Handle integer conversion errors (#425)

When converting a double larger or equal to math.MaxInt64 to an integer, it previously overflowed silently. It now returns an explicit error.

This fixes along the way, the math.abs(-9223372036854775808) issue.

document/cast.go

@@ -14,11 +14,6 @@ func CastAs(v types.Value, t types.ValueType) (types.Value, error) {
 		return v, nil
 	}
 
-	// Null values always remain null.
-	if v.Type() == types.NullValue {
-		return v, nil
-	}
-
 	switch t {
 	case types.BoolValue:
 		return CastAsBool(v)
@@ -45,6 +40,11 @@ func CastAs(v types.Value, t types.ValueType) (types.Value, error) {
 // it fails if the text doesn't contain a valid boolean.
 // Any other type is considered an invalid cast.
 func CastAsBool(v types.Value) (types.Value, error) {
+	// Null values always remain null.
+	if v.Type() == types.NullValue {
+		return v, nil
+	}
+
 	switch v.Type() {
 	case types.BoolValue:
 		return v, nil
@@ -70,6 +70,11 @@ func CastAsBool(v types.Value) (types.Value, error) {
 // It fails if the text doesn't contain a valid float value.
 // Any other type is considered an invalid cast.
 func CastAsInteger(v types.Value) (types.Value, error) {
+	// Null values always remain null.
+	if v.Type() == types.NullValue {
+		return v, nil
+	}
+
 	switch v.Type() {
 	case types.IntegerValue:
 		return v, nil
@@ -79,7 +84,11 @@ func CastAsInteger(v types.Value) (types.Value, error) {
 		}
 		return types.NewIntegerValue(0), nil
 	case types.DoubleValue:
-		return types.NewIntegerValue(int64(v.V().(float64))), nil
+		f := v.V().(float64)
+		if f > 0 && int64(f) < 0 {
+			return nil, stringutil.Errorf("integer out of range")
+		}
+		return types.NewIntegerValue(int64(f)), nil
 	case types.TextValue:
 		i, err := strconv.ParseInt(v.V().(string), 10, 64)
 		if err != nil {
@@ -102,6 +111,11 @@ func CastAsInteger(v types.Value) (types.Value, error) {
 // it fails if the text doesn't contain a valid float value.
 // Any other type is considered an invalid cast.
 func CastAsDouble(v types.Value) (types.Value, error) {
+	// Null values always remain null.
+	if v.Type() == types.NullValue {
+		return v, nil
+	}
+
 	switch v.Type() {
 	case types.DoubleValue:
 		return v, nil
@@ -121,6 +135,11 @@ func CastAsDouble(v types.Value) (types.Value, error) {
 // CastAsText returns a JSON representation of v.
 // If the representation is a string, it gets unquoted.
 func CastAsText(v types.Value) (types.Value, error) {
+	// Null values always remain null.
+	if v.Type() == types.NullValue {
+		return v, nil
+	}
+
 	switch v.Type() {
 	case types.TextValue:
 		return v, nil
@@ -142,6 +161,11 @@ func CastAsText(v types.Value) (types.Value, error) {
 // Text: decodes a base64 string, otherwise fails.
 // Any other type is considered an invalid cast.
 func CastAsBlob(v types.Value) (types.Value, error) {
+	// Null values always remain null.
+	if v.Type() == types.NullValue {
+		return v, nil
+	}
+
 	if v.Type() == types.BlobValue {
 		return v, nil
 	}
@@ -164,6 +188,11 @@ func CastAsBlob(v types.Value) (types.Value, error) {
 // Text: decodes a JSON array, otherwise fails.
 // Any other type is considered an invalid cast.
 func CastAsArray(v types.Value) (types.Value, error) {
+	// Null values always remain null.
+	if v.Type() == types.NullValue {
+		return v, nil
+	}
+
 	if v.Type() == types.ArrayValue {
 		return v, nil
 	}
@@ -185,6 +214,11 @@ func CastAsArray(v types.Value) (types.Value, error) {
 // Text: decodes a JSON object, otherwise fails.
 // Any other type is considered an invalid cast.
 func CastAsDocument(v types.Value) (types.Value, error) {
+	// Null values always remain null.
+	if v.Type() == types.NullValue {
+		return v, nil
+	}
+
 	if v.Type() == types.DocumentValue {
 		return v, nil
 	}

document/cast_test.go

@@ -1,6 +1,7 @@
 package document
 
 import (
+	"math"
 	"testing"
 
 	"github.com/genjidb/genji/types"
@@ -70,6 +71,7 @@ func TestCastAs(t *testing.T) {
 			{blobV, nil, true},
 			{arrayV, nil, true},
 			{docV, nil, true},
+			{types.NewDoubleValue(math.MaxInt64 + 1), nil, true},
 		})
 	})
 

internal/expr/functions/testdata/math_functions.sql

@@ -17,6 +17,8 @@ NULL
 2.0
 ! math.abs('foo')
 'cannot cast "foo" as double'
+! math.abs(-9223372036854775808)
+'integer out of range'
 
 -- test: math.acos
 > math.acos(NULL)

internal/testutil/expr.go

@@ -152,7 +152,7 @@ func ExprRunner(t *testing.T, testfile string) {
 						require.NoError(t, err)
 
 						// eval it to get a proper Value
-						want, err := e.Eval(emptyEnv)
+						want, err := e.Eval(environment.New(nil))
 						require.NoError(t, err)
 
 						// parse the given expr
@@ -160,7 +160,7 @@ func ExprRunner(t *testing.T, testfile string) {
 						require.NoError(t, err)
 
 						// eval it to get a proper Value
-						got, err := e.Eval(emptyEnv)
+						got, err := e.Eval(environment.New(nil))
 						require.NoError(t, err)
 
 						// finally, compare those two
@@ -170,12 +170,14 @@ func ExprRunner(t *testing.T, testfile string) {
 					t.Run("NOK "+stmt.Expr, func(t *testing.T) {
 						// parse the given epxr
 						e, err := parser.NewParser(strings.NewReader(stmt.Expr)).ParseExpr()
-						require.NoError(t, err)
-
+						if err != nil {
+							require.Regexp(t, regexp.MustCompile(regexp.QuoteMeta(stmt.Res)), err.Error())
+						} else {
 							// eval it, it should return an error
-						_, err = e.Eval(emptyEnv)
+							_, err = e.Eval(environment.New(nil))
 							require.NotNilf(t, err, "expected expr `%s` to return an error, got nil", stmt.Expr)
 							require.Regexp(t, regexp.MustCompile(regexp.QuoteMeta(stmt.Res)), err.Error())
+						}
 					})
 				}
 			}