fix coalesce

Author: James Cor

sql/expression/function/coalesce_test.go

@@ -152,6 +152,16 @@ func TestCoalesce(t *testing.T) {
 			typ:      types.Float64,
 			nullable: false,
 		},
+		{
+			name: "coalesce(json({'a': 'a \n b'}), '')",
+			input: []sql.Expression{
+				expression.NewLiteral("{\"a\": \"one \\n two\"}", types.JSON),
+				expression.NewLiteral("", types.LongText),
+			},
+			expected: "{\"a\": \"one \\n two\"}",
+			typ:      types.LongText,
+			nullable: false,
+		},
 		{
 			name: "coalesce(sysInt, sysInt)",
 			input: []sql.Expression{

sql/types/json_value.go

@@ -43,7 +43,7 @@ func JsonToMySqlString(jsonWrapper sql.JSONWrapper) (string, error) {
 	return marshalToMySqlString(val)
 }
 
-// JsonToMySqlString generates a byte slice representation of a sql.JSONWrapper that is compatible with MySQL's JSON output, including spaces.
+// JsonToMySqlBytes generates a byte slice representation of a sql.JSONWrapper that is compatible with MySQL's JSON output, including spaces.
 func JsonToMySqlBytes(jsonWrapper sql.JSONWrapper) ([]byte, error) {
 	val, err := jsonWrapper.ToInterface()
 	if err != nil {
@@ -630,8 +630,8 @@ func compareJSONArray(a JsonArray, b interface{}) (int, error) {
 func compareJSONObject(a JsonObject, b interface{}) (int, error) {
 	switch b := b.(type) {
 	case
-		bool,
-		JsonArray:
+			bool,
+			JsonArray:
 		// a is lower precedence
 		return -1, nil
 
@@ -662,9 +662,9 @@ func compareJSONObject(a JsonObject, b interface{}) (int, error) {
 func compareJSONString(a string, b interface{}) (int, error) {
 	switch b := b.(type) {
 	case
-		bool,
-		JsonArray,
-		JsonObject:
+			bool,
+			JsonArray,
+			JsonObject:
 		// a is lower precedence
 		return -1, nil
 
@@ -680,10 +680,10 @@ func compareJSONString(a string, b interface{}) (int, error) {
 func compareJSONNumber(a float64, b interface{}) (int, error) {
 	switch b := b.(type) {
 	case
-		bool,
-		JsonArray,
-		JsonObject,
-		string:
+			bool,
+			JsonArray,
+			JsonObject,
+			string:
 		// a is lower precedence
 		return -1, nil
 	case int:

sql/types/strings.go

@@ -29,7 +29,6 @@ import (
 	"github.com/shopspring/decimal"
 	"gopkg.in/src-d/go-errors.v1"
 
-	"github.com/dolthub/go-mysql-server/internal/strings"
 	"github.com/dolthub/go-mysql-server/sql"
 	"github.com/dolthub/go-mysql-server/sql/encodings"
 )
@@ -416,7 +415,8 @@ func ConvertToBytes(ctx context.Context, v interface{}, t sql.StringType, dest [
 		if err != nil {
 			return nil, err
 		}
-		val, err = strings.UnquoteBytes(val)
+		// TODO: why do we do this?
+		//val, err = strings.UnquoteBytes(val)
 		if err != nil {
 			return nil, err
 		}