Review fixes

config/config.go

@@ -211,19 +211,19 @@ func (c *Config) Validate() error {
 		// we can only have the same provider for all layers.
 		// This allow us to track what the first found provider
 		// is.
-		currProvider := ""
+		currentProvider := ""
 		isMVTProvider := false
 		for layerKey, l := range m.Layers {
 			pname, _, err := l.ProviderLayerName()
 			if err != nil {
 				return err
 			}
 
-			if currProvider == "" {
+			if currentProvider == "" {
 				// This is the first provider we found.
 				// For MVTProviders all others need to be the same, so store it
 				// so we can check later
-				currProvider = pname
+				currentProvider = pname
 			}
 
 			isMvt, doesExists := mvtproviders[pname]
@@ -240,13 +240,13 @@ func (c *Config) Validate() error {
 			isMVTProvider = isMVTProvider || isMvt
 
 			// only need to do this check if we are dealing with MVTProviders
-			if isMVTProvider && pname != currProvider {
+			if isMVTProvider && pname != currentProvider {
 				// for mvt_providers we can only have the same provider
 				// for all layers
 				// check to see
 				if mvtproviders[pname] || isMVTProvider {
 					return ErrMVTDifferentProviders{
-						Original: currProvider,
+						Original: currentProvider,
 						Current:  pname,
 					}
 				}

provider/query_parameter.go

@@ -44,25 +44,22 @@ func (param *QueryParameter) ToValue(rawValue string) (QueryParameterValue, erro
 func (param *QueryParameter) ToDefaultValue() (QueryParameterValue, error) {
 	if len(param.DefaultValue) > 0 {
 		val, err := ParamTypeDecoders[param.Type](param.DefaultValue)
-		if err != nil {
-			return QueryParameterValue{}, err
-		}
 		return QueryParameterValue{
 			Token:    param.Token,
 			SQL:      param.SQL,
 			Value:    val,
 			RawParam: param.Name,
 			RawValue: "",
-		}, nil
-	} else if len(param.DefaultSQL) > 0 {
+		}, err
+	}
+	if len(param.DefaultSQL) > 0 {
 		return QueryParameterValue{
 			Token:    param.Token,
 			SQL:      param.DefaultSQL,
 			Value:    nil,
 			RawParam: param.Name,
 			RawValue: "",
 		}, nil
-	} else {
-		return QueryParameterValue{}, fmt.Errorf("the required parameter %s is not specified", param.Name)
 	}
+	return QueryParameterValue{}, fmt.Errorf("the required parameter %s is not specified", param.Name)
 }

provider/query_parameter_value.go

@@ -6,7 +6,7 @@ import (
 )
 
 // Query parameter holds normalized parameter data ready to be inserted in the
-//  final query
+// final query
 type QueryParameterValue struct {
 	// Token to replace e.g., !TOKEN!
 	Token string
@@ -24,42 +24,51 @@ type QueryParameterValue struct {
 type Params map[string]QueryParameterValue
 
 // ReplaceParams substitutes configured query parameter tokens for their values
-//  within the provided SQL string
+// within the provided SQL string
 func (params Params) ReplaceParams(sql string, args *[]interface{}) string {
 	if params == nil {
 		return sql
 	}
 
-	cache := make(map[string]string)
+	var (
+		cache = make(map[string]string)
+		sb    strings.Builder
+	)
 
 	for _, token := range ParameterTokenRegexp.FindAllString(sql, -1) {
-		resultSQL := ""
+		resultSQL, ok := cache[token]
+		if ok {
+			// Already have it cached, replace the token and move on.
+			sql = strings.ReplaceAll(sql, token, resultSQL)
+			continue
+		}
 
-		if t, ok := cache[token]; ok {
-			resultSQL = t
-		} else if param, ok := params[token]; !ok {
+		param, ok := params[token]
+		if !ok {
 			// Unknown token, ignoring
 			continue
-		} else {
-			// Replace every ? in the param's SQL with a positional argument
-			sb := strings.Builder{}
-			sb.Grow(len(param.SQL))
-			argFound := false
-			for _, c := range param.SQL {
-				if c == '?' {
-					if !argFound {
-						*args = append(*args, param.Value)
-						argFound = true
-					}
-					sb.WriteString(fmt.Sprintf("$%d", len(*args)))
-				} else {
-					sb.WriteRune(c)
-				}
+		}
+
+		sb.Reset()
+		sb.Grow(len(param.SQL))
+		argFound := false
+
+		// Replace every `?` in the param's SQL with a positional argument
+		for _, c := range param.SQL {
+			if c != '?' {
+				sb.WriteRune(c)
+				continue
+			}
+
+			if !argFound {
+				*args = append(*args, param.Value)
+				argFound = true
 			}
-			resultSQL = sb.String()
-			cache[token] = resultSQL
+			sb.WriteString(fmt.Sprintf("$%d", len(*args)))
 		}
 
+		resultSQL = sb.String()
+		cache[token] = resultSQL
 		sql = strings.ReplaceAll(sql, token, resultSQL)
 	}
 

tile.go

@@ -17,7 +17,7 @@ const (
 
 var UnknownConversionError = fmt.Errorf("do not know how to convert value to requested value")
 
-//Tile slippy map tilenames
+// Tile slippy map tilenames
 // http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames
 type Tile struct {
 	Z         uint
@@ -198,7 +198,7 @@ func (t *Tile) ZLevel() uint {
 	return t.Z
 }
 
-//ZRes takes a web mercator zoom level and returns the pixel resolution for that
+// ZRes takes a web mercator zoom level and returns the pixel resolution for that
 // scale, assuming t.Extent x t.Extent pixel tiles. Non-integer zoom levels are accepted.
 // ported from: https://raw.githubusercontent.com/mapbox/postgis-vt-util/master/postgis-vt-util.sql
 // 40075016.6855785 is the equator in meters for WGS84 at z=0