if val == nil {
-		return "", TypeError("expected string but got nil")
+		return "", &TypeError{msg: "expected string but got nil"}
 	}
 	switch v := val.(type) {
 	case string:
@@ -164,9 +166,9 @@ func (g StandardStringGetter[K]) Get(ctx context.Context, tCtx K) (string, error
 		if v.Type() == pcommon.ValueTypeStr {
 			return v.Str(), nil
 		}
-		return "", TypeError(fmt.Sprintf("expected string but got %v", v.Type()))
+		return "", &TypeError{msg: fmt.Sprintf("expected string but got %v", v.Type())}
 	default:
-		return "", TypeError(fmt.Sprintf("expected string but got %T", val))
+		return "", &TypeError{msg: fmt.Sprintf("expected string but got %T", val)}
 	}
 }
 
@@ -184,7 +186,7 @@ func (g StandardIntGetter[K]) Get(ctx context.Context, tCtx K) (int64, error) {
 		return 0, err
 	}
 	if val == nil {
-		return 0, TypeError("expected int64 but got nil")
+		return 0, &TypeError{msg: "expected int64 but got nil"}
 	}
 	switch v := val.(type) {
 	case int64:
@@ -193,9 +195,9 @@ func (g StandardIntGetter[K]) Get(ctx context.Context, tCtx K) (int64, error) {
 		if v.Type() == pcommon.ValueTypeInt {
 			return v.Int(), nil
 		}
-		return 0, TypeError(fmt.Sprintf("expected int64 but got %v", v.Type()))
+		return 0, &TypeError{msg: fmt.Sprintf("expected int64 but got %v", v.Type())}
 	default:
-		return 0, TypeError(fmt.Sprintf("expected int64 but got %T", val))
+		return 0, &TypeError{msg: fmt.Sprintf("expected int64 but got %T", val)}
 	}
 }
 
@@ -213,7 +215,7 @@ func (g StandardFloatGetter[K]) Get(ctx context.Context, tCtx K) (float64, error
 		return 0, err
 	}
 	if val == nil {
-		return 0, TypeError("expected float64 but got nil")
+		return 0, &TypeError{msg: "expected float64 but got nil"}
 	}
 	switch v := val.(type) {
 	case float64:
@@ -222,9 +224,9 @@ func (g StandardFloatGetter[K]) Get(ctx context.Context, tCtx K) (float64, error
 		if v.Type() == pcommon.ValueTypeDouble {
 			return v.Double(), nil
 		}
-		return 0, TypeError(fmt.Sprintf("expected float64 but got %v", v.Type()))
+		return 0, &TypeError{msg: fmt.Sprintf("expected float64 but got %v", v.Type())}
 	default:
-		return 0, TypeError(fmt.Sprintf("expected float64 but got %T", val))
+		return 0, &TypeError{msg: fmt.Sprintf("expected float64 but got %T", val)}
 	}
 }
 
@@ -242,7 +244,7 @@ func (g StandardPMapGetter[K]) Get(ctx context.Context, tCtx K) (pcommon.Map, er
 		return pcommon.Map{}, err
 	}
 	if val == nil {
-		return pcommon.Map{}, TypeError("expected pcommon.Map but got nil")
+		return pcommon.Map{}, &TypeError{msg: "expected pcommon.Map but got nil"}
 	}
 	switch v := val.(type) {
 	case pcommon.Map:
@@ -251,7 +253,7 @@ func (g StandardPMapGetter[K]) Get(ctx context.Context, tCtx K) (pcommon.Map, er
 		if v.Type() == pcommon.ValueTypeMap {
 			return v.Map(), nil
 		}
-		return pcommon.Map{}, TypeError(fmt.Sprintf("expected pcommon.Map but got %v", v.Type()))
+		return pcommon.Map{}, &TypeError{msg: fmt.Sprintf("expected pcommon.Map but got %v", v.Type())}
 	case map[string]any:
 		m := pcommon.NewMap()
 		err = m.FromRaw(v)
@@ -260,7 +262,7 @@ func (g StandardPMapGetter[K]) Get(ctx context.Context, tCtx K) (pcommon.Map, er
 		}
 		return m, nil
 	default:
-		return pcommon.Map{}, TypeError(fmt.Sprintf("expected pcommon.Map but got %T", val))
+		return pcommon.Map{}, &TypeError{msg: fmt.Sprintf("expected pcommon.Map but got %T", val)}
 	}
 }
 

diff --git a/pkg/ottl/ottlfuncs/func_is_map.go b/pkg/ottl/ottlfuncs/func_is_map.go
@@ -5,6 +5,7 @@ package ottlfuncs // import "github.com/open-telemetry/opentelemetry-collector-c
 
 import (
 	"context"
+	"errors"
 	"fmt"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
@@ -31,13 +32,13 @@ func createIsMapFunction[K any](_ ottl.FunctionContext, oArgs ottl.Arguments) (o
 func isMap[K any](target ottl.PMapGetter[K]) ottl.ExprFunc[K] {
 	return func(ctx context.Context, tCtx K) (interface{}, error) {
 		_, err := target.Get(ctx, tCtx)
-		switch err.(type) {
-		case ottl.TypeError:
-			return false, nil
-		case nil:
+		if err == nil {
 			return true, nil
-		default:
-			return false, err
 		}
+		var typeError *ottl.TypeError
+		if errors.As(err, &typeError) {
+			return false, nil
+		}
+		return false, err
 	}
 }
diff --git a/pkg/ottl/ottlfuncs/func_is_string.go b/pkg/ottl/ottlfuncs/func_is_string.go
@@ -5,6 +5,7 @@ package ottlfuncs // import "github.com/open-telemetry/opentelemetry-collector-c
 
 import (
 	"context"
+	"errors"
 	"fmt"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
@@ -31,13 +32,13 @@ func createIsStringFunction[K any](_ ottl.FunctionContext, oArgs ottl.Arguments)
 func isStringFunc[K any](target ottl.StringGetter[K]) ottl.ExprFunc[K] {
 	return func(ctx context.Context, tCtx K) (interface{}, error) {
 		_, err := target.Get(ctx, tCtx)
-		switch err.(type) {
-		case ottl.TypeError:
-			return false, nil
-		case nil:
+		if err == nil {
 			return true, nil
-		default:
-			return false, err
 		}
+		var typeError *ottl.TypeError
+		if errors.As(err, &typeError) {
+			return false, nil
+		}
+		return false, err
 	}
 }